Saw this in "Consumer Reports" the other day. They ran an '06 Explorer at 55mph and got 24mpg, then upped it to 65 mph and got 3mpg less. At 75 mph, they lost another 3mpg.

The motto of the story is....."Speed Kills" [your fuel mileage]

 

I got better than 17mpg averaging 80mph on my last highway trip (about 400mi round trip). I was expecting 14, maybe 15 so I think I did quite well.

If you can tolerate 65mph for 1100mi more power to you.

 

I just returned from vacation and I averaged 16.7 to 19.0 mpg and I won't complain. I drove 75 - 90 mph & that's with and without the cruise control. I also drove over quite a few mountains,

 

I agree with the "synthetics everywhere" post. Fill all tires with Nitrogen. It's probably anecdotal, but it might help. With or without nitrogen, proper inflation is the key to improving gas mileage. Motorists can improve gas mileage by 3.3 percent simply by keeping their tires properly inflated, according to the U.S. Department of Energy.

I had less than 10K miles on my '05 Lariat 4x4 last fall when we took it to WY for a hunt. 3500 miles round trip. We averaged 18.6mpg and I never drive under 70, 80 is more like it. Our total gas bill was $566 split 3 ways. Immediately before that trip we changed everything over to Amsoil: motor oil, front/rear diff, transfer case, entire transmission. I used Royal Purple's Purple Ice in the radiator with 6 quarts of antifreeze and the rest distilled water. Dumped a bottle of Techron in the tank too.

I know, it's all snake oil, but I wanted to see if it would make a difference and it did. When using MC 5w20 blend and whatever came in the truck everywhere else, I averaged 16.8 on a trip to Illinois.

Whether brands of gas make a difference, I do not know. All I use is BP/Amoco, Shell, and Chevron.

 

Use your cruise control and do the limit or a couple over will help you out alot mileage wise.