5.4 vs 6.7 towing test

[Randy_270]

So this weekend I got to test out the towing ability of my 2011 f350 that I just got. Everyone keeps saying that the 15.8mpg average I'm getting with about 90% highway is normal but towing the same 4500 pound trailer I'm getting about .5 mpg better than my sister and brother inlaw's 07 f150 5.4 doing the same route, same weather conditions too. I get about 9 doing 60mph while my brother inlaw gets about 8.5 mpg doing 60mph both hand calculated by me. Also my truck runs in 6th gear(1500 rpm) while there's doesn't have the power to hold 4th so it runs in 3rd gear (2500 rpm). That just doesn't sound right to me? Someone either tell me this is normal or I have a problem with my truck. My truck still has tons of power and easily pulls the trailer like its not even there.

[Painted Horse]

It's normal.

My truck doesn't get much better mileage than my previous 6.0L trucks did while towing. It does get better mileage at cruise on the highway empty.

Stop and start will eat your mileage fast.

Weight doesn't m to make a big difference, But wind resistence does. Large trailers with more wind drag will give worse mileage than just weight alone.

[dieselmatt]

I'm interested in seeing the responses.

[Randy_270]

Painted horse, you are comparing diesel vs diesel so I would understand little difference but this is gas vs diesel so you would expect more than a .5 mpg difference. Most fuel mileage posts I've read about towing, most people are recording 9-11 mpg towing 10+ thousand pounds where as I'm getting 9 towing 4500...

[TaserX]

How many miles do you have on your truck?

[cthaeffner]

I pull a flatbed all the time that is 4-5k and get 14. When I hook up to the enclosed or camper that weigh about the same as my loaded flatbed I get 10. It's all in wind drag. I do agree with you though. We should be getting better mileage then the 5.4 working its butt off.

[Randy_270]

My truck has a little over 37,000 miles and finally someone sees my point about the fact that a 5.4 running at almost 2500rpm is using only slightly more fuel than my diesel running at 1500rpm in the roughly the same conditions.

[Dave]

Put some weight on that trailer and hook to the 150 with the 5.4.

4500lbs is nothing

[Moflash]

Pulled my 28ft Airstream(7-8k lbs) 2200 miles on mostly flat terrain and was 13.4 avg on the gauge.

[BIG Laing]

There are so many variables here, I don't know where to start.

Truck weight difference 8500lbs compared to 4000 or 5000 (?)

Gear ratios, Tire size, Lift, gas vs diesel, areodynamics, extra emmisions crap we have on 6.7 (Regens Kill MPG).