2015 Ford 250 diesel MPG

[Moflash]

Originally Posted by Howard L.

Chevy Duramax. About 1000 mi per gal. Normal driving. Dealer told me, You use much more at idle. I would think the Ford would be the same.


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This is about right for the Ford 6.7 diesel also.


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[tqflightdoc]

Now currently on a trip across the USA. 2020 F250 6.7L diesel with 10 speed transmission. Pulling a 25fb Airstream Classic, weight approximately 750 pounds, Propride hitch. Just myself, my wife, and a Bernese Mountain Dog, with about 800 pounds in the the truck bed.
Without the trailer, at 70 mph, 20 -22 mpg.
With the trailer, at sea level, flat terrain 15.3 mpg in tow mode, 16.5 mpg in normal mode. We just drove today from Santa Fe to Mesa Verde. About 260 miles, through the mountains, two lane roads, average speeds 45-65 mph. Many times in 8th or 9th gear. Average altitude 7000 feet. We got 13.7 mpg, using tow mode.
I asked a Ford dealer why one gets better mileage without the tow mode, also is there any issue in not using the tow mode? I did not get a definitive answer on either question. Anyone with answers to these questions?

[Capt who]

I know this is an old thread but you asked. I use tow mode when towing my 25FC. I think the Tow mode is for when towing a lot more than an AS. I may try the normal mode next time out and see how it does. I will also keep an eye on trans and eng temps. I will still use Tow mode in the mountains

[tqflightdoc]

Thanks. I just camped next to a Diesel engine mechanic. He Thinks the two mode is designed for 15,000 lbs and up trailers, and does not think there is any damage to not using it with a 7500 lb trailer.
He thinks the tow mode, besides changing shift points, also boosts alternator output, which is costing mileage.
Today we drove from Moab elevation 4100 ft, to just south of the Grand Canyon, elevation 7000 ft. We used tow mode in the hilly areas, about 1/3 of the time. Mileage 14.0 mpg.