It's scary how many people warm up a car the wrong way....
12-20-2000, 11:49 AM
#41
Guest
Posts: n/a
OH, BTW--->
Originally posted by JimW
I was in fact ASE certified, just didn't renew it when they expired. I didn't do my own tranny work because I was no longer a technician, and since I only have a one-car garage with a one car driveway, I didn't have the space to park the car for a couple of weeks while I rebuilt a tranny. It's almost impossible to rebuild a tranny when you only have 1-2 hrs a day to work on it. You're right, it's not rocket science. (I have a 9-5 now, or should I say a 8:30-6:30) Also keep in mind, I do have a degree in Automotive Technology, as I was on my way to becoming an automotive engineer. I had a 3.5 GPA, in classes like Alternate Powerplants, Advanced Thermodynamics, Advanced Metallurgy, Fundamentals of innternal combustion engines, Physics I, II, and Advanced Physics. Hydraulics, Engine analysis (where we dismantled non-working engines and had to rebuild them to run on an engine dyno)
Then of course, there's the other stuff :blueprinting, welding, engine and chassis lab, refrigeration, etc. I've got a pretty extensive background in the study and repair of autos, for someone of my age.
As far as "experience", I was changing oil at 12, pulled the top end off my first engine at the same age. Worked for a small repair place in Brooklyn from 15-18. I had enough experience to know how to wire spark plug wires for any domestic engine with all the existing ones removed. I'm the same person who could tell you the model and engine size of a car just by hearing it start up.
As far as the other mods. I installed the ones that I wanted, and paid for the others. The Y-pipe I wouldn't attempt because of the lack of air tools and time. I went to an exhaust shop that I know the owner of, and we installed it together.
I still haven't heard any technician (that I know of, or that I worked with) say that idling an engine up to operating temperature will harm that engine, neither did I see you post specifically what type of damage that it can cause. Gaskets? I don't think so. The job of a gasket is to provide a liquid and or gas barrier between the junction of two metal (or other material) joints.
Not trying to discredit you or anyone else. I just have to question the validity of what Sikorsky wrote.
Now, as far as the VQ and my 2.7T motors are concerned, although they may be different, they are still similar. With the exception of the Turbos, I still have a 2.7L aluminum block engine that is spinning those turbos. If that's the case, by allowing the turbos to be fed with oil sufficiently before driving off, I'm killing the long block. Either way I lose. That's why I have trouble believing what Sikorsky says.
So here's my breakdown:
first mentioned was oil pressure. I countered that most engines make full oil pressure just over idle speed (which is true) In most cases (say 75%) the oil pump is pumping full supply and pressure at a measly 11-1300 rpm.
Then the oil "pooling" was mentioned. I responded that pooling shouldn't occur, as full pressure is reached just over idle.
Then you mentioned "fuel dilution of the oil, and running rich" I can agree with fuel dilution of the oil, but in the modern era of ECU's and OBD, the car isn't running very rich, only in the startup phase. Once running, the ECU will try to lean it out asap, to clean up the exhaust emissions. That's another reason for the pre-cats. Placing the pre cats close to the exhaust ports of the cylinders makes sure that they "light-off" quickly, very soon after the engine starts. Now, to make what I said as clear as mud. Changing the oil at 3,000 miles will make sure that there is no damage to your engine due to motor oil breakdown, or acidic content. (I don't believe that Nissan calls for 3k oil changes in it's light duty cycle, I believe the sever duty cycle calls for 3k oil changes. Severe duty meaning door-to door service, operation in extreme temps or in dusty enviromnents)
I still don't agree. Idling an engine before driving it up to full temperature is NOT going to damage it.
Originally posted by Dave B
Jim-
You're comparing your twin turbo 2.7 to the VQ. Sorry buddy, these are two different animals. A turbo needs to idled longer to get full circulation thru the most expensive part of the motor-the two turbos plus you should idle it down after hard driving to prevent "coking" of the turbos.
Believe what you want, but Sikorsky is also ASE certified, a mechanic, has numerous other automotive credientials, and is highly respected in his profession. Out of curosity, if you were ASE-certified, then why didn't you do all your tranny work and install of all you mods on the Max? Rebuilding a tranny and installing a torque converter isn't a rocket science. I don't know where you get your info other than just from "experience". You haven't been apart of engine wear analysis nor have you researched the information with engineers from auto makers, oil companies, and gas companies. Like I said, believe what you want. But more often than not, most techs and engineers will tell you what Sikorsky tells you.
I do "work" out my motor a bit, but not near as often as many do in this forum. I might run it up to 5000-6000 in 2nd and some of 3rd 5 times a week, but I don't speed shift the car. I think operating a motor in it's normal operating range of idle to 6500 rpms isn't gonna do significant damage to the motor as long as the engine and tranny are warmed up. As many know, the cold start is the hardest operation on your engine. Anyways, operating an engine in it's normal operating range allows the motor to be broken in fully. By operating a motor from idle to 4000rpms nearly all of it's life and has redline of 6500 rpms will mostly result in a quick failure of the gaskets if you start running it above 4000. WHy? Because the gaskets are not used to increased pressure of operating the motor at such high rpms therefore they fail and leak (or blow). I think you do more damage to your transmission by shifting it hard at a high rpm when racing then you do damage to the motor revving it high (not exceeding redline).
Dave
Jim-
You're comparing your twin turbo 2.7 to the VQ. Sorry buddy, these are two different animals. A turbo needs to idled longer to get full circulation thru the most expensive part of the motor-the two turbos plus you should idle it down after hard driving to prevent "coking" of the turbos.
Believe what you want, but Sikorsky is also ASE certified, a mechanic, has numerous other automotive credientials, and is highly respected in his profession. Out of curosity, if you were ASE-certified, then why didn't you do all your tranny work and install of all you mods on the Max? Rebuilding a tranny and installing a torque converter isn't a rocket science. I don't know where you get your info other than just from "experience". You haven't been apart of engine wear analysis nor have you researched the information with engineers from auto makers, oil companies, and gas companies. Like I said, believe what you want. But more often than not, most techs and engineers will tell you what Sikorsky tells you.
