Fuel Question

[tone357]

I read in another post that a guy was using 87 octane fuel, but he didn't mention which engine. Can you run 87 in a 8.1?

[dewfpo]

I read in another post that a guy was using 87 octane fuel, but he didn't mention which engine. Can you run 87 in a 8.1?

 

Yes you can. It was designed for 87 octane. I however, find that when I use 85 octane (high alt. equiv. of 87) that when I initially start the engine I get a loud, single rap or knock on startup. I'm fairly confident that it doesn't hurt anything but I don't like that so if I use 91 octane, it does not do that.

 

DEWFPO

[StoneyPgh]

You sure can. I run 87 octane in my factory stock 8.1L engine,

even when I pull my 8,000# fifth wheel camper.

[xwire]

87 is the only thing I run in my 01, I even find I get better fuel mileage then compared to 93 by 1-2 MPG

[pennzoil29]

Yes. My ex-brother in law did intil he peeled open the whole passeger side of his '02 on a telephone pole. Looked like someone opened up a can of sardines.

[Roofer]

Buddy of mine tries to claim 5-6 mpg better with premium. Anyone else ever heard this line???????

[wellinghurst]

Buddy of mine tries to claim 5-6 mpg better with premium. Anyone else ever heard this line???????

 

5-6 sounds ridiculous-maybe 1-2. I get 1-2 better in my 6.0, but my tune requires it. All it takes is 1-2 better and it pays for itself.

[tone357]

Buddy of mine tries to claim 5-6 mpg better with premium. Anyone else ever heard this line???????

 

5-6 sounds ridiculous-maybe 1-2. I get 1-2 better in my 6.0, but my tune requires it. All it takes is 1-2 better and it pays for itself.

 

 

OK, which is it better mileage with 87, or better with 93. We've got contradictions here.