A thread about gas
02-26-2013, 10:59 AM
#41
I would just "be a thoughtful husband" and fill the up the tank for her any time it is getting low 
I doubt "switching back and forth" would really cause a problem, as the engine with reduce the timing when it senses knock. Apropos knock: make sure your knock sensor is in working order.
Or, the best solution imo would be doing the calculation of the cost of running low and high octane fuel and then showing her the math. It doesn't cost that much more. Tell her: "It's science!"
http://www.youtube.com/watch?v=56pVgyX3iqg
I doubt "switching back and forth" would really cause a problem, as the engine with reduce the timing when it senses knock. Apropos knock: make sure your knock sensor is in working order.Or, the best solution imo would be doing the calculation of the cost of running low and high octane fuel and then showing her the math. It doesn't cost that much more. Tell her: "It's science!"
http://www.youtube.com/watch?v=56pVgyX3iqg
02-27-2013, 07:27 AM
#42
Member
Join Date: Aug 2011
Location: Levittown, NY
Posts: 107
I just sold my girl on a cost-benefit in $ savings vs the increased mpg, 93 still makes the car run better, plus with the increased mpg you're not really spending anything extra. Maybe a dollar per tank. Worked so well she started using 93 in her sentra. I told her that car def didn't need it lol but she even says it runs better with it.
Considering our cars run like **** on 87 anyway... I don't care what u say about the ecu and all the bs, when I FEEL my car run like garbage with 87 as opposed to 93, that tells me to run 93. I'm not gonna pinch pennies about it. I'm also gonna use castrol gtx high mileage oil because I like taking care of my car...
Considering our cars run like **** on 87 anyway... I don't care what u say about the ecu and all the bs, when I FEEL my car run like garbage with 87 as opposed to 93, that tells me to run 93. I'm not gonna pinch pennies about it. I'm also gonna use castrol gtx high mileage oil because I like taking care of my car...
02-27-2013, 11:35 AM
#44
I just sold my girl on a cost-benefit in $ savings vs the increased mpg, 93 still makes the car run better, plus with the increased mpg you're not really spending anything extra. Maybe a dollar per tank. Worked so well she started using 93 in her sentra. I told her that car def didn't need it lol but she even says it runs better with it.
Considering our cars run like **** on 87 anyway... I don't care what u say about the ecu and all the bs, when I FEEL my car run like garbage with 87 as opposed to 93, that tells me to run 93. I'm not gonna pinch pennies about it. I'm also gonna use castrol gtx high mileage oil because I like taking care of my car...
Considering our cars run like **** on 87 anyway... I don't care what u say about the ecu and all the bs, when I FEEL my car run like garbage with 87 as opposed to 93, that tells me to run 93. I'm not gonna pinch pennies about it. I'm also gonna use castrol gtx high mileage oil because I like taking care of my car...
That, or you are experiencing a well known placebo effect.
Even when I put 87 in my 2001, which specifies no lower than 89, it runs perfectly fine. All 3 maxima's I've owned have been this way. The 97 got slightly worse mileage on 87, but that was it.
02-27-2013, 10:23 PM
#45
Member
Join Date: Feb 2012
Location: Murfreesboro TN
Posts: 261
If your car runs bad on 87, there is something wrong with your car. Not all maximas, just yours.
That, or you are experiencing a well known placebo effect.
Even when I put 87 in my 2001, which specifies no lower than 89, it runs perfectly fine. All 3 maxima's I've owned have been this way. The 97 got slightly worse mileage on 87, but that was it.
That, or you are experiencing a well known placebo effect.
Even when I put 87 in my 2001, which specifies no lower than 89, it runs perfectly fine. All 3 maxima's I've owned have been this way. The 97 got slightly worse mileage on 87, but that was it.
I ask because I've seen some articles that show ethanol resists knock better than gasoline, there-by raising the point that knock would occur.
