swayse

Tow haul will lock the converter, and it will shift into overdrive.

Shan

Acceleration requires power... You don't hear "It towed great!" and "got less gas mileage than such and such" in the same sentence for no reason. Odds are if you had both trailers and the same truck you'd notice you were moving away from red lights/passing a lot quicker than the truck that got better gas mileage.

In other words... slow down.

Cord

Maybe it was lugging in 6th gear? 5th might have given him a bit more rpm, reduced the boost and improved mileage.

swayse

Truck won't let you lug it, it'll downshift way before it needs to, unless you lock it into 6th. I've only pulled a uhaul trailer with a vw bug on it, 02 tdi, but it did fine, and did ok on fuel. If I compare it to my 06 dodge cummins pulling a uhaul trailer with a 02 Z06, very close mpg.

Rob1334

So explain what the big gain is locking the converter when towing, it seems I have always gotten better mileage not using tow haul mode.

Pulled our 22ft boat this summer to the lake and got 13 with the cruise set at 72, didn't pop out of 6th the whole way there up and down some decent sized inclines. Waiting for our 20ft enclosed with 5ft V to show up, gonna load it up with our sleds and pull it down the highway a ways and see what it does... would love to pull the trailer this winter if I can do it cheaper than our diesel..

93Cobra#2771

iTrader: (2)

When the TC is locked, you are at maximum efficiency. Unlocked, it is losing some efficient when it I slipping. But, that same slipping is used for better acceleration from a stop, etc.

brucesears

With my '09 Lariat with 5.4 the best I ever did was 14 mpg towing an 18 foot boat. The new '12 Platinum with Ecoboost gets 14.5-15 mpg pulling the same boat. Neither was going the speed limit.

sqidd

Towed a 28' car hauler with a car and equipment, I'm guessing 4000#.

At 80mph was getting 8pmg in 6th gear. Then I put it in 5th and got 10mpg.

justjimmy

What the heck are you doing towing at 80mph?

There ARE others on the road.

Rob1334

When you get rolling on flat ground... like say interstate of eastern MT.... you are better off doing speed limit with your laod than to create a slow moving hazard for people to have to jump around you...