suds1

I did a search on this and didn't find anything that really answered my question.

I'm thinking of changing to Synthetic Oil (Mobil 1) on my next oil change. What weight should I use? I've always used 10W-30 in regular oil.

Also how often do y'all change your oil when running synthetic?

Is there anything specific I need to do before switching to synthetic of do I just drain the old stuff and change the filter as usual before adding the synthetic?

karguy

When I switched my 97 to Synthetic Oil (45,000 miles) I used an engine flush from AMSOIL. They recommended it be done before switching to Synthetic oil from dino oil! Also a lot of info has been posted on Mobile 1's new formulation. You might want to do a search and read the posts.

Highlander

My 2000 owner's manual says 5W30 is the correct weight. 10W30 is probably OK as well, especially if you live somewhere warm. Depending on the synthetic used, you can possibly get much longer drain intervals - Amsoil makes one up to 35,000/1year. You'll definitely want to do an engine flush before switching - it's pretty easy to do - which will clear out the crap left behind by dino.

IceY2K1

iTrader: (3)

Do NOT use a 5W-30 unless you live in an area with EXTREME cold weather(i.e. Canada). Manufacturers are saying that to eek out the maximum fuel economy possible and reduce emissions, but it increases engine wear especially in high shear conditions such as the bearings and cylinder walls.

A 10W-30 or a 10W-40 is MUCH better for engine durability by providing a thicker oil film at operating temperature.

wdave

Normally, you would use the same weight synthetic as conventional oil. The reason the manual recommends 5w30 if it gets cold where you are is so the oil pumps around more quickly on cold starts, synthetic does that better anyway. If you don't have a lot of mileage and your engine is reasonably clean inside there's no need to flush. However, be aware that there will be some of whatever was in your engine (dino oil or flush) along with your first load of synthetic so it is a good idea to make the first change interval a little shorter. I personally go 6-7 k on Mobil 1 (max warranty interval is 7500), I suspect you could go longer with a filter change.

wdave

Old wives' tale. 30 is the operating weight, 5 or 10 is the cold weight. Manufacturers specify 30 (or even 20 on new Hondas) instead of 40 for fuel economy. They specify 5 instead of 10 for quicker oil pressure (and protection) on cold starts, when most wear occurs.

Colonel

Allllex,

Gonna have to disagree with ya here. Read some of the testing done on film strength at op temp of oils. The larger the spread typically the less "tear" strength that the oil film will have. But as I have been noticing as the technology moves on...the better it has gotten.

But the 5W will give you better startup circulation and protection than a 10W. Which if you live in loser city in Arizona where it never gets cold, it might not be a problem. But if you live farther North, say a loser city in Ohio, it should be a consideration whether to use 5W or 10W.

My wifes new 2002 Ford Focus actually recommends 5W-20...I was like WTF? You CAN run 10w-40 or 10W-30 in these cars...As for it being the BEST option...I think only test results from identical cars running the different grades (10W vs 5W) is gonna really show what is "best" and you always have to consider outside temp operating range as well.

bill99gxe

iTrader: (1)

http://forums.maxima.org/showthread....hreadid=100060

TimW

iTrader: (6)

and my oil reports show less than average wear.

I stayed at 5W for startup protection because the VQ always runs up to 2000 RPM when it fires. I hate that..

BuddyWh

I think he is right (about avoiding 5w-30), maybe for the wrong reason though...

The property of oils that make for wide multi-viscosity ranges is a polymer that is added to the oil... at cool temps, the polymer molecule is coiled up. It uncoils at higher temp's, counteracting the thinning of the base oil. Wide-range multi-vis oils have more of these polymers added.

The problem with the polymer molecules is they break down quickly, leading to engine deposits, sludge, varnish. The rule of thumb is to stay within a 20-"point" spread; 10w30, 20w40 are OK; 20w50 and 5w30 are risky and shouldn't be used except in special situations.

Polymer viscosity extenders are used even with synthetic oils. If you are pushing for long drain intervals then it sure seems to me you want to stay away from wide range multi-vis. In fact, given their inherently excellent low temp pour points, I'd try to stay with a single weight and completely avoid the problem altogether. That's why you are using synthetic, why not take full advantage of it's properties.

