So, I've now had my 2015 F250 6.7 Diesel for about 2 weeks and I just turned over 1000 miles (damn I love driving this truck). And, I'm dying to find out if my mpg experience coincides with any one else's experience who has a similar truck. With no load I am consistently getting right at 22.5 mpg at 70 miles per hour. With all in town driving and no load I'm holding right at 15 mpg. And I've noticed something else that seems odd. I'm actually getting a little worse mileage at 60 and 65 than I do at 70 miles per hour. What is going on there? Do these engines get a little better mileage as they get more miles on them?

 

Bump to top

 

I bought a (new to me) 2013 F250 6.7 on Friday. On the drive from Houston to Dallas I was getting around 18.5 while driving around 70-75 MPH. Over the remainder of the weekend I drive another 500 miles or so, highway and city. MPG dropped into the 16s.


Never checked the difference between 60, 65 and 70 but now I will!

 

My '11 will consistently get better fuel mileage at 65-70 mph then at 50-60. I suspect that the engine rpm is in a better efficiency range then when at a lower rpm. If I go up to over 70+, then it starts dropping off some again. Wait until winter grade fuel hits your local stations and then watch it drop off some.