You can't rely on that for MPG...you have to do it by tank at each fill up. Of course, if you are thinking about MPG you are automatically changing your driving habits subconsciously to improve your MPG.
The only real test is to do it tank by tank over a long-term such as a month, or better yet, a few months.
The only real test is to do it tank by tank over a long-term such as a month, or better yet, a few months.
Can't wait to get a new reading after the next tank!
02-28-2013, 01:09 AM
#46
Member
Join Date: Aug 2011
Location: Levittown, NY
Posts: 107
I'm not the only one that had experienced engine knocking with lower octane fuels, I don't know about you but I consider that "running like ****", knocking is definitely bad for your car and I definitely can feel a difference in power between 87 and 93. I don't know about your car but we have 2 different engines.
The Maxima's ignition timing is tuned for 91+ octane fuel, and the compression ratio (10.0:1) is high enough that higher octane fuel is required to prevent knocking. If you use lower octane fuel, the engine will start knocking, the knock sensor will detect that, and then send codes back to the ECU telling it to retard the timing to prevent the knocking. The the timing will be off and you'll lose power, but at least then the engine won't be knocking.
The octane requirements of an engine are most directly related to the COMPRESSION RATIO of the engine. The rule of thumb is that if you have a 9.xx:1 CR or lower engine, you can usually get by with 87. If you have an engine with a 10.0:1 CR or higher, you'll most likely need 91 for best performance.
The Maxima's ignition timing is tuned for 91+ octane fuel, and the compression ratio (10.0:1) is high enough that higher octane fuel is required to prevent knocking. If you use lower octane fuel, the engine will start knocking, the knock sensor will detect that, and then send codes back to the ECU telling it to retard the timing to prevent the knocking. The the timing will be off and you'll lose power, but at least then the engine won't be knocking.
The octane requirements of an engine are most directly related to the COMPRESSION RATIO of the engine. The rule of thumb is that if you have a 9.xx:1 CR or lower engine, you can usually get by with 87. If you have an engine with a 10.0:1 CR or higher, you'll most likely need 91 for best performance.
02-28-2013, 02:28 AM
#47
Read a quick wiki here.
The Maxima's ignition timing is tuned for 91+ octane fuel, and the compression ratio (10.0:1) is high enough that higher octane fuel is required to prevent knocking. If you use lower octane fuel, the engine will start knocking, the knock sensor will detect that, and then send codes back to the ECU telling it to retard the timing to prevent the knocking. The the timing will be off and you'll lose power, but at least then the engine won't be knocking.
The octane requirements of an engine are most directly related to the COMPRESSION RATIO of the engine. The rule of thumb is that if you have a 9.xx:1 CR or lower engine, you can usually get by with 87. If you have an engine with a 10.0:1 CR or higher, you'll most likely need 91 for best performance.
The octane requirements of an engine are most directly related to the COMPRESSION RATIO of the engine. The rule of thumb is that if you have a 9.xx:1 CR or lower engine, you can usually get by with 87. If you have an engine with a 10.0:1 CR or higher, you'll most likely need 91 for best performance.
The VQ35DE compression ratio is 10.3:1.
While it is true that CR largely dictates minimum fuel octane levels, it has become much less so in recent years. Specifically, with the adoption of continuously variable valve timing and lift, knock sensors, direct injection (DI) -- which effectively means that only air is being compressed for the majority of the compression stroke and the charge is cooled as the fuel is injected --, and alternative cycles (e.g. Atkinson, late intake-valve closing), there has been a general increase in CR without always necessitating a need for higher-octane fuels. True, if the engine is performance-oriented, it will make more power and use less fuel on 91+ AKI vs. 87 AKI, but the take-home message is that it is no longer required (read: almost all modern engines can "get by" on lower-octane fuels). Two examples below:
New Corvette LT1
"The new small block also benefits from the latest advanced engine tech like direct injection, continuously variable valve technology and a relatively high 11.5:1 compression ratio... Chevy also notes that while premium fuel is recommended, it is not required with the LT1."