BuddyWh

johnny2kgle

As mentioned before, do a flush with the Amsoil product. Stay away from Mobil 1 since the formulation has changed for the worst. I personally use Amsoil 5w30. If you must buy off the shelf, get the Valvoline product.

As for conventional oil, 5w-30 is horrible in a warm climate like Georgia or Arizona. The stuff is so full of destabilizers to flow at low temperature, that it evaporates and combusts. I burned over .5 quart in less than 3000 miles and that was in the dead of winter. If you stay with dino juice, 10w-30 year round is preferred down south.

enicemax

I work for Castrol North America, in the R&D dept (chem engineer). Here are the facts: 5W and 10W (and even 0W) really dont come into play whatsoever unless ur dealing with extreme weather/temp conditions (for example, u live in Alaska/Phoenix). As for the the weight, its exactly true that manufacturers recommend lower weights for one reason only; that is to make claims about fuel efficiency and gas-mileage. They'll recommend the lowest-possible grade that they're allowed. Higher weight oil, when used in normal operating temps (which is most of America), provides better engine-wear protection, with the tradeoff of not so great gas-mileage. I've used 10-40, 5-40, and even 5-50 in my car so far (2002 with 12K), and they're all fine. These are the facts, straight from Castrol engineers and scientists who have no bias (at least not on the job), so take it as you will.

Jeff92se

iTrader: (82)

I assume this is for dino based oil or for all oil(including synthetics)?

Even if you use a lower viscosity oil for the cold weight(ie.. 5w), a quality oil like Amsoil has many times the film strength as compared to dino oil. This also goes for the operating temp oil(ie.. using 30w vs 40w). So an Amsoil 5w-30 will probably protect much better than any dino 10w-40 at operating temp just because by nature, synthetics are so much better.

But I do agree 100% that the 0w or even a 5w will not do much (or anything) if the ambinent temps to drop below 40 deg F or so.

enicemax

Its for all oils, but synthetics provide a much greater (incomparably greater) level of protection than conventional oil because of the chemistry of the blend and the process in which the base stock is processed from crude. Synthetic oils are engineered with detergents, rust-inhibitors, anti-wear agents and othe additives to produce a far superior oil. Moreover, synthteics withstand the widest range of temperature conditions. They wont breakdown or oxidize at high temps like conventional oil does. They don't thicken the way conventional oil does at low temps (even up to -30F and below), which provides for better cold starts (making 5W and 10W not as important factors anymore). I won't get into too much chemistry talk in here, but if you have any specific questions, just ask me.

CHAZMAX

enicemax,
Well, since you offered.... and you seem to really know what you're talkin about.

I've never really gotten a straight answer for this:

I live in Houston, Tx. Hot temperatures and consistent traffic. 2K2 Auto, 30-45 minute trips to work.

What weight (of Mobile One) would YOU recommend for me?

I currently run Mobile One 5w-30.

Thx in advance!

BuddyWh

Should you not operate ONLY what your manual requires? Are you interested in assuring warranty coverage?

Buddywh

enicemax

Well, engines that are lubricated with low viscosity oil are more susceptible to volatility burn off at higher temps (the base oils in conventional oils volatilize or evaporate, resulting in harmful deposits and an engine running low on oil). Synthetic oil greatly reduces this burnoff. So, just using synthetic oil is a must at higher temps, and furthermore, I would say use 40 weight (or if its really hot 50; use 5 or 10, but i would lean towards 10). Like I said, gas mileage may be affected (not by much tho), but thats the tradeoff you pay for maximum engine protection. In the long run, it pays dividends. There are so many things you will save from going wrong by maintaining your car with quality oil. Also, I wouldn't recommend that you go alot more without oil-changes than with conventional, just for the fact that the oil still gets dirty, and the filter especially needs to be changed.

