5.7 can do it!

[vincentw56]

I think the 70mph is the secret. I normally averaged around 16-17 with normal mixed highway/city driving. However, twice now I've driven from the Dallas area to Bloomington, IL and tried not to exceed 70mph and was able to average 21mph on both trips. The other trip I took up there I drove 80 when I could and only got 17mpg. So, it can be done, but you got to keep your foot out of it.

I think the secret is to not have 3.92 gears, too. LOL. That's why I will never see those numbers.

 

[BowDown]

I think the 70mph is the secret. I normally averaged around 16-17 with normal mixed highway/city driving. However, twice now I've driven from the Dallas area to Bloomington, IL and tried not to exceed 70mph and was able to average 21mph on both trips. The other trip I took up there I drove 80 when I could and only got 17mpg. So, it can be done, but you got to keep your foot out of it.

It appears to be that way with my truck, below 70 mph my fuel economy drops substantially, 1500-1700 rpm seems to be the best economy and that's around 70-72 mph. I've been as high as 22.5 - 23 if I can keep my foot out of it and stay at 70-71. Above that I drop to around 21-20. 65-68 nets me around 20 mpg as well

 

[Mountain Whiskey]

It appears to be that way with my truck, below 70 mph my fuel economy drops substantially, 1500-1700 rpm seems to be the best economy and that's around 70-72 mph. I've been as high as 22.5 - 23 if I can keep my foot out of it and stay at 70-71. Above that I drop to around 21-20. 65-68 nets me around 20 mpg as well

Come on. Not pushing front axles and gears down the road is your secret to better milage. Lol!

 

[BowDown]

Come on. Not pushing front axles and gears down the road is your secret to better milage. Lol!

well, that front axle aint helping me get from point A to point B

 

[Code2medic]

I think the 70mph is the secret. I normally averaged around 16-17 with normal mixed highway/city driving. However, twice now I've driven from the Dallas area to Bloomington, IL and tried not to exceed 70mph and was able to average 21mph on both trips. The other trip I took up there I drove 80 when I could and only got 17mpg. So, it can be done, but you got to keep your foot out of it.

From middle Tn to Chicago the north side to be exact is 506 miles exactly and 1 tank gets me there with ease. 7 over the posted limited is all I do

 

[boogielander]

This was last weekend. 3 day trip with about 100 miles of offroading - high speed dirt road runs, low speed crawling through rock gardens and tight trails, and some idling while waiting.
freeway speed was put at 65-70 MPH

Hand calculation turned out to be 15.7 MPG. talk about computer vs hand lol