VetteGoVroom82

Hey guys, what's going on? I was just wondering what type of fuel (premium, etc) that the C3s use? Is it the same for all years? Also, what determines what type of fuel an engine requires? Thanks everyone!

-Paul


[Modified by VetteGoVroom82, 1:26 AM 1/27/2002]


[Modified by VetteGoVroom82, 1:36 AM 1/27/2002]

Mark69

The fuel an engine requires depends mainly on its compression ratio. The higher the compression is, the higher quality fuel it needs. The compression ratio in corvette base engines was lowered by GM from 10.25:1 in 68-70 to 8.5:1 in 1971-77 in order to prepare their cars for the use of unleaded fuel. This is why C3 corvettes before 1971 require at least premium, some of them (those with 11:1 or 12.5:1 CR) even better fuel. I guess you should be able to run the 71 and later C3s on regular gas. I only have a 69, so I have not tried it. ;)

marky mark

93 octane for anything over 9:5 to 1 comp ratio is a good yardstick I think.

Larry B.

Chevrolet made the switch to allow low lead 91 octane to be used in 1971 as leaded fuel was phased out. GM owners manuals call for at least 91 octane even in later models which will compensate for lower grades of gas. I use 93 Amoco. Since Corvette are a performance vehicle I would only use premium. If you are trying to save a few cents in gas then a Corvette should not be your car of choice. I even use 93 in our mini van. :D


[Modified by silvervetteman, 5:10 AM 1/27/2002]

Golden80

A guy in my neighborhood who used to own a Mid-year always ran leaded race gas. I loved it when he'd pass the house and I could smell that 2.50/gallon exhaust!

Matt