I do "work" out my motor a bit, but not near as often as many do in this forum. I might run it up to 5000-6000 in 2nd and some of 3rd 5 times a week, but I don't speed shift the car. I think operating a motor in it's normal operating range of idle to 6500 rpms isn't gonna do significant damage to the motor as long as the engine and tranny are warmed up. As many know, the cold start is the hardest operation on your engine. Anyways, operating an engine in it's normal operating range allows the motor to be broken in fully. By operating a motor from idle to 4000rpms nearly all of it's life and has redline of 6500 rpms will mostly result in a quick failure of the gaskets if you start running it above 4000. WHy? Because the gaskets are not used to increased pressure of operating the motor at such high rpms therefore they fail and leak (or blow). I think you do more damage to your transmission by shifting it hard at a high rpm when racing then you do damage to the motor revving it high (not exceeding redline).
Dave
Then of course, there's the other stuff :blueprinting, welding, engine and chassis lab, refrigeration, etc. I've got a pretty extensive background in the study and repair of autos, for someone of my age.
As far as "experience", I was changing oil at 12, pulled the top end off my first engine at the same age. Worked for a small repair place in Brooklyn from 15-18. I had enough experience to know how to wire spark plug wires for any domestic engine with all the existing ones removed. I'm the same person who could tell you the model and engine size of a car just by hearing it start up.
As far as the other mods. I installed the ones that I wanted, and paid for the others. The Y-pipe I wouldn't attempt because of the lack of air tools and time. I went to an exhaust shop that I know the owner of, and we installed it together.
I still haven't heard any technician (that I know of, or that I worked with) say that idling an engine up to operating temperature will harm that engine, neither did I see you post specifically what type of damage that it can cause. Gaskets? I don't think so. The job of a gasket is to provide a liquid and or gas barrier between the junction of two metal (or other material) joints.
Not trying to discredit you or anyone else. I just have to question the validity of what Sikorsky wrote.
Now, as far as the VQ and my 2.7T motors are concerned, although they may be different, they are still similar. With the exception of the Turbos, I still have a 2.7L aluminum block engine that is spinning those turbos. If that's the case, by allowing the turbos to be fed with oil sufficiently before driving off, I'm killing the long block. Either way I lose. That's why I have trouble believing what Sikorsky says.
So here's my breakdown:
first mentioned was oil pressure. I countered that most engines make full oil pressure just over idle speed (which is true) In most cases (say 75%) the oil pump is pumping full supply and pressure at a measly 11-1300 rpm.
Then the oil "pooling" was mentioned. I responded that pooling shouldn't occur, as full pressure is reached just over idle.
Then you mentioned "fuel dilution of the oil, and running rich" I can agree with fuel dilution of the oil, but in the modern era of ECU's and OBD, the car isn't running very rich, only in the startup phase. Once running, the ECU will try to lean it out asap, to clean up the exhaust emissions. That's another reason for the pre-cats. Placing the pre cats close to the exhaust ports of the cylinders makes sure that they "light-off" quickly, very soon after the engine starts. Now, to make what I said as clear as mud. Changing the oil at 3,000 miles will make sure that there is no damage to your engine due to motor oil breakdown, or acidic content. (I don't believe that Nissan calls for 3k oil changes in it's light duty cycle, I believe the sever duty cycle calls for 3k oil changes. Severe duty meaning door-to door service, operation in extreme temps or in dusty enviromnents)
I still don't agree. Idling an engine before driving it up to full temperature is NOT going to damage it.
I re-read your post and saw this statement. This statement is true, but let me explain.
This is only true in the first few seconds when the car is started after sitting overnight (or an extended period of time) After all the oil has drained back into the crankcase, and there is NO oil in any of the passages or lining the cylinder walls, or on the cam bearings or on the valves. It has been estimated that 80% of an engines wear happens at that precise moment, that moment when you turn the key, the engine starts, and it takes about 2 seconds for the cold, thick oil to circulate to all the moving parts, and that causes a significant amount of wear. More wear than just about anything else would. That's why those "pre-lubers" were the hot ticket about 5-6 years ago. People would pay $200-$300 to have these prelubers pressurize the oil passageways before they started their cars. Great idea, until you think of this. Almost no one could attribute an engine failure to the friction that occurs at startup. Engines simply last longer today, 150k-200k is a reality with regular oil changes and maintenance.
12-20-2000, 11:57 AM
#43
Re: Not entirely true Dave--->
u da man.
i mean. if you leave the car sitting. that's not going to damage the car as much as reving hard when the car is cold. i always start the car, wait like 30 seconds then drive off. but sometimes, when waiting for people to get in the car, it often idles for 3 or 4 minutes, what ever fuel is in excess is burned off, there SHOULDN'T be any wear or else something is messed up with your engine.
think of all those people who start their cars in the midwest during winter, heck if they can even feel their toes when they push in the clutch, i'm sure the want to warm up before driving off. yeah, the ECU makes the car run rich, but that's to make sure everything all the fuel previously inside the engine is "cleared" out before the engine is run again.. i think..
i mean. if you leave the car sitting. that's not going to damage the car as much as reving hard when the car is cold. i always start the car, wait like 30 seconds then drive off. but sometimes, when waiting for people to get in the car, it often idles for 3 or 4 minutes, what ever fuel is in excess is burned off, there SHOULDN'T be any wear or else something is messed up with your engine.
think of all those people who start their cars in the midwest during winter, heck if they can even feel their toes when they push in the clutch, i'm sure the want to warm up before driving off. yeah, the ECU makes the car run rich, but that's to make sure everything all the fuel previously inside the engine is "cleared" out before the engine is run again.. i think..
Originally posted by JimW
Oil pooling is not a major concern, as a matter of fact, just about every modern that I have ever worked on provides maximum oil pressure (and flow) at just over idle. Why? To prevent the unlikely situation that someone gets the revs up faster than the oil pump can provide oil pressure. No pressure/oil and high revs spells disaster. Warming up an engine excessively is not necessary, but it surely will not harm an engine in any way. So long as the engine gets up to operating temperature, then any of the "enriched" particulates will burn off, and there will be no increased wear or damage to the engine.
A idle warm isn't the fastest way to warm up an engine, but it surely isn't dangerous. That I can guarantee. [/I]
Oil pooling is not a major concern, as a matter of fact, just about every modern that I have ever worked on provides maximum oil pressure (and flow) at just over idle. Why? To prevent the unlikely situation that someone gets the revs up faster than the oil pump can provide oil pressure. No pressure/oil and high revs spells disaster. Warming up an engine excessively is not necessary, but it surely will not harm an engine in any way. So long as the engine gets up to operating temperature, then any of the "enriched" particulates will burn off, and there will be no increased wear or damage to the engine.
