6.8L V-10 Ford fuel question???

87 octane. That is all I have used and it runs fine.

page 124 of the owners manual...

Regular unleaded gasoline with a
pump (R+M)/2 octane rating of 87
is recommended.

Tryed supreme with no difference, use regular always.

Have a 2005 four Winds with a 2004 f-450 V10 runs fine with 87 octane but better on 89

My V10 is supposed to run on 87 octane, E85 is not to be used.

I don't know about the Chevies, but anything less than the cheap stuff is actually bad for the Ford V-10s, unless the V-10 has a custom-programmed tune to be able to have the correct valve timing for the higher octane.

I've fiddled around with grades of gas with my old F-150. The expensive stuff got me the same MPG as the cheap stuff. My new F-150, I have been messing around with E85, and it does seem to have a little bit more HP (butt-dyno measurements), but MPG numbers are not a pretty sight.

My take: Use the cheap stuff, or see about a tune and programmer that can make the engine use the higher octane fuel. I've read about people finding that the MPG gain from the higher octane fuel tunes more than offsets the higher pricetag. However, one's milage will vary, and tunes can differ.

Oh and use tunes at your own risk. They can damage an engine.

mlynds wrote:
I found mine gave better mileage and more power with the higher octane fuel

While I found (two different units with different variants of the 6.8 V10) no difference.

87 in mine too

I likes regular and lots of it.:)

I found mine gave better mileage and more power with the higher octane fuel