Have to use 93 Octane ?

I have used 89 octane in my 96 for years and no problems

The way gas is right now everything sparkknocks :-( even in our 98 Honda accord which recommends 89 octane pings like crazy!! I have tried every brand in town and they all do the same.

Mike

2000 coupe 1989 coupe 1990 rustang 1998 Honda 1977 hobie skateboard (3 different models ) 1970 Yamaha R-5 1985 john deer

IIRC, 91 octane was 'premium' in 1992. Few stations out here carry 93 octane fuel.

You might save a dime by re-checking section 6 of the owner's manual. The only decals on my cars say, "unleaded." (The C4/L98 was a Florida car, the C5/LS1 was first sold in California.) No mention of "premium" fuel in either owner's manual. Both manuals recommend 91 octane for regular use but permit 89 and 87 octane with reduced performance. 87 is the minimum for either car.

The C4 manual does have a firm 'gasohol' restriction for no more than

10% ethanol or 5% methanol. The C5 book says ethanol blends are OK but no methanol.

I've run 89 octane on the highway in my L98 and in rental C5s. I tried

87 octane in the C4. I didn't audibly knock but there's some combustion roughness (felt & sounded lean). I've not run 89 octane in this C5 but will try it on the next long trip.

Try this: Last night I filled the C4 with premium at $3.539 per gallon. It cost 21 cents/gal. more than regular. That was only 6% more than regular -- a mere pittance -- not even pocket change. It's a bargain since the C4 gets about 10% better average mileage than does mama's wheels does on regular.

Besides that, my leader (in this morning's paper) said, "there's no gouging at the pump!" No one poked me with a stick at the pump so he must be right. I feel good by having faith in my leader.

Gotta get the C5 & mama's barge to the station before the price goes up again.

Enjoy that LT1!

-- PJ

You can use the lesser fuel HOWEVER..the knock sensor will detect it and retard the timing to eliminate the knock...you should not hear a knock or engine ping but since the timing has been retarded..performance will go downhill and the Vette will no longer be fun to drive. SO USE THE SUPER PREMIUM and enjoy the car the way it was designed to be driven. Better for you & better for the Vette.

under normal driving, its not going to make that much difference.

my2¢