A idle warm isn't the fastest way to warm up an engine, but it surely isn't dangerous. That I can guarantee. [/I]
12-20-2000, 12:03 PM
#44
Senior Member
Join Date: Nov 2000
Posts: 915
Tom thinks to himself, "Now look what you've made me do...", as he lets his Maxima idle...
It's all the weathermen's fault...!! Northeast winters are COLD!!
-Tom
It's all the weathermen's fault...!! Northeast winters are COLD!!
-Tom
Originally posted by TBag
My Name is Tim, and I am A Car Abuser!!!!!!!
My Name is Tim, and I am A Car Abuser!!!!!!!
12-20-2000, 12:10 PM
#45
Not DAVEB the parts guy
Thread Starter
Join Date: Aug 2000
Posts: 8,555
Jim-
Like I said, believe what you want. You do your own thing and I'll do mine
You do have a lot of experience tearing down engines and such, but I still don't see information that shows you've researched anything. Let's think about this a little though. Why WOULD you want to idle warm your car anyways? It takes too long and wastes a lot of gas. Any extended idling isn't good for any gasoline motor. Why do you think companies use diesel motors on service vehicles that run hydraulic equipment off the motor? Because gasoline powered engines don't fair well to extended idling. Deposits form, the cats clog, the oil doesn't last long, etc. I've talked to lots of contractors that work for my company and nearly none of them choose the cheaper gasoline powered service vehicle because they know that down the road, the diesel motor will last much longer at an idle than a gasoline powered motor. Why does the diesel motor last longer, because it is in it's normal operating range at near idle. Most diesel motors operate in the 1000-3500 rpm range therefore they are at near peak effiecency at idle. A gasoline powered truck motor has an operating range of typically 2300-4800 rpms. Also, I don't know where you get the idea that the oil pump is at near capacity at idle. My 94 Z28 had a oil pressure gauge. On a very cold start, the psi would jump to about 60% capacity on start up and drop to about 30% after 1 minute. Once the engine was warm the psi about be at about 15% capacity at idle. At full throttle, that baby would be pinned at near 100% capacity. Point is, it flucuated with rpms.
BTW, I installed my y-pipe that had been on my car for over 3 years and thru snowy and salty Kansas winters. All it took was a 20 minute Liquid wrench soaking and full socket set all the while in a home garage on jack stands. I've replaced my struts, installed front Koni adjustable struts, installed a B-pipe, brake pads, installed the lowering springs, installed my intake, fabricated a heat shield, wired in a shiftlight into my ECU, installed Prelude seats (had a shop weld on bracket extensions), and numerous other things most wouldn't venture to do. I'm not ASE certified. If you got the right tools and a good manual, the job is rather easy. I too work 8-5:30, play volleyball, play softball, and do LOTS of home improvement and I've always got time to play with my car
Jeff-
I don't know what else to tell you. Small amounts of gasoline become mixed in with the oil and this happens more often on the cold start. As the oil is brought up to iy's full viscosity and operating range, the petroleum hydrocarbons are released and burned off. Why you ask? Because gasoline is more explosive than oil. Why does it take a good 45 mintues to get a large percentage of the gas out of the oil? Because it takes a lot of circulating to get the contents "burned" out. It needs lots of "go arounds" to get the gas burned out. Smell your oil next time you change it. You'll notice it smells like gas. It didn't smell like that going in.
Dave
[Edited by Dave B on 12-20-2000 at 02:16 PM]
Like I said, believe what you want. You do your own thing and I'll do mine
You do have a lot of experience tearing down engines and such, but I still don't see information that shows you've researched anything. Let's think about this a little though. Why WOULD you want to idle warm your car anyways? It takes too long and wastes a lot of gas. Any extended idling isn't good for any gasoline motor. Why do you think companies use diesel motors on service vehicles that run hydraulic equipment off the motor? Because gasoline powered engines don't fair well to extended idling. Deposits form, the cats clog, the oil doesn't last long, etc. I've talked to lots of contractors that work for my company and nearly none of them choose the cheaper gasoline powered service vehicle because they know that down the road, the diesel motor will last much longer at an idle than a gasoline powered motor. Why does the diesel motor last longer, because it is in it's normal operating range at near idle. Most diesel motors operate in the 1000-3500 rpm range therefore they are at near peak effiecency at idle. A gasoline powered truck motor has an operating range of typically 2300-4800 rpms. Also, I don't know where you get the idea that the oil pump is at near capacity at idle. My 94 Z28 had a oil pressure gauge. On a very cold start, the psi would jump to about 60% capacity on start up and drop to about 30% after 1 minute. Once the engine was warm the psi about be at about 15% capacity at idle. At full throttle, that baby would be pinned at near 100% capacity. Point is, it flucuated with rpms. BTW, I installed my y-pipe that had been on my car for over 3 years and thru snowy and salty Kansas winters. All it took was a 20 minute Liquid wrench soaking and full socket set all the while in a home garage on jack stands. I've replaced my struts, installed front Koni adjustable struts, installed a B-pipe, brake pads, installed the lowering springs, installed my intake, fabricated a heat shield, wired in a shiftlight into my ECU, installed Prelude seats (had a shop weld on bracket extensions), and numerous other things most wouldn't venture to do. I'm not ASE certified. If you got the right tools and a good manual, the job is rather easy. I too work 8-5:30, play volleyball, play softball, and do LOTS of home improvement and I've always got time to play with my car
Jeff-
I don't know what else to tell you. Small amounts of gasoline become mixed in with the oil and this happens more often on the cold start. As the oil is brought up to iy's full viscosity and operating range, the petroleum hydrocarbons are released and burned off. Why you ask? Because gasoline is more explosive than oil. Why does it take a good 45 mintues to get a large percentage of the gas out of the oil? Because it takes a lot of circulating to get the contents "burned" out. It needs lots of "go arounds" to get the gas burned out. Smell your oil next time you change it. You'll notice it smells like gas. It didn't smell like that going in.
Dave
[Edited by Dave B on 12-20-2000 at 02:16 PM]
12-20-2000, 12:22 PM
#47
Dave I don't want to keep arguing but if you oil has enough gas in it to smell like gas, something is seriously wrong and the oil has long since lost it's film strength. Mine doesn't smell like gas when I change mine.
12-20-2000, 12:32 PM
#48
Not DAVEB the parts guy
Thread Starter
Join Date: Aug 2000
Posts: 8,555
Chebosto-
I live in Kansas City and the highs for the past 2 weeks have been in the teens and lows in the 5-10 below range. Hell, the snow on my car doesn't even melt in my garage. All my beer froze in my garage too!!!!
