Hey guys. Just wanted to see how altitude should affect the timing setting on the tune of my truck. I run the 5.4 and am at about 1850 above sea level. thanks

 

I don't think you're high enough to try any timing change. I live at 2500 feet and I tried advancing my timing by only 0.25 degrees when I first got my programmer (it was an Edge then and still had canned tunes). I immediately noticed an unstable idle, the RPMs would not stay steady. I put the timing back to zero and the problem went away.

And, you'll find that if you live above 3500 feet, you might see 86 octane gas as the choice for regular. Altitude does reduce the tendency to "knock", which makes the lower octane appropriate, and if you use that gas, I wouldn't try advancing the timing there either.

- Jack