BuddyWh

While most of what I have read agrees with you (and your engineers) about the bias of auto manufacturers towards lighter weights, almost everybody else agrees that wide-range multi-vis is bad. You should avoid it... in my estimation you're lucky you have driven only 12k on 5-50 and 5-40. I hope you follow a regime of frequent oil changes (so many weights in that short a time, sounds like you do).

It has nothing to do with engine wear protection, it is strictly build up of sludge, gum, varnishes. With my '94 Rodeo, it is a common problem for people who've run 10-40 and 20-50 to have the lifter's oiling ports clog... the manufacturer's recommendation is a VERY STRONG 10-30, straight 30 weight preferred. Isuzu has a TSB covering the problem (famous among Isuzu fans... kind of like the throttle cut TSB for the Max). It is a very common problem and leads to lifter noise... sounds like a diesel when idling.

If you want to run a heavier weight oil, just use one that doesn't have such a wide multi-vis range. Select carefully for your driving conditions... I can't imagine any normal user that operates at the extremes of -20 to +110 in a reasonable period of time.

But if using synthetic, why not take maximum advantage of it and use a straight 30 weight? A fairly low viscosity for good gas mileage, and yet provides excellent wear protection all the way to 110+F.

BuddyWh

CHAZMAX

Once again... Thx.

enicemax

Trust me, I do know what I'm talkin about. Your comments about multi-vis aren't that accurate, and i'm not tryin to flame you. I've kinda got a little more inside info on this subject, and more objective info from people who've been in the industry for a long time. The engineers here are extremely smart, and know what they're talkin about, since they're involved in formulating oils for top car makers (i.e., BMW, Chrysler, Ford) and also for racing teams (NHRA, NASCAR). I'm speaking strictly scientifically, no opinions from myself. That wide range multi-vis u'r speaking of really has no bearing.

Highlander

WOW... Maybe we need an oil FORUM?

BuddyWh

Ok... I'd like to... but how when every article I've read are so consistent in their cautions and suggestions concerning multi's? And these are very knowledgeable people with years of experience in many facets of the industry... racing, oil, consumer (Consumer's Union, specificaly.) And automobile manufacturers (BMW for one)... I've read where some have threatend to void warranties if 10-40 is used.

But I do have to keep in mind that none say wide-range multi's are pure garbage... just that they have a very special purpose and should be used wisely for those purposes.

Even Amsoil uses polymer viscosity extenders for their wide-range oils and some people are talking using an Amsoil "charge" for 20K miles, up to 30K. I think that if you are making that kind of commitment to your oil, you should make the best choice possible, and should be made aware of the concerns many industry experts have voiced concerning wide-range multi vis. Then it is, as always, your choice.

Sorry, but it's hard to give up that kind of background very easily.

BuddyWh

Jeff92se

iTrader: (82)

I kinda have to agree with Buddy. Everything I've read on the subject points to the fast that high differences in viscosities are difficult to maintain. If you don't need that high of viscosity change, I would steer away from it. I've read that to maintain high viscosity differentials, you must add alot of additives. And it's these additives that start to break down and turn into whatever as the oil ages. But more importantly, the breakdown of these additives mean your oil slowly turns into something other than the 10w-40 orginally poured in.

I'm not sure but if you are that concerned about keeping the metals in your engine from touching each other, you should be more concerned about the oil's film strength vs the viscosity rating IMHO.

If our newer member does have the extensive background, we need to see some info to update us. Just saying you are xxxx person is nice, but doesn't help us. Give us some links for us to evaluate. Makes our knowledge of oil advance slower but at least it advances correctly.

suds1

Wow. Now I'm more confused than I was when I started this thread.

I think I'll just stick to the Pennzoil 10W-30 I've been using. Its worked pretty well for the first 60,000 miles anyway.

