2014 Chevy Express 2500 with 6 liter V8 engine.
16,000 miles on it. Moderately loaded with solar panels on roof.
Daily driving around town 12.5.
On a trip, pretty much all freeway 16 to 18.5.
I tend to drive 70 to 75 so I think it might be a bit better if I slowed down, duh.
Only thing that I...