Mazda SKYACTIV-G (CR of 14.0:1 outside the US)
"The new engine only runs on the Atkinson cycle at light load, thanks to a camshaft adjuster that can rotate the intake cam up to 70 degrees, much further than anything else on the market. When full power is requested—the U.S. engine will have a 13:1 compression ratio to deal with our 87 octane fuel—the computer switches the intake timing to more closely resemble the Otto cycle. The result is 158 horsepower and 151 lb-feet of torque."
Last edited by tcb_02_max; 02-28-2013 at 09:29 AM.
02-28-2013, 07:06 AM
#48
I'm not the only one that had experienced engine knocking with lower octane fuels, I don't know about you but I consider that "running like ****", knocking is definitely bad for your car and I definitely can feel a difference in power between 87 and 93. I don't know about your car but we have 2 different engines.
I'm telling you, there is something wrong with your car if you consistently have knocking/pinging with 87 Octane.
And I have had a 97, 01, 03, and an 03 G35 with the same engine as the maxima pretty much, spec'd the same as it is for fuel and CR. I've run the Nissan engines that call for 89, and the ones that call for 87.
All engines run great on what they're spec'd for. And the 97 and 01 both ran perfectly fine on 87 also, despite being spec'd for 89 or higher.
Again, I know saying this sounds insulting, but if your car is knocking with 87, THERE IS SOMETHING WRONG WITH IT. No biggie, just accept that.
If running 89+ solves the problem, give 'er, I would, but that doesn't condemn all properly functioning VQ35DE's to 'have to run' 89+ just because you do, that's all I'm saying dude.
The Maxima's ignition timing is tuned for 91+ octane fuel, and the compression ratio (10.0:1) is high enough that higher octane fuel is required to prevent knocking. If you use lower octane fuel, the engine will start knocking, the knock sensor will detect that, and then send codes back to the ECU telling it to retard the timing to prevent the knocking. The the timing will be off and you'll lose power, but at least then the engine won't be knocking.
The octane requirements of an engine are most directly related to the COMPRESSION RATIO of the engine. The rule of thumb is that if you have a 9.xx:1 CR or lower engine, you can usually get by with 87. If you have an engine with a 10.0:1 CR or higher, you'll most likely need 91 for best performance.
The octane requirements of an engine are most directly related to the COMPRESSION RATIO of the engine. The rule of thumb is that if you have a 9.xx:1 CR or lower engine, you can usually get by with 87. If you have an engine with a 10.0:1 CR or higher, you'll most likely need 91 for best performance.
Only the 95-01 were spec'd for 89+
2. Compression ratio is one of the bigger variables in what octane is needed, sure, but it's not the be-all end-all reason. You cannot make a statement like 9.0:1 = 87 AKI and 10.0:1 = 89 AKI and so on, that is just ignorant, and wholly incorrect.
Your understanding of how this all works is wrong, that's all.
02-28-2013, 02:51 PM
#49
I tend to agree that the knocking or power loss you experience when using 87 octane is symptomatic to other issues your Maxima is experiencing.
It may be good to run more 87 and start diagnosing those symptoms to see what problems you are having. Running the higher octane can be a band aid fix covering up the issue until it becomes progressively worse.
FWIW...I have a 2k and ran 91 octane for about 2 years after I bought it new. Since that time I have run 87 octane with no issues or difference in performance. Pretty much all gas I've used has the 10% ethanol since I'm in California.
It may be good to run more 87 and start diagnosing those symptoms to see what problems you are having. Running the higher octane can be a band aid fix covering up the issue until it becomes progressively worse.
FWIW...I have a 2k and ran 91 octane for about 2 years after I bought it new. Since that time I have run 87 octane with no issues or difference in performance. Pretty much all gas I've used has the 10% ethanol since I'm in California.