Anyways, my car is warmed up to the halfway mark after driving at 2500 rpms in 2nd gear for less than a mile. That means it takes approximately 2 minutes for my car to get into a nice operating temp plus my heater is working in 2 minutes. That means I'm driving in a ice box of a car for 2 minutes. I'd much rather do it this way then let my car sit there and idle to warm up. There have been times where I have had to let my car idle warm like when I forget something in the house and the car is on. Recently, I couldn't find my cell phone and my car sat idling for 10 minutes and the temp gauge was at 25%. THAT RIGHT THERE TELLS ME THAT DRIVING THE CAR RIGHT AWAY WARMS IT UP MUCH QUICKER.
To everyone who lives in a cold climate, try this. If it doesn't work, then you can tell me to go **** off. If it does work, I told you so.
One morning, let your car idle warm up and record how long it takes to get to the mid point on the temp gauge. The next morning, start your car and let it run for 30 seconds and then start driving. Record how long it takes to warm up. DON'T use your heater right away either. Turn it on when the gauge get close to the mid point. I am almost positive yor car will be warm in 2-3 minutes.
Dave
I live in Kansas City and the highs for the past 2 weeks have been in the teens and lows in the 5-10 below range. Hell, the snow on my car doesn't even melt in my garage. All my beer froze in my garage too!!!!
Anyways, my car is warmed up to the halfway mark after driving at 2500 rpms in 2nd gear for less than a mile. That means it takes approximately 2 minutes for my car to get into a nice operating temp plus my heater is working in 2 minutes. That means I'm driving in a ice box of a car for 2 minutes. I'd much rather do it this way then let my car sit there and idle to warm up. There have been times where I have had to let my car idle warm like when I forget something in the house and the car is on. Recently, I couldn't find my cell phone and my car sat idling for 10 minutes and the temp gauge was at 25%. THAT RIGHT THERE TELLS ME THAT DRIVING THE CAR RIGHT AWAY WARMS IT UP MUCH QUICKER.
To everyone who lives in a cold climate, try this. If it doesn't work, then you can tell me to go **** off. If it does work, I told you so.
One morning, let your car idle warm up and record how long it takes to get to the mid point on the temp gauge. The next morning, start your car and let it run for 30 seconds and then start driving. Record how long it takes to warm up. DON'T use your heater right away either. Turn it on when the gauge get close to the mid point. I am almost positive yor car will be warm in 2-3 minutes.
Dave
12-20-2000, 01:10 PM
#49
Senior Member
Join Date: Nov 2000
Posts: 915
Well this advice comes from the "no duh" department... (sorry about the sarcasm)... But it's sorta intuitive that an engine under load, and running at higher rpms (ie.. driven), will warm up faster than an engine under no load, with lower rpms (ie. idling)
The debate in this thread, however, is about which is healthier for your car... (so far, nobody has come out to say that idling your car is HEALTHIER...) the argument seems to be over whether or not cold idling actually harms the engine!! I dunno anything about this topic.. so I shall shut up now... and simply take it on blind faith that idling my car for a min or two will not harm it.... (all things in moderation.. right???!!!) Nor would i concede to idling it for 10 minutes, or driving after just 15 seconds... both of which are extremes proposed in this argument...
I'm comfortable in the middle!!!
The debate in this thread, however, is about which is healthier for your car... (so far, nobody has come out to say that idling your car is HEALTHIER...) the argument seems to be over whether or not cold idling actually harms the engine!! I dunno anything about this topic.. so I shall shut up now... and simply take it on blind faith that idling my car for a min or two will not harm it.... (all things in moderation.. right???!!!) Nor would i concede to idling it for 10 minutes, or driving after just 15 seconds... both of which are extremes proposed in this argument...
I'm comfortable in the middle!!!
Originally posted by Dave B
Chebosto-
I live in Kansas City and the highs for the past 2 weeks have been in the teens and lows in the 5-10 below range. Hell, the snow on my car doesn't even melt in my garage. All my beer froze in my garage too!!!!
Anyways, my car is warmed up to the halfway mark after driving at 2500 rpms in 2nd gear for less than a mile. That means it takes approximately 2 minutes for my car to get into a nice operating temp plus my heater is working in 2 minutes. That means I'm driving in a ice box of a car for 2 minutes. I'd much rather do it this way then let my car sit there and idle to warm up. There have been times where I have had to let my car idle warm like when I forget something in the house and the car is on. Recently, I couldn't find my cell phone and my car sat idling for 10 minutes and the temp gauge was at 25%. THAT RIGHT THERE TELLS ME THAT DRIVING THE CAR RIGHT AWAY WARMS IT UP MUCH QUICKER.
To everyone who lives in a cold climate, try this. If it doesn't work, then you can tell me to go **** off. If it does work, I told you so.
One morning, let your car idle warm up and record how long it takes to get to the mid point on the temp gauge. The next morning, start your car and let it run for 30 seconds and then start driving. Record how long it takes to warm up. DON'T use your heater right away either. Turn it on when the gauge get close to the mid point. I am almost positive yor car will be warm in 2-3 minutes.
Dave
Chebosto-
I live in Kansas City and the highs for the past 2 weeks have been in the teens and lows in the 5-10 below range. Hell, the snow on my car doesn't even melt in my garage. All my beer froze in my garage too!!!!
Anyways, my car is warmed up to the halfway mark after driving at 2500 rpms in 2nd gear for less than a mile. That means it takes approximately 2 minutes for my car to get into a nice operating temp plus my heater is working in 2 minutes. That means I'm driving in a ice box of a car for 2 minutes. I'd much rather do it this way then let my car sit there and idle to warm up. There have been times where I have had to let my car idle warm like when I forget something in the house and the car is on. Recently, I couldn't find my cell phone and my car sat idling for 10 minutes and the temp gauge was at 25%. THAT RIGHT THERE TELLS ME THAT DRIVING THE CAR RIGHT AWAY WARMS IT UP MUCH QUICKER.
To everyone who lives in a cold climate, try this. If it doesn't work, then you can tell me to go **** off. If it does work, I told you so.
One morning, let your car idle warm up and record how long it takes to get to the mid point on the temp gauge. The next morning, start your car and let it run for 30 seconds and then start driving. Record how long it takes to warm up. DON'T use your heater right away either. Turn it on when the gauge get close to the mid point. I am almost positive yor car will be warm in 2-3 minutes.
