Dumb question. Have you hit the mpg reset option to re calculate the mpg?

 

Yes. I reset it every time I fill up.

 

I have a 2012 Ram 1500 QB with he hemi and stock 20" wheels and I get anywhere from 210-225 miles out of a tank which isn't very great!

 

What size tank do you have? I have the 32 gallon and can get around 350 or so maybe more before the low fuel indicator is written in the mpg till empty spot. I could push it, as I always have 7-8 gallons still in the tank after a fuel up.

 

24 gallon I think? something like that. I don't have a 32 gallon tank

 

Looking on the net I see that going from 55mph to 70 mph take approx. 30% more energy.
Just picked up a 2014 myself and took a country drive and averaged 23.7 mpg and that was with the wind blowin like a madman.
We di go throught a tunnel about a 1/4 mile long,so no wind basically perfect conditions and the guage jumped up to 35mpg