Does turbo require premium gas?
- Thread starter tubasonic
- Start date
SonicChris
Banned
Generally your bigger companies like Shell, and Exxon use the same amount of detergent in all grades, but when you get into your cheaper brands they tend to do it by grade.
keto06
New member
Really? because Shell advertises their VPower gas as superior (detergent wise) to the other grades. Weird.
SonicChris
Banned
I was going by the "Top Tier" rating. Which most of the major oil companies comply to. I know all Shell gasolines fall under this rating. [EDIT] After doing a little searching, it seems Shell does add more detergent to there "VPower", but from what I can find, no testing out side of Shell shows a benefit to the extra detergent. A couple of the fuel rating sites go as far as to say it's a waste.
all G.M. 2011 cars and trucks that are not diesel eng. take a syntetic blened called dexos. or mobil 1 oil. if not sure check owners manual if not sure check owners manual.GM dexos information center
BrentnKC
New member
From my current experience 87 octane is okay as we are still able to tune significantly more power with 87. I am used to 93 and you may get some benefit especially in hot humid weather for a stock tune but I wanted to share that there is still performance improvement capacity at 87 octane. This being the case, I would say buy 87 unless you are a nut like me and have to have 93.
MGDavis
New member
Shell is a longtime sponsor of Scuderia Ferrari, so of course its recommended. They also mandate the use of their F1 oil sponsor's products in the road cars, iirc.
laborsmith
New member
But is the current nitrogen enhanced Shell gas as good as Shell with Super Platformate?
Laborsmith
Laborsmith
Papasonic
Active member
The dealership here told me to run 87 octane if I want optimum fuel economy... They said the car is set up to run 87 and running the higher octane fuels could wear out internal parts faster. They also told me about the Dexos oil and to trust the oil life reading the computer gives me...
WTF they are idoits. higer octane gas is has less ability to burn (prevents predentonation) not more. I have acuguage and with 87 under heavy acc. the timing advance will be -1 to 0 degrees and with 93 under havy acc the timing advance is around 7-8. so the engine is retarding the timing much less. less retard means less predentonation (which is harmful)
laborsmith
New member
Do we award a gold star for being half right?
Your dealer rep is correct about the oil. Your dealer is so wrong about the octane that I can only say that your dealer is representative of the majority of our Chevy dealers.
In most cases, using octane higher than recommended is a waste of money but in any case it is not harmful to the drivetrain. In the case of a turbocharged Sonic, this is not one of those cases. The ECU is set up to retard timing based on knock, so everytime you fill up your ECU will start as if you used premium, and back off in increments until there is no knock. It is the ECU that allows using premium to be cost effective. And it is this element of the ECU that allows tuners to achieve such impressive gains.
This has been discussed extensively in other threads in this forum, complete with dyno graphs, if you want more assurance.
Laborsmith
Your dealer rep is correct about the oil. Your dealer is so wrong about the octane that I can only say that your dealer is representative of the majority of our Chevy dealers.
In most cases, using octane higher than recommended is a waste of money but in any case it is not harmful to the drivetrain. In the case of a turbocharged Sonic, this is not one of those cases. The ECU is set up to retard timing based on knock, so everytime you fill up your ECU will start as if you used premium, and back off in increments until there is no knock. It is the ECU that allows using premium to be cost effective. And it is this element of the ECU that allows tuners to achieve such impressive gains.
This has been discussed extensively in other threads in this forum, complete with dyno graphs, if you want more assurance.
Laborsmith
RichieRocket
New member
Laborsmith, agree that higher octane will give some level of better mpg, but "is it enough to offset the higher cost" is still an open question. So based on miles per $, mp$ rather than mpg, it may not be better?
For normal commuting, not at high throttle, high load, you are not at the point where knock comes into play, so it may not matter?
Not trying to offend, just asking questions?
Are there dyno plots of stock tune, 87 vs 93 octane back-to-back? I must have missed that, but again, dyno runs are at full throttle.
