93Cobra#2771

iTrader: (2)

Yep. And 1650 rpm is a good enough spot to pull about anything except heaviest trailers. I run 3:55s and really would like that extra couple hundred rpm to keep from downshifting into fifth.

strorg

Sorry to be such a newb but, well, I'm a newb. At the risk of looking like I'm hijacking this thread, would somebody mind explaining how the gear ratio affects towing.

Thanks...Tom

Norotso

http://www.trucktestdigest.com/axle%20ratios.htm

http://www.forconstructionpros.com/a...ve-performance

http://www.hardworkingtrucks.com/und...g-axle-ratios/

Google is your friend.....

frieed

I'm towing about 8000# w/3.55's (actually closer to 3.44 since I put 33" tires on).
At 65 mph the truck spends most of it's time in 6th. This past weekend I had about 7200# and on a 9 mile grade of 6-7% it would downshift to 4th and sit right at 2700 rpm and pull like crazy.

strorg

As is this forum.

Tystevens

I'm very happy with my 3.55s towing a 6500 lb travel trailer. Tows great -- easily stays in 6th gear on flat roads and up small inclines. Downshifts to 5th for moderate inclines and usually holds that gear. Only needs 4th for the steepest stuff on the interstate. And it gets good freeway mileage unloaded.

strorg

Sorry, Norotso, for being a smart-alec. Thanks for the links!

willieboy

I had an 2013 Lariat SCrew HD Payload + MaxTow 2wd with the 3.73 limited slip that routinely got 18.5mpg cruising the highway at 72mph, about the same as my brothers truck (just like mine except 3.55 maxtow only). Go to 75 and it started to drop pretty fast, but that is a aero problem, not gearing. Towed my 10K fifth wheel in 6th gear at 62mph. It would down shift to fifth to climb hills and maybe 4th once in a while. I would get the 3.73.

zx12-iowa

A 3.31 Eco will out tow the 5.4 with 3.73 gears all day and also a 5.0 with 3.73 gears. So a 3.73 is always the best towing gear it's often not Needed with the Eco due to the awesome diesel like torque curve

smokeywren

I'm a firm believer is having "enuff truck" for your max load. So to tow a 29' TT with an F-150 EcoBoost, you need the HD Payload pkg so you don't exceed the GVWR of your truck when towing.

The HD Payload pkg includes 8,200 pounds GVWR, the 3.73 limited slip rear axle and the max tow pkg (towing mirrors and intregrated trailer brake controller (ITBC)). That's about 500 pounds more GVWR than with the max tow pkg, and 1,000 pounds more GVWR than the standard F-150. No, you cannot have the electronic locking rear axle, and no you cannot have a 5.5' shorty bed with the HD payload pkg. So a SuperCrew will have "Posi-Traction" and the 6.5' bed. That's a shorty in the SuperDuty world, but it's the long bed in an F-150 SuperCrew where the tiny little 5.5' shorty bed is available without the HD Payload pkg.

Dealers don't keep the F-150s with the HD Payload pkg in stock, so you'll probably have to order it and wait 6 to 8 weeks for it to arrive at your dealer's store. So plan ahead.

With the EcoBoost engine, there are no significant disadvantages to the 3.73 axle ratio. Owners report about the same MPG I get with my 3.15 axle ratio, whether towing or unloaded. The limited-slip rear axle works fine after you learn how to use it. I prefer my e-locker rear end, but I've made do with a posi-traction axle for dozens of years.