Dave
12-20-2000, 01:36 PM
#50
Not DAVEB the parts guy
Thread Starter
Join Date: Aug 2000
Posts: 8,555
Tom-
You are right. The issue here is which is better for a car. What is best for a car is to get the motor up to temp as fast and safely as possible. By idle warming the car it takes far longer than just starting it and driving nearly right away. I'm not saying you should start the car and immediately run a WOT 1/4 mile blast. Instead, just drive like normal and shift nicely. We all know a nice and warm motor is in near peak efficency. Why would you want your car to sit there a idle away and warm up slowly? It makes no sense to me.
If warming up the engine as soon as possible didn't matter, then automakers wouldn't employ thermostats to regulate coolant flow? On start up, the thermostat stays shut and keeps the coolant from flowing until the engine reaches a certain temp (usually 180 degrees).
Dave
[Edited by Dave B on 12-20-2000 at 03:41 PM]
You are right. The issue here is which is better for a car. What is best for a car is to get the motor up to temp as fast and safely as possible. By idle warming the car it takes far longer than just starting it and driving nearly right away. I'm not saying you should start the car and immediately run a WOT 1/4 mile blast. Instead, just drive like normal and shift nicely. We all know a nice and warm motor is in near peak efficency. Why would you want your car to sit there a idle away and warm up slowly? It makes no sense to me.
If warming up the engine as soon as possible didn't matter, then automakers wouldn't employ thermostats to regulate coolant flow? On start up, the thermostat stays shut and keeps the coolant from flowing until the engine reaches a certain temp (usually 180 degrees).
Dave
[Edited by Dave B on 12-20-2000 at 03:41 PM]
12-20-2000, 08:10 PM
#51
Senior Member
Join Date: Sep 2000
Posts: 422
not convinced
I lived in Alberta for 5 years where temperatures often hit the minus 20 Fahrenheit mark.Ever have flat spots on your tires in the morning??? People would at times let their cars idle for hours on end because turning them off could mean not being able to re-start them at all. The more than a dozen cars I have owned over the years, all averaged 2o minutes of start up time in the winter, including my current Maxima. Not only would you have to stop every few minutes to re-scrape the outside of your windshield if you drove off right away, the INSIDE also fogs and freezes and requires scraping if the windshield isnt totally warm. So why be unsafe and stupid?? who wants to feel like they are back in a 1967 Beetle??? None of my cars ever had any engine problems at the time I sold them, which was usually after about 200,000 miles.If it's such a big worry for you..why dont you just install a block heater?? It's amazing how quickly that will warm up an engine, and in turn the interior.
I think we need to consult with some Swedes and Norwegians on this topic. Think I'll e-mail Volvo. I'm sure Sven will know the answer to this one!
I think we need to consult with some Swedes and Norwegians on this topic. Think I'll e-mail Volvo. I'm sure Sven will know the answer to this one!
12-21-2000, 07:04 AM
#54
Senior Member
Join Date: Nov 2000
Posts: 915
We all know what the manual says.
the debate here, is on whether or not that 30 secs is a minimum (ie.. warming up the car longer = better)..
OR
does warming up (idling) the car past the 30 secs cause damage??
OR
does it do neither.... no damage, no gain.. just wasted gas..
-Tom
the debate here, is on whether or not that 30 secs is a minimum (ie.. warming up the car longer = better)..
OR
does warming up (idling) the car past the 30 secs cause damage??
OR
does it do neither.... no damage, no gain.. just wasted gas..
-Tom
Originally posted by Pmp-n8a
Yah...just read your manual...says to warm it up for 30 seconds...derf
Yah...just read your manual...says to warm it up for 30 seconds...derf
12-21-2000, 08:24 AM
#55
Senior Member
Join Date: Sep 2000
Posts: 1,308
Originally posted by Dave B
Jim-
By operating a motor from idle to 4000rpms nearly all of it's life and has redline of 6500 rpms will mostly result in a quick failure of the gaskets if you start running it above 4000. WHy? Because the gaskets are not used to increased pressure of operating the motor at such high rpms therefore they fail and leak (or blow). I think you do more damage to your transmission by shifting it hard at a high rpm when racing then you do damage to the motor revving it high (not exceeding redline).
Dave
Jim-
By operating a motor from idle to 4000rpms nearly all of it's life and has redline of 6500 rpms will mostly result in a quick failure of the gaskets if you start running it above 4000. WHy? Because the gaskets are not used to increased pressure of operating the motor at such high rpms therefore they fail and leak (or blow). I think you do more damage to your transmission by shifting it hard at a high rpm when racing then you do damage to the motor revving it high (not exceeding redline).
Dave
10-17-2001, 06:53 PM
#56
Guest
Posts: n/a
Why would setting the defrost on cold warm get the ice off faster than setting it on hot?
Also, my car won't fully warm up all the way if I just let it sit there and idle, I have to drive it to get it up to the half point. It also takes significantly less time if I simply drive off.
Also, my car won't fully warm up all the way if I just let it sit there and idle, I have to drive it to get it up to the half point. It also takes significantly less time if I simply drive off.
10-17-2001, 08:45 PM
#58
Originally posted by MaxedOut97SE
Why would setting the defrost on cold warm get the ice off faster than setting it on hot?
Also, my car won't fully warm up all the way if I just let it sit there and idle, I have to drive it to get it up to the half point. It also takes significantly less time if I simply drive off.
Why would setting the defrost on cold warm get the ice off faster than setting it on hot?
Also, my car won't fully warm up all the way if I just let it sit there and idle, I have to drive it to get it up to the half point. It also takes significantly less time if I simply drive off.
, oh well its winter again.
10-17-2001, 11:39 PM
#61
Ohh nuh uh??? i didn't notice it was a dead thread til now...
i always idle start my car in the mornings,, every morning til the temp needle hits midway.. wah.. dunno i've heard about not letting it ilde, as well as let it idle til it's at "normal operating temp"
i always idle start my car in the mornings,, every morning til the temp needle hits midway.. wah.. dunno i've heard about not letting it ilde, as well as let it idle til it's at "normal operating temp"
10-18-2001, 06:12 AM
#62
Member who somehow became The President of The SE-L Club
iTrader: (19)
Join Date: Jun 2001
Posts: 16,033
Dave, I can agree with most of what you wrote. However your statement about "oil pooling" is by far false. You have 60 - 80 pounds of oil pressure with a cold engine. Believe me it pumps just as good at cold idle as it does when the engine is hot and idling. Actually there should be slightly MORE oil pressure when the car is cold because the oil is slightly thicker.
