I am considering running 92 octane for the rest of the winter. In MN, all fuel has to have 10% ethanol. The past couple tanks I have noticed a fairly big drop 9in mileage. On my last 450 mile trip, I averaged just over 10 mpg. In the summer, I get just over 13 when not towing and driving highway miles. Would 92 octane help offset the loss of mileage from the 87 octane with ethanol, or am I just throwing money away? I believe the premium also has a 10% ethanol blend. The price difference was $.20 a gallon for the 92 octane.

 

Premium gas is not going to do anything for you since the 6.8 was designed for 87 octane. The winter blend can lower your mileage compared to summer but premium wont make up the difference. If you had a higher compression engine, have advanced the timing somehow or are running a specific tune through a programmer then higher octane will make a difference. Higher octane levels means the gas just burns a little slower so you can advance the timing or raise the compression safely without pinging or early detonation.

 

wasting you money. just think how bad your mileage would be on E85 which is 85% ethanol...

 

Im out in California and I busted that myth. Just took a 1260 mile round trip to Vegas and back, I averaged about 14mpg mostly highway. I tried running premium, the only thing I noticed was that acceleration was a little better, but with better acceleration you tend to step on it harder. I think of it this way, I didn't buy a V10 Excursion for saving $ on fuel, I knew it was thirsty and got it as a safe family vehicle for my wife baby and I. And to tow toys. And to **** off LIBERALS. Besides the gas, the Excursion is an awesome vehicle.

 

Actually, in theory you should get slightly better mileage with lower octane fuel. As said above, premium is just a waste of money in a stock V10.

 

I only run 87 here in PA....not as cold here but I can still buy gas without ethanol, Mike.