Just wondering If any one uses 87 octane fuel in your stock C5?? there is a guy at work that Kind of shuffels back and forth from 87 to 91 witch would give him closer to mid grade, but if a person runs in to a time you need fuel and no 91 is around how bad of an idea is this??>>>>>>>>>>>thanks Greg

 

I'm sure it wouldn't kill you in a pinch, but I certainly wouldn't make a habit of it......

 

I would not make it a habit using low octane .With the milage these things get why would you care .Use the factory recommened fuel it is a vette .

 

I'm sure I will get some arguements/flames on this one. You CAN run 87 octane in your STOCK Vette if you want. I've done it a couple times just to test, because I was curious. I did notice a loss in power. It will not hurt your stock engine, because the computer will adjust for the lower octane fuel. Now if you have lots of mods on you engine, this may not be true. I just have a cold air intake, and a hurst shifter. Also the owners manual says "Premium Fuel Recommended", it doesn't say required. Actually I looked it up, here is what it says.

"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 or higher, but your vehicles acceleration will be slightly reduced. If the octane is less than 87 you may hear a heavy knocking noise when you drive. If it is bad enough you can damage your engine."

 

The Corvette manual says it's okay....the computer recognizes the lower octane fuel but performance is diminished. However, since it not recommended and just my 2 cents, I didn't spend good money for diminished results. That's just not right.

 

 

My baby gets nothing but the best.

 

When I have accidentally put 87 in it pings!

 

I'll stick with 93 octane for my car. I would hate to hear it sounding like it's rumming on marbles.

 

Why take a chance

 

i only add the highest octane..

 

If you can't afford to run 93 all the time. Why even bother owning a Vette?

 

Just for clarification, the computer doesn't recognize the octane rating, it hears the pre-ignition, (knock sensors), and reduces the timing based on that. However, you are correct in that because it does retard the timing during pre-ignition events, the engine power relative to no retaration of spark is reduced.

zo6vettepilot

 

I haven't run regular gas in my Vette yet. But I did with my 97 Z-28, with the LT-1. I ran a month of reg and a month of prem. gas. I got NO knock. The performance was down, no difference in the smoothness of idle, crusing at highway speed no difference. The interesting thing was that it ended up not being that much cheaper since I got better milage with prem than with reg. It was a 6-speed so my milage was always good. It averaged out to be about a mile per gallon difference. The computer will compensate for the octane so it will not knock.

 

I've done this before, cause I was curious, the engine felt very sluggish. I dont think it hurt anything though. Dont really think there were any "benefits" either as I think the MPG actually suffered, so it offset any savings of using cheaper gas.

 

Why though?

 

I didn't spend $50,000 on a car, only to run 87 octane in it. I drive my '99 coupe everyday, and will continue to run premium in it, regardless of price.

 

ahh someone I know works at a gas station and this black vette that always goes there gets regular everytime.. he goes it kills me why he would do that to the car!

 

You paid $50,000 for a 99 Coupe new. WOW!

 

I am far from a gear head, but I consider myself a very savy consumer. For instance I have never owned a Vette, but I will buy one soon and of course change the oil every 3,000 miles. But for the honda prelude I owned I didn't believe that 3,000 mile bs, I changed it every 10,000 miles, no problems. I am also coming out of a BMW 3 series which I never used premium fuel on. The first car I ever had was my grandma's 1964 thunderbird in 1989 (22,000 original miles at that time) with the 429 V8 option, now that car required 93 octane for sure, it almost vommited with anything else.
In college one of my business professors (in Texas) explained to us some of the hoodwinking in the gas industry. First off, the same tankers go around to the same gas stations, i.e. screw us if we think Chevron with Techron is really any different than Exxon or whatever. I never asked him about this, but I wonder if most gas stations just have one giant tank sending the same gas to all three pumps, or who knows if a gas station actually puts the right gasoline in the right tank. I assume we don't waste tax money paying some guy to spot test gasoline.