Engines are designed with sophisticated lubricating systems which keep the entire engine lubricated during all periods of operation. That includes cold and hot engine operation.
There are however a few disadvantages of letting you car idle for long periods of time. A few of which you did mention.
If you wish to warm up your car prior to operation, then by all means do so. Your not doing any harm to your motor. As well if you wish to just "start and go", then keep in mind you should take it easy for the first few minutes of operation. Allow the engine to completely warm to normal operating temperature before you drive it hard, this way your sure not to blow a head gasket!
Engines are designed with sophisticated lubricating systems which keep the entire engine lubricated during all periods of operation. That includes cold and hot engine operation.
There are however a few disadvantages of letting you car idle for long periods of time. A few of which you did mention.
If you wish to warm up your car prior to operation, then by all means do so. Your not doing any harm to your motor. As well if you wish to just "start and go", then keep in mind you should take it easy for the first few minutes of operation. Allow the engine to completely warm to normal operating temperature before you drive it hard, this way your sure not to blow a head gasket!
10-18-2001, 08:51 PM
#66
Senior Member
Join Date: Sep 2000
Posts: 1,308
Originally posted by njmaxseltd
Dave, I can agree with most of what you wrote. However your statement about "oil pooling" is by far false. You have 60 - 80 pounds of oil pressure with a cold engine. Believe me it pumps just as good at cold idle as it does when the engine is hot and idling. Actually there should be slightly MORE oil pressure when the car is cold because the oil is slightly thicker.
Engines are designed with sophisticated lubricating systems which keep the entire engine lubricated during all periods of operation. That includes cold and hot engine operation.
There are however a few disadvantages of letting you car idle for long periods of time. A few of which you did mention.
If you wish to warm up your car prior to operation, then by all means do so. Your not doing any harm to your motor. As well if you wish to just "start and go", then keep in mind you should take it easy for the first few minutes of operation. Allow the engine to completely warm to normal operating temperature before you drive it hard, this way your sure not to blow a head gasket!
Dave, I can agree with most of what you wrote. However your statement about "oil pooling" is by far false. You have 60 - 80 pounds of oil pressure with a cold engine. Believe me it pumps just as good at cold idle as it does when the engine is hot and idling. Actually there should be slightly MORE oil pressure when the car is cold because the oil is slightly thicker.
Engines are designed with sophisticated lubricating systems which keep the entire engine lubricated during all periods of operation. That includes cold and hot engine operation.
There are however a few disadvantages of letting you car idle for long periods of time. A few of which you did mention.
If you wish to warm up your car prior to operation, then by all means do so. Your not doing any harm to your motor. As well if you wish to just "start and go", then keep in mind you should take it easy for the first few minutes of operation. Allow the engine to completely warm to normal operating temperature before you drive it hard, this way your sure not to blow a head gasket!
10-19-2001, 06:28 AM
#67
Member who somehow became The President of The SE-L Club
iTrader: (19)
Join Date: Jun 2001
Posts: 16,033
Originally posted by VQdriver
when i'm at the track, sometimes the car sits for an hour and half or so between runs. i also ice the intake manifold with an 8 lb bag of ice. when i start up, the car's temp guage is at the 1/4 mark. i want to know if icing or letting it rest for long periods to let it cool hurts the engine in any way. i mean the engine does retain a lot of heat, but the temp guage has fallen to just a tad above the cold mark.
when i'm at the track, sometimes the car sits for an hour and half or so between runs. i also ice the intake manifold with an 8 lb bag of ice. when i start up, the car's temp guage is at the 1/4 mark. i want to know if icing or letting it rest for long periods to let it cool hurts the engine in any way. i mean the engine does retain a lot of heat, but the temp guage has fallen to just a tad above the cold mark.
10-19-2001, 02:22 PM
#68
You're Faster, I'm Better
Join Date: Jul 2001
Posts: 512
Originally posted by mrb23
Man, I've never warmed up my car. Not even for 15 seconds. It does feel a bit sluggish but only for like 2 minutes. The old Datsun I had was never warmed up either and that car lasted about 100k before it was sold
Man, I've never warmed up my car. Not even for 15 seconds. It does feel a bit sluggish but only for like 2 minutes. The old Datsun I had was never warmed up either and that car lasted about 100k before it was sold
10-19-2001, 02:37 PM
#69
I respect Dave and all but there are two things that don't make sense.
1) Letting it idle will cause a gas smell in the oil. If there was enough gas in the oil to make it smell like gas, there would be a very serious problem. I really doubt extended idling would allow that much(if any at all) gas into the oil.
2) It takes 45 min to burn the gas out of the oil. Again doesn't make sense. Since IMHO 90% of people's drives are less than 45 min. That would indicate a whole lot of people w/ excessive gas in their oil and alot of ruined engines. I don't see how you can burn off just the gas portion of the oil/gas mixture.
I think he might have a valid concern if were talking about a 1960's vintage car w/ manual/electric chokes and carburators but with today's modern engine mangement and strict emission controls.
1) Letting it idle will cause a gas smell in the oil. If there was enough gas in the oil to make it smell like gas, there would be a very serious problem. I really doubt extended idling would allow that much(if any at all) gas into the oil.
2) It takes 45 min to burn the gas out of the oil. Again doesn't make sense. Since IMHO 90% of people's drives are less than 45 min. That would indicate a whole lot of people w/ excessive gas in their oil and alot of ruined engines. I don't see how you can burn off just the gas portion of the oil/gas mixture.
I think he might have a valid concern if were talking about a 1960's vintage car w/ manual/electric chokes and carburators but with today's modern engine mangement and strict emission controls.
10-19-2001, 04:06 PM
#70
Senior Member
Join Date: Aug 2000
Posts: 1,081
crap!!!!!!!!
Originally posted by Dave B
It seems that nearly every "non-car" person and even soon people in this forum think that the best way to warm up a car in the winter is to let it idle for 5-20 minutes. If these people only knew the damage they are doing to their motors. None seem to believe me when I tell them what happens by doing this poorly choosen warm up procedure. By letting a cold motor idle for a length of time, the oil does not circulate throughout the whole motor. Instead, it mostly "pools" around the lower half of the motor therefore increasing wear along cams and such. On a cold engine start up and under normal running temps, the ECU is running a very rich fuel program to make the engine warm up as fast possible. What does this mean for the motor? It means A LOT of fuel isn't getting burned and is seeping into the oil and degrading it quickly. Also, the rich exhaust will eventually foul the cat.
