LT4 What octane fuel do you use in your LT4?

[lew]

What octane fuel do use in your LT4?

 

[FX GS]

Sunoco 94

 

[B17Crew]

Go Go Juice...

Sunoco 94

B17Crew

 

[lt4 gs]

Mobil...Shell.........BP....prem.....
Since I moved over here on the WSide of Mich.......I have had to detox my car and Corvette from Ultra94.........

 

[Tuna]

Whatever is the best premium I can get in OK for the price - usually 91. 93 is very hard to find in OK.

 

[all4c4lt4]

Shell 93

 

[twiget]

I ran 76, 92 octane. 93 is pretty hard to find in my area.

Jason

 

[lew]

Why not run 87 octane in an LT4?

I am kind of surprised that nobody so far admits to using less than 91 octane fuel in their LT4. LT1 engines seem to run well on 87 octane. I drove a 96 Impala SS for 8 years, and it ran fine on 87 octane, never any knock and never any knock induced spark retard on Autotap. The LT4 has slightly higher compression, but it has a knock detector that will retard timing and protect the engine if knock occurs. A Corvette engine would be more lightly loaded than an Impala SS engine, due to 800 lbs or so less weight and better aerodynamics. I read a comment in the C5 section in which a service tech stated that higher octane fuel actually causes more carbon deposits than regular, because of different additives. Given that 91 octane fuel costs about 20 cents more per gallon ($1.72 in my area) I would have thought someone would have tried lower octane fuel. Has anyone actually had a bad experience, i.e. engine knock or spark retard, while running fuel with less than 91 octane in an LT4 engine?

Respectfully,

Lew

 

[96corvetteLT4]

When I purchased my 'Vette 9 months ago, I used 91 octane for about the first 2 months. With escalating gas prices, I decided to try mid-grade 89 octane. I have been running it since then without problems. I have considered trying 87 octane, but have not done so.

 

[jack volkert]

Shell 93 in my G.S., highest octane i can find here in FL.

 

[sbu8999]

LT4 - Kwik Trip 89 (octane)

I use KwikTrip 89 octane (no lie, a Wisconsin based gas chain). LT4 w/cam does just fine, and I admit to driving it on the mellow side, even as a commuter. Between the cost per gallon difference, and that lonely MN troopers like to stop and talk to us cheeseheads when we cross the border, an easy drive on 89 is fine.

 

[froggy47]

91 is about all there is in Calif - unless you buy race fuel - 5 gal cans. You really don't get any improvement on a stock setup with higher octane.

 

[dcaatc]

Shell 93 Octane - No Problems!! To find anything higher in Southern Maryland is pretty hard - A few SUNOCO's scattered throughout Maryland with 94 Octane!

DCAATC
Dick Cox