02-28-2013, 03:56 PM
#50
Junior Member
Join Date: Sep 2011
Location: Atlanta, GA
Posts: 49
In my 03, I started having what I thought was valve rattle at around 175K miles. When I bought the car in 04, I used 93 octane exclusively for the first 4 years or so before reluctantly switching to 87. When the "rattle" started last year (primarily at low rpms uphill), I decided to try 93 again. The rattle that lasted a year was literally gone with one tank of premium fuel. Never noticed any power loss or other negative consequences while running 87 until the "rattle" after 4 years of regular. Not adding an opinion in either direction here, just sharing my experience. Would issues related to spark knock sound like what I described, or is that another issue altogether?
02-28-2013, 07:36 PM
#52
I don't understand the point gas wars. Usually the bigger the engine is, the better its at coping with lower octane fuel. Besides, nearly all consumer cars are tuned from the factory to run on 87 just fine, there is a reason why we have knock sensors. Unless your car is custom tuned for a specific fuel octane or can take advantage of it, there is no need to put anything more than 87.
I use 93 because i get better fuel economy, and when i did the math back on my 04 maxima id spend the same when compared to 87 vs 93, but id simply get more mpgs with 93, so i just went with 93 for more range.
I use 93 because i get better fuel economy, and when i did the math back on my 04 maxima id spend the same when compared to 87 vs 93, but id simply get more mpgs with 93, so i just went with 93 for more range.
03-07-2013, 08:10 PM
#55
With gas prices the way they are, I've just decided that I'm going to run my vehicles on farts. Seems to be the only gas I can afford these days. I can deal with a $65 fill up with premium on the Maxima. But the $150 fill up with 87 on the monster V10 Excursion is killing me. How about we all stop bickering about which gas to use and start figuring out a way to run our cars on the gas God gave us! I'll donate some funds via PayPal to whomever engineers that!
03-07-2013, 08:15 PM
#56
^
Using 87 full tank. I am averaging 350-370 KM right now (with tiny tiny half bar left over) in "winter" Canada.
The car is a fairly stock 02 Maxima..
Using 87 full tank. I am averaging 350-370 KM right now (with tiny tiny half bar left over) in "winter" Canada.
The car is a fairly stock 02 Maxima..
Last edited by george__; 03-07-2013 at 08:18 PM.
03-07-2013, 09:41 PM
#57
Member
Join Date: Mar 2012
Posts: 142
went to the pump recently..saw the last guys total was $135 for 34 gallons..what the F*CK? first off wth has a 34 gallon tank that isnt a rig (rigs cant use the pump im talking about, no clearance)? and second why would someone do that to themself..
03-07-2013, 09:59 PM
#58
My old '90 F150 had two gas tanks/iirc around 30 gallons+ for both of those.
03-08-2013, 12:37 AM
#59
With gas prices the way they are, I've just decided that I'm going to run my vehicles on farts. Seems to be the only gas I can afford these days. I can deal with a $65 fill up with premium on the Maxima. But the $150 fill up with 87 on the monster V10 Excursion is killing me. How about we all stop bickering about which gas to use and start figuring out a way to run our cars on the gas God gave us! I'll donate some funds via PayPal to whomever engineers that!
03-08-2013, 06:32 AM
#61
Member
Join Date: Aug 2011
Location: Levittown, NY
Posts: 107
Its the original owners manual from my 02. Still had it when I bought the car lol go figure, along with all the original receipts, speaking of which im gonna have to do a timing belt soon >_< but thats another search.. it's on page 9-2
03-08-2013, 06:37 AM
#62
Junior Member
Join Date: Sep 2011
Location: Atlanta, GA
Posts: 49
And boats! While it's certainly better to use the non-ethanol marine gas, there has been the occasional fill up at the regular gas station. And seeing as the boat has a 100 gallon tank 
, it would usually require multiple transactions since most of the credit card pre-authorizations only grant you $75 to $100 at a time .
, it would usually require multiple transactions since most of the credit card pre-authorizations only grant you $75 to $100 at a time .
