GringoEd

My 2014 XLT SuperCrew has 5.0 L Flex Fuel engine. I have used 87 Octane Regular Gasoline exclusively, and it runs great. If 87 Oct. was not available, would there be any issues or engine damage caused by using higher octane fuels, such as 89, 92, or 93 octanes? Thank you!

Crash89

None whatsoever

87 is the minimum octane required.

strokin7.3

I run 93 exclusively in my truck. You actually gain a bit of HP even with the stock tunes just by switching to the higher octane fuels.

You could also run e85 through there but don't be shocked when your gas mileage tanks.

GringoEd

Thank you for the information. Really lovin' this truck, and didn't want to do anything that would harm it.

503PDX

Im not so sure about using higher grade fuels when the vehicle calls for regular unleaded. Unless you have upgraded the software you usually dont see any gains from using premium vs regular fuel. From what I hear, E85 might give you a little more power with less MPG.

strokin7.3

Factory tuning will automatically adjust timing and things when you run higher octane fuels.

In one of the MPT videos they show a dyno chart of a stock tuned truck on 87 and then a stock tuned truck on 93 and it was a 8-10 hp difference.

I know before I put the tunes on my truck I ran a tank or two of 93 with the crappy stock tuning and it felt a touch peppier. I also picked up over 1 MPG.