People just don't understand that you should start driving a cold car as soon as the oil pressure gets into the normal range which is about 30-60 seconds after start up. It sounds hard on a cold engine to begin driving nearly right away after starting it, but it isn't true. It is far less strenuous on the motor to warm up under load (ie driving). Why? Because the oil circulates better, the fuel program becomes leaner, and the increased tranny heat begins to help warm up the motor.
Why does this worry me? Because I will always buy used cars and you never know if the prior owner was misinformed about warming up a motor.
Dave
It seems that nearly every "non-car" person and even soon people in this forum think that the best way to warm up a car in the winter is to let it idle for 5-20 minutes. If these people only knew the damage they are doing to their motors. None seem to believe me when I tell them what happens by doing this poorly choosen warm up procedure. By letting a cold motor idle for a length of time, the oil does not circulate throughout the whole motor. Instead, it mostly "pools" around the lower half of the motor therefore increasing wear along cams and such. On a cold engine start up and under normal running temps, the ECU is running a very rich fuel program to make the engine warm up as fast possible. What does this mean for the motor? It means A LOT of fuel isn't getting burned and is seeping into the oil and degrading it quickly. Also, the rich exhaust will eventually foul the cat.
People just don't understand that you should start driving a cold car as soon as the oil pressure gets into the normal range which is about 30-60 seconds after start up. It sounds hard on a cold engine to begin driving nearly right away after starting it, but it isn't true. It is far less strenuous on the motor to warm up under load (ie driving). Why? Because the oil circulates better, the fuel program becomes leaner, and the increased tranny heat begins to help warm up the motor.
Why does this worry me? Because I will always buy used cars and you never know if the prior owner was misinformed about warming up a motor.
Dave
ANyway DaveB... how much you sell that DUm DUM sealant for the tailights for?
Roger
10-19-2001, 04:37 PM
#71
Senior Member
Join Date: Sep 2001
Posts: 788
Originally posted by deathwish
Well, here's what I do...
First, you gotta put on some soothing music. None of that limp bizkit crap, maybe some sinatra or something from the big band era. Now, casually start to give her a little rub on the trunk. She's had a rough night, just loosen her up a little bit. Work your way around a bit, then slip off her car cover and get a little warm carnuba wax and start to massage it in. Pay special attention to her meaty areas, the fenders, A-pillars, etc. Light some scented candles. After a little of this, she'll be plenty warmed up and putty in your hands.
Well, here's what I do...
First, you gotta put on some soothing music. None of that limp bizkit crap, maybe some sinatra or something from the big band era. Now, casually start to give her a little rub on the trunk. She's had a rough night, just loosen her up a little bit. Work your way around a bit, then slip off her car cover and get a little warm carnuba wax and start to massage it in. Pay special attention to her meaty areas, the fenders, A-pillars, etc. Light some scented candles. After a little of this, she'll be plenty warmed up and putty in your hands.
Mmmmmm.... I'm sorry...
What were you all talking about???
ADMAN
10-19-2001, 04:38 PM
#72
Senior Member
Join Date: Sep 2001
Posts: 788
Originally posted by WoodEar
Yeah i realized afterwars it's beat beat beaten, but too lazy too edit.
hey, that's one good thing about being asian(non-abc) in us, you have to excuse my freaking spelling!
Yeah i realized afterwars it's beat beat beaten, but too lazy too edit.
hey, that's one good thing about being asian(non-abc) in us, you have to excuse my freaking spelling!
There he goes...one notch lower again!!!
ADMAN
10-19-2001, 04:41 PM
#73
Senior Member
Join Date: Sep 2001
Posts: 788
Re: Well let me throw this in......
Originally posted by Mike S.
from someone who not only lives in a cold are but gets lots of snow....BUFFALO, NEW YORK!
On a cold snowy day....do you think people are gonna clear off their cars(up to 5 min) and THEN start up? NO....they start em up and then clear them off. Are they all doing damage? Well i guess so. If they are doing damage i don't think you'd see it in less than 200K. We ALL do this around here.....there are just as many high mile cars running around. I wouldn't sweat it. Plus I use Mobil 1
Mike S.
from someone who not only lives in a cold are but gets lots of snow....BUFFALO, NEW YORK!
On a cold snowy day....do you think people are gonna clear off their cars(up to 5 min) and THEN start up? NO....they start em up and then clear them off. Are they all doing damage? Well i guess so. If they are doing damage i don't think you'd see it in less than 200K. We ALL do this around here.....there are just as many high mile cars running around. I wouldn't sweat it. Plus I use Mobil 1
Mike S.
Lots of snow???
WHAT'S THAT????
ADMAN
10-19-2001, 05:58 PM
#74
Senior Member
Join Date: Mar 2001
Posts: 200
ouch
Respectfully, I think your information is totally wrong.
The reason a 5-20 minute warm-up is not recommended is that it's a waste of fuel. It's not necessary, just as break-in is not necessary. You don't damage a motor by warming it up, you simply waste fuel unnecessarily. If you can stand the cold, then drive it asap easily.
In Alaska, people do warm up their vehicles, and they do not shut them down. Getting into a cold car then becomes a safety issue, because at -45 F, moisture instantly freezes to the front windshield, and it cannot be cut by the a/c, and that is a safety problem. It needs heat to remain clear.
This notion of fuel mixing with the motor oil comes from the old 1/2/4-barrel carburetor, where if a motor were floored during acceleration fuel would wash down the sides of the crankcase. But they went the way of the dinosaur sometime in the early 80's.
I totally agree that misconceptions are incredible. Kinda like the one that if you don't change your oil every 3k the car turns into a pumpkin. I have a coworker who does Mobil 1 every 2.5k. Talk about money being wasted.
The reason a 5-20 minute warm-up is not recommended is that it's a waste of fuel. It's not necessary, just as break-in is not necessary. You don't damage a motor by warming it up, you simply waste fuel unnecessarily. If you can stand the cold, then drive it asap easily.
In Alaska, people do warm up their vehicles, and they do not shut them down. Getting into a cold car then becomes a safety issue, because at -45 F, moisture instantly freezes to the front windshield, and it cannot be cut by the a/c, and that is a safety problem. It needs heat to remain clear.
This notion of fuel mixing with the motor oil comes from the old 1/2/4-barrel carburetor, where if a motor were floored during acceleration fuel would wash down the sides of the crankcase. But they went the way of the dinosaur sometime in the early 80's.
I totally agree that misconceptions are incredible. Kinda like the one that if you don't change your oil every 3k the car turns into a pumpkin. I have a coworker who does Mobil 1 every 2.5k. Talk about money being wasted.