Thanks for all your input though.

enicemax

I dont have links to direct u to; i know specifically the additive chemistry in Castrol Syntec, which I suspect isn't too different from other oil-makers. I can't divulge that informatin tho, since it would compromise the company's policy. You can be assured tho that I'm speaking with the backing of extremely knowledgeable engineers and scientists who I work with. I'm talkin about developers of the oil, who use what I was referring to in their own cars. Maybe u'r getting the wrong message from what I'm saying about viscosity, oil weight, and things like that. I think u'r statements are more founded if u'r speaking about conventional oil. I dont know of any links with info on the subject. But, listen to this example: One of the chief senior mechanical/chemical engineers who works in the company (who is also a car connoiseur with a 65 corvette in mint condition) directed me to use 5-50 (syntec) in the car, and said it would have no adverse effects whatsoever, save some decrease in gas-mileage. He himself said he'd put nothing lower than 40 weight oil in his car (5 or 10W40). Obviously, if there were anything even minimally wrong with this he would most surely know about it. I think you need to concede that maybe your information isn't as up to date as mine. I'm not being condescending or anything, just saying that my information is completely on-point. I'd much rather trust who I'm getting the information and knowledge from now than I would the internet or other sources that may not be as accurate. That's all I gotta say on this subject, so later.

BuddyWh

Agreed... all most of us have to rely on for our information are articles, journals and... yes... the Internet. You obviously have access to a very good source of information... then help us to understand...

Ask your co-workers if the wide range in their oil (like 5w50) is acquired only from the base oils used. Or, what kind of additives (polymers?) are employed, if that is what they use. I think it is fair to say none of us want any information so specific as would divulge a trade secret, so be general as necessary. I doubt we'd understand anything too technical anyway!

Ask them, for long-term drain interval use (like 20k miles), how their oils behave: how seriously are the polymer additives depleted, for instance, how might viscosity ratings be affectied at 15k miles vs. 3k miles, or brand new, for instance. What happens to the polymers? Again, answers in qualititative terms would be adequate, I don't think we need detailed specs (beyond what would be on a spec. sheet.)

Finally: how are their oils different from industry "standards"... again in qualitative terms... different polymer VI extenders? maybe higher quality? maybe none?

Give a little more for us to go on! That's all I'm asking...

The skeptic in me has to observe: I wouldn't bat an eye at using the best super-premium wide-range multi vis synthetic oils and changing at 500 mile intervals if I got the oil... and maybe even the change... for free. Especially for my cherry '65 'Vette with it's classic-V8 loose tolerances (I am taking it at face value when you say mint condition) and a NEED for heavy weight oils!

I really hope we do hear from you again, with a few more details. After all, there can definitely have been changes in oil chemistry that could benefit us all by learning about.

BuddyWh

Jeff92se

iTrader: (82)

Yes, the wide viscosity range problem is much more pronounced in petroleum based oils. Synthetics are a much better in thiw regard also.

IceY2K1

iTrader: (3)

Actually, I was saying that towards the 10W-40 not the 10W-30. Sorry, my writing skills SUCK!

Also, it's not an "old wives' tale", it's TRUE with mineral oils(non-synthetics). Your right though that a 5W-30 is no different than the 10W-30 at operating temperatures with synthetics, but with mineral oils the larger the spread the MORE the oil is thickened with a polymeric plastic which is less effective under high shear conditions such as the BEARINGS and cylinder walls. A 10W-40 is definitely a better choice in HIS case to help TRY and reduce bearing wear.

IceY2K1

iTrader: (3)

Your going to get the SHORT and hopefully sweet version, since I already replied and somehow I/something deleted it. Doooh!

This is true for mineral oils, but NOT necessarily synthetics. At least some weights of Amsoil and I think ALL Redline weights.

Mineral oils start off with say for example a 5W and then add polymeric plastic thickeners to thicken the oil at higher temperatures to end up with a 5W-30. The wider the viscosity range the more thickeners they must add. However, these thickeners are unstable and under high shear conditions such as the bearings and cylinder walls, the 5W-30 is reduced to a 20W(5W-20) or even a 10W(0W-10) and the oil film is not able to provide maximum protection. A 10W-40 requires adding more polymers than a 20W-50 even though they both have a 30 point spread due to the heavier starting base of the 20W-50. So, I assume a 5W-30 would require more polymers then a 10W-30 due to the 25 point spread AND the lighter starting base. Synthetics however have a natural multigrade property(I'm still not exactly clear why, but I'm pretty sure it's chemical bond related), therefore they do not need as much, if any, polymer thickeners/viscosity improvers.