What we need are Brake Specific Fuel Consumption (BSFC) charts for stock tune with 87 and stock tune with 93. That way we could compare the fuel consumption at part-power....and know for sure!
RichieRocket
New member
gsxr1000, per what laborsmith says, the engine computer backs it off automatically, I'm sure id does it so fast, damage could not occur. But if you never go to full throttle, high load...it may not get close to conditions where knock would occur, so it may not need to retard timing?
How did you see the difference, by monitoring the DIC while driving hwy and cty?
I'm doing the opposite, the last four tankfuls on 87, now switched to 93. On 87 I did 1395 miles on 41.3 gallons = 33.7 mpg It's tough to measure differences for changes like this accurately, but 4 tanks should average out the differences in trips/traffic/conditions .
I doubt you could hear any knock, I would think the control would pull back timing within fractions of a second...
laborsmith
New member
I know there is a lot more info about this on Cruzetalk. I had the dealer fill my tank with 93 and have used it ever since, not so much for improved mileage but because I believe forced induction works better with high octane fuel, so I have nothing to compare as regards mpg.
The ECU works in such a way as you should not hear knock, it should be retarding the timing before you hear it SO if you do hear it get some premium in your tank as quickly as you can. This very topic has been discussed on Camaro5 (I know there is a difference between a Camaro and a Sonic) where some have tried 87 with varying results. It appears sometimes not all 87 fuel is created equal therefore the conclusion over there is if you get some that is less equal than it should be, do your engine a favor by topping off with 93, for medicinal purposes only, I believe.
And I believe Trifecta has posted on their Facebook page relevant info. Per those posting an untuned turbo 1.4 will get better mileage using premium than it will using regular.
But for myself, whether that is true or not, I would only use regular in a forced induction engine if that was only what was available and then top off with premium as soon as I could.
Laborsmith
The ECU works in such a way as you should not hear knock, it should be retarding the timing before you hear it SO if you do hear it get some premium in your tank as quickly as you can. This very topic has been discussed on Camaro5 (I know there is a difference between a Camaro and a Sonic) where some have tried 87 with varying results. It appears sometimes not all 87 fuel is created equal therefore the conclusion over there is if you get some that is less equal than it should be, do your engine a favor by topping off with 93, for medicinal purposes only, I believe.
And I believe Trifecta has posted on their Facebook page relevant info. Per those posting an untuned turbo 1.4 will get better mileage using premium than it will using regular.
But for myself, whether that is true or not, I would only use regular in a forced induction engine if that was only what was available and then top off with premium as soon as I could.
Laborsmith
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BrentnKC
New member
I agree and will run premium as well. But I just put my Sonic on the Dyno with just BP 87 octane with stock tune and then with the Trifecta "octane adjusting tune". The difference is significant in regards of power and especially TQ. The datalog was good as well in regard to knock. The temperature was around 60 degrees.
sipNzipHatchT
New member
i vote yes
ran fine on regular, but noticed the turbo pulling just a little harder on exxon premium.
smoothed the power out just a little
ran fine on regular, but noticed the turbo pulling just a little harder on exxon premium.
smoothed the power out just a little
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gsxr1000, per what laborsmith says, the engine computer backs it off automatically, I'm sure id does it so fast, damage could not occur. But if you never go to full throttle, high load...it may not get close to conditions where knock would occur, so it may not need to retard timing?
How did you see the difference, by monitoring the DIC while driving hwy and cty?
i have a accuguage (i would recommned it esp. for $75.00). i agree if you never go 60% tps then octane is a nul point. but around town not the case for me. i also see about 2psi more on the turbo (10.5 psi to 12.5 psi) at wot.
also surly not much damage occurs when the ecm corrects the timing, 7 degrees is alot of correction and the computer can not adjust it until it happens. so just rather not. also the lack of timming retard and extra boost makes it more fun.opcorn: