I have 2001 F250 SD with 5.4L, manual trans.

The book says to use 87 octane.

I live in Colorado, altitude about 5300 feet. I do NOT tow anything. Has anyone experienced problems with using 85 octane?

Is this engine "happy" with 85 octane? Can anything bad happen if I use 85 octane?

Lee Carkenord

 

I am in Utah at about 4,000 and have a V-10. I have run it on both 85 and 88. I couldn't notice a performance difference, but I think I am going to stick with the 88 for the extra 10 cents a gallon.

ERIC

 

Although ford recommends 87 octane,I think you can safely run 85 octane in your situation for a few reasons:
- If its not pinging, all is fine.
- The computer can compensate for this mostly.
- I 'think' i heard somewhere that at higher altitudes the combustion properties of 85 octane are similar to 87 at normal altitudes.. (something to do with lower pressure). I don't know the science behind this statement or if ts true or not. I guess I probably shouldn't repeat 'hear say' but figured I'd mention it to see if someone more knowledgable can shed some light on this.