Loser city? Anyways, the difference between a synthetic 5W-30 and 10W-30 during startup is negligible. The Pour Point of AMSOIL differ by ~5F at -70F and the REDLINE by ~4F at -45F. The most important property for cold starts is the borderline pumping temperature, the temperature at which the oil will pump and maintain adequate oil pressure. The AMSOIL is <-40F and the REDLINE is ~-25F for BOTH weights. Synthetics are far superior to mineral oils in cold temps, so a 5W or 10W synthetic is going to provide quicker startups than a mineral oil 5W.


It's a FORD, what more do I need to say? Using a 10W-30/10W-40 synthetic is just an added safety margin incase ambient temps end up 100+F.

BTW, 100F is considered airconditioning here in "loser city". However, back home(which I go regularly) during July, August, and September it regularly breaks 120+F. Let me drive your little Focus around for an hour or two with 5W-20 and I guarantee it's going to be pinging and running hot. Actually, cars ALWAYS ping around here since they downgraded to 91-octane.

AkinAMaXimA

castrol GTX, can't go wrong with that

enicemax

Qualitatively speaking:

-Synthetic base stocks are engineered to contain improved compounds for motor oil use.
-Synthetics withstand the widest range of temperature conditions.
-Synthetics begin to lubricate at lower temps, making cold crank easier.
-Synthetics contain compounds of specific size and shape which reduces volatility burnoff (reaction chemistry).
-Synthetics provide more deposit control.
-Synthetics are "slicker" so they deliver increased lubrication, translating to less wear, cooler engine temp and better performance.

There is no comparison between synthetic and conventional oil, save the fact that they're both engineered to lubricate. There have been several changes in oil chemistry that you're not aware of, which is why conventional motor oil should now be thought of as obsolete. Engines now produce more power and are built to higher tolerances; they operate under high temps and shear conditions. Conventinal oil doesn't provide enough protection in many cases today. And, to answer ur question about long drain intervals, you can go longer on synthetic, although you shouldn't go extended intervals ( i would say no more than 5-7k, even tho i choose to stay on the low end.) because the oil inevitably will get dirty, as will the oil filter. Synthetics are made to protect better, not necessarily to last longer. Obviously the polymers are of much higher (u'r right, u wont understand the additive chemistry, so just take my word for it) quality, and dont break down nearly as readily as in conventional oil, but dirt is dirt, and it can still effect the engine. So, I hope this has shed some light, and I hope everyone realizes that unless your drivin 55, in 70 degree whether, with no body in front of you or behind you, and no passengers in u'r car, you should probably use synthetic to really protect u'r car. Unles its a lease, who gives a crap then. later

Colonel

I do that sometimes and it torques me off. Hit the back button or something and loose everything I wrote! DOH!


I had not read far enough to understand that this was just associated with mineral oil, which after break in period is in NEITHER of my cars or motorcycle.

A buddy of mine here used to live near ya, went to AU, and I pick on him about it all the time. He keeps whining about how he wants to go back. Just a reflex reaction...no harm intended

When you say both weights, you are refering to 5W and 10W right? And you are saying that since the lower range is the same, I get more protection in the upper band due to the 40 vs 30?

It keeps the wife happy and I did not have to drop a bunch of $$$ on the car. She just sees it as point A to point B transporation. Although the FORD engineers need to remove their heads from their posteriors. 3 Coolants lines to the left of the filter, some other kind of hot piece of metal to the right. The only way to INSTALL the damned filters is to jack up the car, feed the filter through the cross memeber and hopefully screw it on correctly! POS!

Currently I have Amsoil 5W-30 in it. When I was under the car looking at the all the heat shielding and pinging (metal contracting as it cools) I really begin to wonder how long the car will really last?

IceY2K1

iTrader: (3)

Yes, 5W-x and 10W-x. With a 10W-30 or 10W-40 you will still have more than enough pumpability during cold starts, but with added protection through a greater temperature range(100+F).

