mattcgoldstein

I'm in CA and have always run 91. Looking for feedback from anyone running 87 or 89 octane in their stock C6. Any issues or knocking?

Matt

JoesC5

A lot depends on which year/model Corvette you have.

mattcgoldstein

2008 w/ LS3, 1LT, Auto, No Mods.

designerRob

Why???

AJRace

93 is the only thing that hits my tank.....I just don't think to save a couple of bucks it's worth possibly damaging my valvetrain. I've heard lifters rattling after using low octane in other performance cars I've owned. I ran 89 in my old Lincoln LS8 once and thought the valves were coming through the hood until I put a bottle octane boost and some 93 in it. It says premium only for a reason.

Z06LUST

A friend of mine only runs 87...in his C4 Vert (88 or 89), his 04 C5 Coupe and 10 C6 Coupe.
About 100k miles on the C4- no issues, recently broke 50k miles on the C5 and no issues and about 10k on the C6 no issues.

However, he drives in the right lane at or 5mph under the speed limit. Although 61 with 45 yrs of driving experience....he needs driving school but won't go as it will 'stress' the car and maybe break something. Oh, did I mention he is (his term) a Scottish cheap SOB.

So yes for "normal" non-spirited daily driving you can run 87... look in your owner's manual it says so (non Z06). For best performance run 91/93 depending upon where you live (no performance increase with 93 over 91..just some states have 93 instead of 91 and vice versa-car is tuned for 91 so 93 provides NO additional benefit except in the mind of a 16 yr old on Saturday night).

Oh, my 4 Vettes (3 prior and 1 current). Name brand 91...but that is just me.

BSE1956

lh4x4

I have run 87 for years in my LS1,LS2 and LS3 equipped Corvettes. For one reason which is they run well on it. I know how to drive and shift so that the engine is always in a happy zone and not lugging. The valves and engines are in top shape and run as smooth as silk. They are only used for low speed Sunday drives to restaurants and scenic by ways at 5 under the posted speed limit. In this manner they should achieve the 300,000 miles that they were engineered to run.

Chevrolet recommends 91 not requires it. The Government requires that all engines in the US be able to run on 87 octane and the ECM allows for that.

But of course if you modify the motor and go to the strip or track the octane level must match the tune requirements. That is a different story altogether.

I run all my Harley's on 87 also. They too run great.

They also achieve more mpg's. On the trip to Funfest this year the 436 HP LS3 gave 34.5 mpg on 87 octane for the 700 mile round trip. Some of you may remember passing a black coupe on I-57 going 60 mph. The cars are happy and so am I. 40,000 miles on the Vettes and 80,000 miles on the motorcycles.

Why? Oh! $.30/gal. and 10% and up mpg. Seems like a winner to me.

Turbo6TA

Well, even running gas as low as 87 octane won't hurt your engine .. and it won't somehow hurt your valvetrain as one member that posted here thought it might .. there is really no reason to use that low of octane in an engine that has 10.7 compresssion ratio like the LS3.

Praise the good Lord above that the engineers thought to use knock sensors in these engines. With the slightest detection of detonation, the ECU will pull back timing, but when it decreases spark timing, it also results in a decease of available HP.

So, if your happy with reduced performance, be my guest .. run that cheap regular grade pump gas in your new Corvette. Won't hurt a thing, but seems a bit silly to me.

Just my opinion .. do what you feel comfortable with.

george vee

i bought a performance car to perform, 93 does it for me.

BayouCountry

Run the numbers. The higher cost of premium is insignificant in the scheme of things.

FortMorganAl

The car will run on lower octane and, if you drive 10,000 miles a year you might save $50 a year if you bought the same amount of gas. But the car detunes the engine with lower octane and engine efficiency is directly related to mileage. I tested lower octane when I first got mine and the mileage decreased enough to pay for the higher octane. I get about 10% better mileage with 93 octane so if the price of 93 is less than 40 cents more than 87 or 89, I save money by getting the higher octane.

StanNH

I run my Vette with 91 octane, but have tried 89 with no apparent difference. It feels the same, and performs the same. I know the computer will de-tune slightly to compensate for lower octane, but I've never been able to feel the difference in normal driving.

My Audi turbo also requires 91 octane. I've used 89 for the last three years and have seen no difference in performance or gas mileage either.

There is a difference because we all know the car de-tunes slightly, but it really is not a huge difference.

Having said that, I'll continue to run premium in my Vette just because it's a Vette.

mcandrew67

Geeez, I hope I never come up behind you
If I were a cop this is what I would do to you lmao

Eppieguy

My father has a 05 tuned w/ intake, headers and Corsa's and runs 87 with no issues to date. He's not out tracking the car but does enjoy getting on it from time to time. Me, 91 all the time in my 09.

JUIC3D

Any money saved on the cheaper price of gas (87 octane) is lost when you get lower MPG because the motor is not as efficient.

topper7788

It will run fine on 87.... If your tracking the car or always running it very hard than upping the octane is not a bad thing but for 99% of us it's really fine...

topper7788

I have never noticed any MPG difference by using lower or higher octane fuel... A did a test with my previous corvette which was normally run on regular and did 3 tank fulls with 93 Octane and got ZERO difference in MPG... I'm currently doing the same with my new 2011 to see if there is any difference on this car... But I'm only on my 2nd tank of premium .. So I can't speak for results..

j_digi454

I can't believe anyone would by a "performance" car and then reduce it's performance to save what? A few pennies?

Just my opinion.

dvilin