10-19-2001, 09:23 PM
#76
Senior Member
Join Date: May 2001
Posts: 1,591
Originally posted by Dave B
It seems that nearly every "non-car" person and even soon people in this forum think that the best way to warm up a car in the winter is to let it idle for 5-20 minutes. If these people only knew the damage they are doing to their motors. None seem to believe me when I tell them what happens by doing this poorly choosen warm up procedure. By letting a cold motor idle for a length of time, the oil does not circulate throughout the whole motor. Instead, it mostly "pools" around the lower half of the motor therefore increasing wear along cams and such. On a cold engine start up and under normal running temps, the ECU is running a very rich fuel program to make the engine warm up as fast possible. What does this mean for the motor? It means A LOT of fuel isn't getting burned and is seeping into the oil and degrading it quickly. Also, the rich exhaust will eventually foul the cat.
People just don't understand that you should start driving a cold car as soon as the oil pressure gets into the normal range which is about 30-60 seconds after start up. It sounds hard on a cold engine to begin driving nearly right away after starting it, but it isn't true. It is far less strenuous on the motor to warm up under load (ie driving). Why? Because the oil circulates better, the fuel program becomes leaner, and the increased tranny heat begins to help warm up the motor.
Why does this worry me? Because I will always buy used cars and you never know if the prior owner was misinformed about warming up a motor.
Dave
It seems that nearly every "non-car" person and even soon people in this forum think that the best way to warm up a car in the winter is to let it idle for 5-20 minutes. If these people only knew the damage they are doing to their motors. None seem to believe me when I tell them what happens by doing this poorly choosen warm up procedure. By letting a cold motor idle for a length of time, the oil does not circulate throughout the whole motor. Instead, it mostly "pools" around the lower half of the motor therefore increasing wear along cams and such. On a cold engine start up and under normal running temps, the ECU is running a very rich fuel program to make the engine warm up as fast possible. What does this mean for the motor? It means A LOT of fuel isn't getting burned and is seeping into the oil and degrading it quickly. Also, the rich exhaust will eventually foul the cat.
People just don't understand that you should start driving a cold car as soon as the oil pressure gets into the normal range which is about 30-60 seconds after start up. It sounds hard on a cold engine to begin driving nearly right away after starting it, but it isn't true. It is far less strenuous on the motor to warm up under load (ie driving). Why? Because the oil circulates better, the fuel program becomes leaner, and the increased tranny heat begins to help warm up the motor.
Why does this worry me? Because I will always buy used cars and you never know if the prior owner was misinformed about warming up a motor.
Dave
VOOomm
M POWER
10-23-2001, 04:05 AM
#77
Senior Member
Join Date: Mar 2001
Posts: 172
Warm up? What's that?!
Seriously though, all the cars in my family have never been warmed up, not even for 15 seconds. They've all been quite healthy till they were gotten rid of, some were in use daily for 12+ years.
I get in the car, buckle up, do anything else I want to do to prep.. THEN start the car and go! I don't rev hard till the engine is warm though. Just drive it easy.
This is in line with what my driver's manual says, and any recent automotive repair manual, or publication.. I've never heard from a credible source that idling your engine to warm it hurts it, but damn, that's a waste of gas.
At $2/gal, I prefer not to waste it. Of course, I don't have to deal with subzero temperatures (about 40F is the lowest).
Seriously though, all the cars in my family have never been warmed up, not even for 15 seconds. They've all been quite healthy till they were gotten rid of, some were in use daily for 12+ years.
I get in the car, buckle up, do anything else I want to do to prep.. THEN start the car and go! I don't rev hard till the engine is warm though. Just drive it easy.
This is in line with what my driver's manual says, and any recent automotive repair manual, or publication.. I've never heard from a credible source that idling your engine to warm it hurts it, but damn, that's a waste of gas.
At $2/gal, I prefer not to waste it. Of course, I don't have to deal with subzero temperatures (about 40F is the lowest).
10-23-2001, 03:05 PM
#79
Member
Join Date: Sep 2001
Location: Monmouth County,New Jersey
Posts: 260
Re: daymn
Originally posted by VQracer
ive been warming up my bike like that
ive been warming up my bike like that
10-23-2001, 04:54 PM
#80
My .02
DaveB is on the right track, it IS better to drive the car easily to warm it up, but not doing this will not HURT the engine, it's just not as good for it. The reason is that there are many different metals in the engine that heat up and expand at different rates. For example, a piston would be made of a different metal than the block. If the piston expands faster than the block (we are talking microscopic differences) it will exert more force on the sidewall thus creating more wear. This is why it's better to drive the car, the metals will warm up to operating tolerances faster. I'm not saying drive it hard, though. It is bad to pull a lot of power from a cold engine, it's a compromise to warm it up quickly, but not too quickly.
To the guy in AK, the difference in leaving the car running is that it's already warmed up, so wear is almost non-existent.
To Jeff92SE: Small amounts of fuel and other byproducts of combustion do leak past the rings and need time to "burn off" from the oil and it can take a long time. The term "burn off" can be misleading. It's more like the contaminants simmer over time and are vented out breathers from the crankcase. It's kinda like a crockpot. This is why manufacturers have a severe service schedule for cars that do lots of short trips. These contaminants don't have time to "burn off" and saturate the oil faster than in a car that is driven on the highway more.
I hope this makes some sense to people.
DaveB is on the right track, it IS better to drive the car easily to warm it up, but not doing this will not HURT the engine, it's just not as good for it. The reason is that there are many different metals in the engine that heat up and expand at different rates. For example, a piston would be made of a different metal than the block. If the piston expands faster than the block (we are talking microscopic differences) it will exert more force on the sidewall thus creating more wear. This is why it's better to drive the car, the metals will warm up to operating tolerances faster. I'm not saying drive it hard, though. It is bad to pull a lot of power from a cold engine, it's a compromise to warm it up quickly, but not too quickly.
To the guy in AK, the difference in leaving the car running is that it's already warmed up, so wear is almost non-existent.
To Jeff92SE: Small amounts of fuel and other byproducts of combustion do leak past the rings and need time to "burn off" from the oil and it can take a long time. The term "burn off" can be misleading. It's more like the contaminants simmer over time and are vented out breathers from the crankcase. It's kinda like a crockpot. This is why manufacturers have a severe service schedule for cars that do lots of short trips. These contaminants don't have time to "burn off" and saturate the oil faster than in a car that is driven on the highway more.
I hope this makes some sense to people.