Ecoboost 3.5 Towing MPG Sucks

Grodyman wrote:
Hi all, back after a couple years without a RV......I jumped back in with a Passport Ultra Lite 153ML, GVWR of 4500lbs.

I just returned from picking up the trailer and pulled it with my 2017 F150 3.5 Ecoboost with 3.55 gears.

I was astonished to pull such a lightweight, aerodynamic trailer and the best MPG I got was 10.2 MPG. I went as low as 8.5 MPG.

I could have done better than that with my F250 with the 6.2 V8.

I am surprised how dreadful the towing MPG is with truck considering the overall weight of the truck/trailer combo is a couple thousand pounds lighter than I usually travel.

Unloaded this truck is great, but if you are on the fence about a F150 and a F250, go with the F250 gasser all the way UNLESS you drive a lot of unloaded miles.

The truck had plenty of power, no issue there, but I simply cannot imagine pulling 7K-10K lbs with this truck, the MPG's must be around 5.

My current range is about 250 miles pulling this Ultralight, given the fuel tank size. So, essentially, adding an ultralight trailer dropped my MPG nearly in half. Not what I expected.

Gman

the biggest factor with mileage when towing a trailer is wind drag which is a square law function. Weight doesn't affect towing mileage that much unless you are constantly going up and down hill or accelerating and braking. It's the frontal area. As an example I have a 7x14 cargo trailer 5K lbs loaded and a 35Ft 9,000 TT. the difference towing mileage between the two is at best 1 to 1.5 mpg and the 7x14 has much less frontal area than the big trailer. and even the 7x14 when compare to the highway mileage unloaded is about 40% less than unloaded highway mileage. Or towing mileage is about 60% of unloaded highway mileage. And unloaded avg speed is at least 15% faster than my towing avg speed!

your towing a barn door down the highway with a Cd of near 1. By comparison your truck is a garage door with a Cd likely aroud .35
That is the wind resistance of the truck is about like 1/3 of a garage door while the trailer is like a big barn door.


towing speed is one of the biggest impacts on your mileage given the square law relationship of wind drag. 10mph can make a noticeable difference.