LT4 LT4 fuel

[Dean Barker]

I recently purchased my first Corvette, a 1996 red/black LT4 6 speed coupe with 31,000 miles. I am thinking of occasionally using a tank of 89 octane fuel with ethanol to keep things clean. I don't think our Iowa premium fuel has ethanol in it. I have run the Buick 3.8 Liter engine over 320,000 using ethanol with no problems with injectors, pumps, etc. Opinions, please.

 

[lew]

Dean,

I have been running my LT4 on 89 octane without any problems. There has been no discernable engine knock or spark retard. When I get the time I am going to put the Autotap on it and check for spark retard, then report my findings back to the group. IMHO, 89 octane gas is not likely to hurt your engine because the knock detector will pick up the knock and retard the timing.

All of the gas stations that I have been to in this area have ethanol labels on all of the pumps.

Lew Fischer

 

[vetteguy]

Welcome Dean, nice color combo. My car says premium unleaded and that is what I will use. Good Luck, Guy

 

[wx briefer]

By federal mandate, all vehicles in the USA must be able to be certified on 87 octane. However, since good performance means advanced timing, manufacturers find it necessary to use knock sensors to retard timing for testing on 87 and encourage use of higher octanes in the owners manuals to allow advanced timing for the better performance.

 

[WradDad]

Dean,

I used 89 octane for about three tanks-full. Maybe it was just my imagination, but I felt a slight bog or hesitation when accelerating away from a stop with anything less than 3/4 throttle. I switched back to 91 (best I can get) and it went away. I'll stick with the manufacture's recomendation.

Hey, maybe we're related!

Barry Barker