03-08-2013, 06:44 AM
#63
Junior Member
Join Date: Feb 2013
Location: Austin, TX
Posts: 22
higher octane gas can only burn "better" if the vehicle can sense octane (or knock) and adjust the timing to take advantage of the fact.
03-08-2013, 08:32 AM
#64
What car is that manual for lol
03-08-2013, 08:57 AM
#65
That's same exact statement from my 98 I30 manual, and therefore all 95-99 Maximas.
What is always always always missing from these gas discussions is environment, or location. A maxima in the mile high city of denver colorado is less likely to need premium than that very same maxima when its in LA or NY, at sea level. That Maxima, when its in Denver probably wont ping at all using 87 octane, but ping like crazy when it gets to NY using 87 octane.
If you read further along in the manual, it states that in high altutude areas (over 4000 ft) like Colorado, Montana, new mexico, Wyoming etc, you can use octane as low as 85
What is always always always missing from these gas discussions is environment, or location. A maxima in the mile high city of denver colorado is less likely to need premium than that very same maxima when its in LA or NY, at sea level. That Maxima, when its in Denver probably wont ping at all using 87 octane, but ping like crazy when it gets to NY using 87 octane.
If you read further along in the manual, it states that in high altutude areas (over 4000 ft) like Colorado, Montana, new mexico, Wyoming etc, you can use octane as low as 85
03-08-2013, 10:19 AM
#67
Overall, its a mediocre gain. When i had my old 02 mazda 626, couple of times i used 93 in it and got extra 30 miles out of the tank, take it with a grain of salt as i don't remember exact figures. It had a 2L 4 cylinder engine with 4 speed auto.
It all depends on the engine and its tune.
03-08-2013, 10:53 AM
#69
Senior Member
Join Date: Feb 2012
Location: Rollinsford NH
Posts: 413
I have the 3.0 engine, and I used to get 400 miles to a full tank of premium fuel, now i'm getting around 300ish, same fuel same driving habits, I think they put something in the gas around the winter time.
03-08-2013, 12:01 PM
#70
In my G35, i get about 250 miles on 15.1 gallons. Today after 2 tanks of 93, i got 250 miles and 13.8 gallons in. My driving habits haven't changed.
Overall, its a mediocre gain. When i had my old 02 mazda 626, couple of times i used 93 in it and got extra 30 miles out of the tank, take it with a grain of salt as i don't remember exact figures. It had a 2L 4 cylinder engine with 4 speed auto.
It all depends on the engine and its tune.
Overall, its a mediocre gain. When i had my old 02 mazda 626, couple of times i used 93 in it and got extra 30 miles out of the tank, take it with a grain of salt as i don't remember exact figures. It had a 2L 4 cylinder engine with 4 speed auto.
It all depends on the engine and its tune.
03-08-2013, 12:35 PM
#71
Member who somehow became The President of The SE-L Club
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Posts: 16,033
My partner works for BASF - The Chemical Company.
They supply the Big 3 with the additives for the gas.
All 3 company's buy the same products.
None of the products are called "Techron" or "Invigorate".
It's called Marketing.
You should use the correct octane rating for your vehicle. But it wont die if you don't.
Other then that, it's nothing but Marketing.
They supply the Big 3 with the additives for the gas.
All 3 company's buy the same products.
None of the products are called "Techron" or "Invigorate".
It's called Marketing.
You should use the correct octane rating for your vehicle. But it wont die if you don't.
Other then that, it's nothing but Marketing.
Last edited by njmaxseltd; 03-08-2013 at 12:42 PM.
03-08-2013, 12:36 PM
#72
Not sure, all i know i gained MPGs by just putting in higher octane gas.
03-08-2013, 01:33 PM
#73
Here. It's actually in the how to stickies, if you want to check later and can't remember how.
I posted this in another fuel thread a long time ago.
