MPG Swing ?

I had an 1100 mile round trip to South Arkansas for Easter averaging 77 mph. Trip down computer said 22 mpg average. Trip back Sunday was 17.2 mpg. I lost about 90 miles on that tank. Any ideas why? I haven't seen a swing that big before. All considering, the only difference was temp changes and it should not have caused that much.

 

Tail wind verses head wind?

 

Trip down was probably a slight down hill overall. Trip up was probably slightly up hill.

 

what went down must have come up? Meaning different strains on the engine or running different rpms???

 

Did you guys stop at an all you can buffet on the way back?

 

Enter your starting point and ending point here to see what your route elevation change looks like. With an 1100 mile trip, it will take a minute or two to calculate and display the elevation change. Wind is also a big factor. The buffet thing too.

 

Wind and Hills have a pretty big impact.

 

Taking in-laws into consideration, did you have to drive any in-laws back?

 

After using the Elevation map that was provided earlier and taking into potential head winds and tails winds, I guess that is what swung the MPG. I just didn't think it would have been that big of a swing.

 

Temp plays a bigger part with these trucks than you’d think.