Martian

SCORGE

Hey! There's Scruffy

ifallsron

I can tell the octane difference in my Riviera but not so much the F-150. I also have Flex capability although I've never used it so I'm thinking the difference is negligible.

SCORGE

The only car I see a small difference with Premium....is the Wife's Escape. Seems to get a few more miles per tank. (According to the ever accurate das readout)

Martian

Sounds like the MPG gain % probably won't be higher than the price % increase, though

SCORGE

Definitely not. 10 extra miles per tank...not worth an extra .25 per gallon
Besides....her book says 87...so I use 87.

PawPaw

Slight improvement in performance and fuel mileage running 93 octane Shell...not worth the extra 60 cents per gallon over the 87 I usually run.

WXman

On the F-150 specifically, the HP goes up. I'm pretty sure I saw dyno results from a guy with a stock truck on 87 octane compared to premium (93 I think) and the dyno did show a bump in horsepower.

If you think about it, it makes sense. These 5.0 flex fuel engines are designed to sample octane with each fillup and adjust accordingly, and E85 is much higher octane than regular so your power should go up as octane goes up and the ECU compensates.

On the Mustang, I think it was the V6 engine that was rated at two different power levels. The full HP was with premium fuel, and the car would run regular at a reduced power. It was even in the owners manual.

We are increasingly seeing cars and trucks built this way now days. For MOST people, they are wasting money with premium, but in a lot of cases it's not a waste. Really I think it comes down to the needs/desires of the owner and what you're using the vehicle for.

Speedfreak400

I have run several tanks in my Tremor and there is a noticeable difference in drivability and performance with no change in MPG if driven the same.

WasatchSkier

For sure, I am aware of that. Our ethanol free gas out here is usually 88 octane, which should be about the ideal fuel for the 5.0.