Fuel Consumption at High Idle
 

I had the outfitter switch (cheap) fast idle installed. I used switch #3 (10A) and the BCP wire. It really works great and cost $75 for a professional mechanic to wire it. It runs a steady 1200 RPM and the EGT stays right at 415 in the manifold.

The question is – does anyone have any idea how much fuel per hour it will burn at 1200 RPM?

The numbers I've heard is 2 gallons per hour. I don't have any scientific evidence to back that up, but it seems to be pretty close on my truck.

I meant to reply earlier, sorry about that.

I can't remember the exact numbers, but high idle when the engine is cold uses alot more fuel than when the engine is warm. I want to say 1.5 gallons per hour when warm, but i will check tonight after the drive home from work.

I think the reference that tvsjr is talking about is that idling for an hour is like driving 33 miles. My truck when warm, no AC, and in park burns 0.5 gallons per hour. That bumps up to 0.8 gallons per hour when your are in drive with your foot on the brake. The 0.5 gph in park also jumps to 0.8 gph when you turn on the AC. I see no difference in mpg driving at highwat speeds with the AC on or off.

Check out the scangauge thread on this site. It is a great little tool.

WOW!! I'm glad I did it myself. Only took me 10 minutes once I got the upfitter switches in. Mine didn't come with them, but I found them online for $80 and put them in and set up #4 for the high idle. I don't know why, it just sounded cool. No reason for me to use it.