I heard that you can use regular gas in a vette with no problems or harm for the engine. Just wondering if anyone is doing it and if it is bad for your car. Not that I am going to do it, just heard about it. Gas prices suck. 3.55 for premium

 

I use regular in mine, no problem. A little knocking under hard acceleration on occasion, and not as much power, but I don't believe it harms anything.

s'noJob

 

The spark advance in the motor is setup for premium. The PCM will detect knock and pull timing if you run regular. The timing pull will hurt your gas milage...most likely enough to offset the price difference in the gasoline and cost you more $$$. Not to mention that if the PCM doesnt catch the knock that you might hurt your motor. So to sum it all up...its a bad idea.

 

 

This subject always generates a lot of debate and is posted almost weekly.

The owners Manual actually says:

“Fuel - Gasoline Octane

Use premium unleaded gasoline with a posted octane of 91 or higher for best performance. You may also use middle grade or regular unleaded gasoline rated at 87 octane or higher, but your vehicle’s acceleration may be slightly reduced. If the octane is less than 87, you may get a heavy knocking noise when you drive. If it is bad enough, it can damage your engine.”

E-T, who was involved in the design of the C5, will post an explanation of why the high compression of the LS1 needs good gas (he said 91 minimum and 93 if you could get it). It has a knock sensor which automatically retards the ignition if it senses knock. If its doing that, by definition you have less power and lower fuel efficiency.

In my book, although it may protect the engine to a certain degree, it’s still a compensatory adjustment. In other words it’s solving the problem after the event so some damage could occur however slight.

For a couple of cents a gallon, I won't take the chance. JMHO

In UK Regular gas is 95 octane (RON) which equates to 91 octane in the US. The Super Unleaded is 98 octane which is about 93/94. I use the Super when I can get it but not all gas stations sell it here. And BTW, I pay nearly $9.00 a gallon for my gas. Even at that price I'll pay the extra for decent octane

 

X2.

 

You will lose both gas mileage and power by running regular and you will hear knock on hard acceleration...
It is not worth the difference in price in my opinion to run regular..

 

At the Mid America Vette Fest in Effingham in 07. A retired GM engineer who spent his career in the Corvette division said at a seminar that it was okay to use 87 octane. In fact he said it was a waste of money to use 91 or more unless you were racing.

I have always used 87 octane and have never had any detonation. I got 32 mpg with my 02 vette on the way to Effingham from the Quad cities. I must disclose that all the other vettes were passing me because I drive five under the limit on the interstate.

 

I made the mistake of putting 89 octane in, BLAH! no performance Back to 92-93 octane for me

 

I ran premium the first few years in my 01 and then went to regular and I cant tell a diffence but when my son took the car to iowa he deff got better fuel economy coming back with premium in it.

It does kill power a bit the funny part is the only reason I noticed it is with premium my automatic bone stock chirps the tires into 2nd gear with regular it doesnt haha

 

I need to read more of these octane threads. I'm still pretty new here, and just today put down a deposit on my C5 Z06!

I'm curious about this mainly because I live in Alaska, and for some reason the highest octane we can buy is 90. Manual recommends 91. I've always wondered if this would pose a problem... I'm thinking ONE octane point won't make too much difference. Especially if some of you are running 87/89. However... mine being a Z06, would probably be pickier would it not? If the 90 octane gives me trouble, would an octane booster be acceptable? i guess I don't really have another option at this point but wait and see. I won't ship the car to Alaska until April when winter passes so I have a few months.

 

i accidentally put 87 in my 03 and it ran like crap
until i got to a parts store and boght octane booster i dont care what people think anything less than 91 is a no no

 

No C5 engineer would ever say that using 87 octane is OK and that using premium is a waste of money, I would venture to say that you were spoofed by a wanna Be....

Here is proof... if it was OK to run regular in a Corvette, there would be millions spent on advertising that very thing... and in the owners manual it specifically says 91 or higher..Not only that but the free press we would get for developing a car that has 350 hp and runs on regular gas.

Here is the problem... you can run 87 octane in the car... but only if nothing else is available.. the car will run.. but not the way it was designed.( this 87 octane OK is only in an emergency situation. engine knock is a very bad thing causing all kinds of problems from cracked wrist pins, to actually burning a whole through the piston.. to crank bearing failure.. of course this all occurs over time.. the difference in cost between 87 and 91 is usually ten cents a gallon, and on a fill-up , it equates to 2 dollars..
Depending on how much carbon build up you have 91 octane may not be enough. If the knock sensors detect this they will retard the spark, reducing power and fuel economy. Anyone who claims that a little knock
wont hurt needs to rethink their automotive skills. if that were the case we would not have designed the knock sensor algorithms.. and if you think that by having them you can push the car to knock because you are protected, you are sadly mistaken..

 

Using premium is a waste of money. I have used regular in my vette for 4 years with no problems. Its all the same anyway. All you are doing
by buying premium is making the oil companies richer.
I even asked Corvette expert Gordon Killebrew he said regular was
perfectly fine. Nuff said.

 

If you are going to drive a car like a Vette why not put the best into the motor? I wouldn't use anything but premium! What does the cost difference come out to be for a better gasoline?

 

 

not a good idea.

 

If saving a few cents a gallon is an issue, sorry to say……you bought the wrong car…..get yourself a Ford Pinto.

 

 

First of all Gordon is not an engineer , he is an assembly line mechanic, and is very knowledgeable with the C4 platform...
with the L98 engine and the LT1 both completely different animals.. BTW Gordon's specially was trouble shooting wiring problems at the end of the assembly line... Asking him about using regular in an LS1/6 would be like Lucy Hood if it was OK to use regular, I dont think even Lucy would say it was OK and she is the C5 Senior Project engineer for interior design. Now if you asked someone with some credibility with the C5 like Now if you asked John Juriga or ED Koener, small block production chief C5 engineer they would tell you differently..
Take it from someone who know the C5 platform.. do Not use 87 octane in your LS1/6.

Now that is Enough said.