Regular Or Premium??

[Donne Trav]

I just "Googled" — "best rated gas for Corvettes" — and saw a lot of info
saying there's not much difference in REGULAR and PREMIUM gasoline.
Is this a fact? Wouldn't the higher OCTANE in the PREMIUM be better
for these "muscle" cars? WHAT DO YOU USE?

 

[minifridge1138]

You've picked a topic that is going to cause a lot debate.
There are already several threads about this.

Personally, my car runs just fine on 87 octane. Of course the L83 is not the highest performance Corvette ever made. With a compression ratio of 9:1 (at best) i don't need higher octane.

The computers in newer cars will adjust the spark timing and fuel curve to run on whatever octane you use (as long as it is at least 87). Lower octane may cause the computer to run less advance to avoid pre-detonation and that will have an impact on torque and horsepower. But the impact will be so small that you will never notice without a dynometer and a computer.

I know a guy with a C5 Z06 that get 30+ mpg with 87 octane and has no problem hauling @$$.

Other people will insult you for using anything less than 93 octane.

Good luck and watch the comments fly!

Oh, and Corvettes are Sports Cars not muscle cars.

 

[gmjunkie]

I know a guy with a C5 Z06 that get 30+ mpg with 87 octane and has no problem hauling @$$.

Other people will insult you for using anything less than 93 octane.

Good luck and watch the comments fly!

You got that right!!!

I too personally Know a guy that has a Z06 that does just fine on 87 octane,But unfortunately he can't do any better than about 28-28.5 MPG!!I think it has more to do with his Lead Foot!!
But his 03 Z-51 6sp does well above 30 and 94 LT1 6sp about 30 +/- on the open road!!

 

[formul8]

The car will run ok on 87.

The car will run better on 89.

The car will run best on 91 or higher.

End of debate.

 

[air1jpg]

You got that right!!!

I too personally Know a guy that has a Z06 that does just fine on 87 octane,But unfortunately he can't do any better than about 28-28.5 MPG!!I think it has more to do with his Lead Foot!!
But his 03 Z-51 6sp does well above 30 and 94 LT1 6sp about 30 +/- on the open road!!

Hey Junk!
What gas mileage do you think a 96 LT1 w/an auto should get? I get an average of 19.6 miles per gallon.

 

[gmjunkie]

Hey Junk!
What gas mileage do you think a 96 LT1 w/an auto should get? I get an average of 19.6 miles per gallon.

I've had 3-4 of them that would get 26-27 on a trip!!

 

[G Winter]

I have done a comparison on my 90 6 sp. I do get a little better mileage with the higher octane. As much as 2 mpg.
I wouldn't say that it would hold true in all corvettes.

Glenn

 

[air1jpg]

I've had 3-4 of them that would get 26-27 on a trip!!

Then I guess getting an average of 19.6 with a 70/30 city/hwy mixed isn't too far off in line with 26-27 on a mostly hwy trip.

 

[CorvetteArchives]

It will run PERFECT...cant get better on 90 octane. Alternate between 91 and 89 at exactly half a tank.
But dont you DARE use an octane booster or Hib might come to your house and beat you senseless

 

[SkyKing]

I've done a lot of testing of 93 vs. 89 or 87.
My C6 Automatic ran 2 tenths and 2 mph faster in the 1/4 with 89 octane. I plan to run it again with 87. It doesn't ping and it feels more powerful with the 87.
To test it, I first ran with about 2 gals of 93. I made two runs. Then I put in 3 gals of 87, to get about 89 octane and made two more runs. It didn't surprise me that it was faster on 89. It felt much more responsive.
Re: gas mileage
I drove to Florida on I-95 from SC. After fill-up with 89 octane, I went 65 and 70 mph on cruise control (2 short stops) for the last 200 miles. This 400hp vette averaged 35.2 mpg and verified at fill-up at the end. Amazing car!
My wife's 07 Acura manual says premium is recommended. It gets 3 to 5 mpg better on 87 octane and runs great. Didn't test at track, but the mpg test was over 2000 miles. 1000 on 93 and 1000 on 87 on the return. We got 35mpg on 87. Same as the vette and the Acura is a 4 cyl.!!!
You should use higher octane fuel, if your engine pings. Light pinging is ok, but heavier pinging can do severe internal damage (rings, gaskets, pistons, etc.).
High octane fuel contains slightly LESS energy than lower octane. The additives used to raise octane do not increase energy. They lower it. It is like adding water to the gas. As a matter of fact, we used to spray water into old aircraft engines to raise the octane level. It is necessary on some high compession engines, but these vettes with variable valve timing seem to be much more flexable.

 

[tonylong]

My 89 (L-98) only likes premium. It runs rough and stumbles on anything else. I recently switched from Exxon/Shell to Hess because Hess uses Domestic crude. It never liked Hess, and after just filling up it's now really rough and surges when stopped with brake on.
I get 15 in traffic, 22 is the best I've made on the Interstate when cruising in the 80's and up, typical mix is 17.5.
No codes being thrown, and just replaced plugs and wires in May. I'll switch to NON-ethanol premium if I can find any.