What's the best mph. For best mpg

[Trackerforsport]

What is a good speed to keep to get the best mileage on my truck ? 2 inch TT lift and 31s mud tires.

 

[Newfy Trac]

At at 76mph average over 200 miles, got 16mpg.

At a 62mph average over same 200 miles got 19mpg.

33' tires with a 4.10

 

[colintrax]

45~50mph. Get an ultragauge if you're serious about trying to get the best MPG.

Every vehicle gets best mpg at the lowest (sorta) speed in the tallest gear.

 

[Trackerforsport]

Ok thanks guys

 

[01STrunner]

I'd say 47-50mph. Its still low RPMs but not dogging the transmission and not constantly asking for a downshift.

 

[429CJ-3X2]

Every vehicle gets best mpg at the lowest (sorta) speed in the tallest gear.

Not true. Every engine has an rpm range where it runs at/near peak efficiency. (Think torque, not horsepower.) That's where you want to run. Find the lowest speed you can maintain on moderate hills with the least amount of extra pressure on the gas pedal.

My '74 Ranchero with a mild 302 and 2.75 gears got better mpg at about 70 mph than it did at 55. I had to get into the gas too much on the hills at 55, but it would maintain 70 on the hills without giving it much more gas. With a built 460 and 3.50 gears, it got better mpg at a lower speed. Of course, with the 460 it was a lot more fun to drive, and gas mileage wasn't a big concern. Still the original stock 302 w/2.75 gears got 13.5 mpg when new. 1974 and '75 were probably the worst years for mileage. The built 460/3.50 gears got 12 mpg. I traded 1.5 mpg for 3 times the horsepower and tons more torque. Good trade in my book!

 

[Boshka]

In Aug I did a road trip 300 miles each way with about 850lbs of ppl and the bed full of another 300 or so lbs of crap.
I averaged about 19.5mpg on the way down and back. That was pretty much with the cruise stuck at 73mph all the way there and back. There was about 15miles of stop and go city driving mixed in, but otherwise all highway there and back.