The PROPER way to calculate MPG is:
1. Fill tank completely
2. Reset speedo
3. Drive as far as you feel like, doesn't matter much
4. Re-fill your tank completely
5. Record miles driven between #2 and #4
6. Record Gallons you put in tank at #4
7. Divide Mile reading you got at #5 by Gallon reading you got at #6
EXAMPLE:
1. Fill tank completely done
2. Reset speedo 0 miles
3. Drive as far as you feel like, doesn't matter much 200 miles
4. Re-fill your tank completely done
5. Record miles driven between #2 and #4 200 miles
6. Record Gallons you put in tank at #4 8 Gallons
7. Divide Mile reading you got at #5 by Gallon reading you got at #6 200 Miles / 8 Gallons = 25 MPG
This is why these threads fail, no one has a bloody clue how to calculate their mileage, and everyone throws out numbers.
03-08-2013, 02:28 PM
#75
Senior Member
Join Date: Feb 2012
Location: Rollinsford NH
Posts: 413
It means, I filled my tank completely right when the gas light came on, reset my mileage to zero, drove the car until the gas light came back on again, and saw what the number was at. How does that not make sense?
And I don't care if it's not the proper way to calculate mpg, it's just how I calculate it.
Bucko
And I don't care if it's not the proper way to calculate mpg, it's just how I calculate it.
Bucko
03-08-2013, 02:33 PM
#76
It means, I filled my tank completely right when the gas light came on, reset my mileage to zero, drove the car until the gas light came back on again, and saw what the number was at. How does that not make sense?
And I don't care if it's not the proper way to calculate mpg, it's just how I calculate it.
Bucko
And I don't care if it's not the proper way to calculate mpg, it's just how I calculate it.
Bucko
03-08-2013, 02:51 PM
#77
Senior Member
Join Date: Feb 2012
Location: Rollinsford NH
Posts: 413
I just now filled up with 93 octane, because my gas light came on. It cost me $61 exactly, and I got 15.726 gallons, and I reset my mileage. Now I'll watch it, and when the light comes on again, I'll report back what number its on.
I'll divide whatever number the mileage on the dash is showing by the number of gallons I just put in my car. Then, I'll have my MPG.
I'll divide whatever number the mileage on the dash is showing by the number of gallons I just put in my car. Then, I'll have my MPG.
Last edited by 5aprilc; 03-08-2013 at 03:13 PM.
03-08-2013, 02:51 PM
#78
If your car runs bad on 87, there is something wrong with your car. Not all maximas, just yours.
That, or you are experiencing a well known placebo effect.
Even when I put 87 in my 2001, which specifies no lower than 89, it runs perfectly fine. All 3 maxima's I've owned have been this way. The 97 got slightly worse mileage on 87, but that was it.
That, or you are experiencing a well known placebo effect.
Even when I put 87 in my 2001, which specifies no lower than 89, it runs perfectly fine. All 3 maxima's I've owned have been this way. The 97 got slightly worse mileage on 87, but that was it.
I think the bottom line is that if your car doesn't run the same on 87 as 91/93, then you're actually not saving money b/c efficiency is lost.
I've never ran less than 91 (99% 93) in mine, but my cheapskate *** friend had been using 87 for a long time and wondered why he heard tons of pinging when accelerating
I told him to fill it up with 93 and I got a call that the pinging was gone and he had major power gains.I told him "no ****."
Last edited by Child_uv_KoRn; 03-08-2013 at 02:57 PM.
03-08-2013, 03:20 PM
#80
I just now filled up with 93 octane, because my gas light came on. It cost me $61 exactly, and I got 15.726 gallons, and I reset my mileage. Now I'll watch it, and when the light comes on again, I'll report back what number its on.
I'll divide whatever number the mileage on the dash is showing by the number of gallons I just put in my car. Then, I'll have my MPG.
I'll divide whatever number the mileage on the dash is showing by the number of gallons I just put in my car. Then, I'll have my MPG.