Community Forums

aknavy · 03-29-2018, 12:40 PM

So, I've used my truck almost exclusively for towing since initial break in. Currently making a trip without the trailer, and reset the computer MPG tracker - I know it's not perfect, but here's a surprise -

40-55 mph = 16-19 mpg

55-70 mph = sucks, not sure how bad, but would guess 12-14 mpg

75-90 mph = 16-19 mpg

Seems the sweet spot for mine is 1900-2100 RPM.

I was surprised to see better mpg above 75.

60sumtin · 03-29-2018, 01:22 PM

Do the math using actual distance between fill ups and fuel needed to refill. An increase in fuel milage the faster you go seems unlikely.

Traildust · 03-29-2018, 04:50 PM

I am not sure about the trip computer on the new trucks but the one on my 02 Lariat 7.3 is a joke. I always do it the old fashion way, fill it to same spot each time divide miles driven by gallons used. The good old 7.3 CC,LB, 4X4 with a 3.73 limited slip 6 speed gets 18 to 20 highway 14 to 17 in town.
Bill

Old-Biscuit · 03-29-2018, 04:53 PM

According to my 'Lie-O-Meter' I get 15-16 mpg combined

Real life.......not too concerned cause I drive a TRUCK

aknavy · 03-30-2018, 11:38 AM

I've checked the mileage manually, and it's consistently 1-2 mpg less than the computer. So, I'm assuming that this is carrying over to the current computer calculations. While not the exact mpg, it is close, and it seems to be an interesting trend. My fill ups on the 700 mile trip, while not calculated, seem to bare this out as well.

mrgrayaz · 03-30-2018, 11:43 AM

if your diesel, My guess is you regenned during your 55-70mph and bombed your mileage. Makes zero sense for it to be lower then the high speed.

Last 85mph run we did ~120miles we got about 15mpg avg. Actually worse mileage then my old 6.0 truck at similar speeds, but lot more power and emissions junk.

the 6.7 has the power to do it, but your in the boost.

caryt · 12-06-2018, 01:38 PM

I have a 2015 6.7 F350 srw, sweet spot with the 3.55 gears is 1700-1800 rpm or 75-80 mph in the flats 20mpg's, 23k mile adv is 16.8 mpg

heySkippy · 11-06-2019, 04:40 AM

Last weekend I drove from Sarasota to Key West and back with a side trip to the port of Miami on the way down. Mostly very light traffic both ways with lots of cruise control @ the speed limit driving over 750 miles. Admittedly almost perfect conditions, got 21.5 MPG in my 2012 F350 6.7 diesel.

I think the absolute perfect condition for this truck would be about 45 MPH on cruise control. There were stretches on US1 in the Keys where it appeared to be just coasting with no effort at all.

Gammel · 12-28-2020, 11:10 AM

"I've checked the mileage manually, and it's consistently 1-2 mpg less than the computer."

Roger that. Go Navy!

That said the puter is consistent at least for a rough gauge. While science does say that going faster will result in poorer mpg I am pretty sure that my 3.5 Ecoboost does better at 75 than 70. I'm not a rocket scientist, or even a mechanical engineer, but I do watch that mpg display rigorously and that's my story!