smokeywren

I'm a big fan of the 3.5L twin-turbo EcoBoost engine. In my 2012 F-150 2WD with 6-speed automagic tranny with tow/haul mode, 6.5' bed and 3.15 axle, the truck handles my 5k travel trailer (TT) without breaking a sweat, even when climbing steep grades in hills and mountains. And if push comes to shove so I must tow a heavier trailer, it still gets the job done. For one trip over the Texas Hill Country on a cool Spring day, my trailer weighed over 19,000 pounds and the EcoBoost dragged that trailer at 65 MPH without overheating anything in the drivetrain. I was severely overloaded over the GVWR, rGAWR and even the GCWR. but the F-150 never stumbled. MPG was awful, because when those twin turbos go to work, they suck a lot of gasoline.

Threads on this and other towing forums indicate there is very little difference in MPG with the 3.73 ratio than with my 3.15 ratio. That's probably because the tranny doesn't downshift as often and the twin turbos don't kick in as soon with the shorter legs. My 3.15 ratio works just fine, but so would a 3.32, 3.55 or 3.73. So be concerned with other options of the F-150 and don't worry about the axle ratio. For example, you want the max tow pkg, which requires the 3.5L EcoBoost engine and gives you the bigger gas tank and includes the 3.55 electronic-locking axle rear axle and other goodies.

Don't be misled by the advertised MPG of the 3.5L EcoBoost engine. You can achieve 20 MPG only if you poke along without using the turbochargers. My normal unloaded MPG is about 15 to 16 with mostly-highway cruising at 79 MPH on regular gas. Towing my 5k TT across the Plains at 65 MPH, I get about 10 MPG on premium gas. Hills, passes and strong headwinds reduce that to about 9 MPG. I would expect the 10-speed to get a bit better towing MPG because when it downshifts from 10th to 9th, the final drive ratio is still an overdrive ratio with long legs. When the 6-speed downshifts from 6th to 5th, that's direct drive with much shorter legs than when in overdrive.

I plan to order a new 2019 F-150 this fall, as soon as the order guide is available to the dealers. I will include the max tow package, and maybe the heavy duty payload pkg (HDPP) which includes the 3.73 axle ratio.

RubyRed Canadian

I have the 3.5 Eco and 3.55 ratio (max tow), but that's because I tow 25-30% of my annual mileage and my trailer weighs 8000lbs.

If I were in your situation, I wouldn't pay for the premium 3.5 Eco, since you won't be taxing your drivetrain.

Take the money you save and spend it on the little bit of extra fuel the V8 uses on day to day driving.

If you do opt for the 3.5 Eco, you will recoup a bit of the premium you pay for the engine when you trade it in, unless you keep your truck for longer than 6 or so years.

acdii

I believe when you order an HDPP with the 3.5 it does come with the 3.73 gears and I think that is due to the axle itself only coming with that gear ratio. It is a bit confusing looking at the order guide as the HDPP with the EB requires the Max Tow package.

chimmike

Not anymore. Apparently on 17+ it's 3.55.

Joe Friday

Can anyone tell me what the towing capacity is for the 5.0 V8 and the 3.5 EcoBoost with 3.31 and 3.55 gear options?

smokeywren

No, you have been misinformed. 3.73 E-Locker rear axle is part of the 2018 heavy duty payload pkg (HDPP). For 2018 models, HDPP is available with the 5.0L engine that has the 53A regular tow package, or with the 3.5L EcoBoost engine that has the 53C max tow pkg.

smokeywren

Towing capacity (tow rating) is GCWR minus the weight of the new truck, so it depends on exactly which new truck. For 2018 F-150 tow rating with the 5.0L engine and 3.31 ratio varies from 8,300 to 9,100 depending on cab, wheelbase and 4x2 or 4x4. Same truck but 3.55 axle varies from 8,300 to 10,100.

With the 3.5L EcoBoost engine and 3.31 axle, 10,400 to 10,800. With 3.55 axle, tow rating varies from 10,700 to 13,200 depending on the above factors plus with or without the max tow pkg..

GCWR and tow ratings for 2018 models are included in the 2018 RV and Trailer Towing Guide. Or for the upcoming 2019 models in the 2019 RV and Trailer Towing Guide. The ~40-page PDF files are available for download from https://www.fleet.ford.com/towing-guides/

Joe Friday

Thanks Jeff... I know the new engine/tranny will be different, but is yours a 4X4 and is the mileage you stated 'average' or 'highway only.' Thanks.

Gladehound

This statement is false for the new F150s and it's time to stop repeating it.

I have a 2018 SCREW 157WB HDPP with the 3.73 gears and the 3.5EB and 10-speed. I have almost 10,000 miles on it and am averaging 18.0 MPG (on the computer) so far since I bought it. That's mostly country driving with some highway, some towing and some city as well. I'm often over 20+ MPG on tanks that don't include towing and have a few hour long trips to soccer games. So MPG doesn't "suck". And my truck sits at 5,700 empty with the topper and bed mats - so not a light weight by aluminum F150 standards.

Regarding being "way out of it's power band". This is absurd. It's an absolute rocket with these gears and responsive at any speed!

Like whatever gear you want, but don't let your bias get in the way of providing factual information.

Gladehound

This is right off my truck in the signature. 3.73s are alive an well in 2018.