BuddyWh

I'm not trying to compare synthetic to dino oil... it is so stipulated that synthetic is clearly superior (not necessary... but that is clearly off topic.) It is further so stipulated that synthetic is better than dino oil with regard to polymer VI extenders, but still they are used in wide range synthetics. The issue is strictly whether wide range multi-vis is a good idea, even with synthetic oils. I, as an informed consumer, am not comfortable with the idea they are... especially when extending drain intervals.

If I wanted to use synthetic (especially Am$oil), I too would extend drain intervals. I wouldn't want anything in my engine for such a long period with any kind of polymer VI extenders... I'd use only narrow range with no VI extenders (which most any good synthetic is) or straight weight. Unless it's a lease, and as you say, who gives a crap.

Add in that there is no conceivable need to use such a wide-range synthetic simply due to the superior properties of the synthetic.

Sorry, but I need a little more fact and a lot less "trust me... I know better".

Buddywh

IceY2K1

iTrader: (3)

If your interested, appears your quite interested, Im trying to help Bill get a Maxima.org Oil Analysis group project together to test and hopefully PROVE which oil is better. Otherwise, you'll never get a straight answer through all the BS and marketing hype.

Reply and offer to help out:
Organized Maxima.org Oil Analysis Project?(bill99gxe) LONG!

Thanks!

BuddyWh

Thanks for the offer... I would be interested in reading results of your effort... but I don't use synthetic oil and couldn't contribute! As a class I do recognize their superior properties... I just don't see the need to use 'em in non-severe service.

I don't want to re-open the argument, but with all my vehicle I have had very good results on dino oil with frequent changes and rid myself of my cars way before engines are worn, even with high mileage (150k+), because everything else is so worn. I just can't convince myself I could improve on such bottom line performance.

BuddyWh

IceY2K1

iTrader: (3)

I agree with you 100% and I've been telling myself for 12K+ miles that I don't need synthetic as long as I use a quality dino oil and change it EVERY 3K.

Then I discovered some of the advanced protection that synthetics offer that couldn't be matched by a dino even if you change it at 3K, so I had to decide how long I plan on keeping my car. Well I used to think I would get rid of it ASAP, but now with the Fuel Cut TSB performed and the realization that I can live with the crappy paint, I decided to keep it for the long haul since I lost my A$$ on depreciation anyways. Also, I currently have a '93 Sentra w/134K+ miles and I figured I'm probably going to have the Max around as a second vehicle once the Sentra dies or possibly give it to one of my kids, who knows. So, I COULD possibly see 150K+ miles and I don't think the cost is really an issue, since I average far less than 12K miles a year.

We are ALSO interested in dino oil analysis, so if you ever wonder how your dino of choice is holding up or how the internals of your engine(I know your getting rid of it, but it's still facinating to know what's wearing), then feel free to spend/donate a $20 analysis for "The Cause".

Thanks.

iwannabmw

iTrader: (3)

Without dragging myself into this argument any further, I'd like to second the comment that it would be great to have more samples period. It doesn't matter whether the oil is synthetic, coventional or a blend, I think Bill created the spreadsheet to track everything that he could. The more data the better.

IceY2K1

iTrader: (3)

Argument?

BuddyWh

Ya know... I thought the exact same thing with my '92 Integra at ~140k. I just knew I was going for 200k+... the engine and tranny were simply perfect... but then the electrical problems started. Dash lights were intermittent... couldn't get ventilation to change settings... something went with A/C electrical, the comp. clutch was on all the time, even when the engine was off, and ran down battery. It was just too much for a "primary" vehicle... I couldn't rely on it for long trips. Not because of the drivetrain but other things. And I had some other beefs with the car, too.

I have to face it: modern drivetrains, well maintained, will far outlast the rest of the vehicle.

When this 2k1 GXE w/Comf&Conven pkg., 20K, came on a lot last July, at a great deal with new tires, it got me. Someone else ate the depreciation on it and I had been spending close to the payments over the previous 1-1/2 yrs on the Integra in various repairs and "restorations" with only the prospect for more. Why not?

BuddyWh