Forum Discussion

hayesdt's avatar
hayesdt
Explorer
Feb 16, 2015

3.55 or Other Gear Ratio for F150

I have towed my Springdale 28 ft travel trailer (around 7000# loaded) for the past ten years with a 2004 Ram 1500 Quad Cab 4WD with a 3.92 axle ratio (tow rating was 8700# for the truck as equipped in 2004). Also, I always use Tow/Haul when towing and actually only tow the trailer about 3-4 times per year for a grand total of under 2500 towing miles annually. Never had any problem towing my trailer with the truck -- seems well matched. But at nearly 12 years of age, and though the truck has only 57,000 miles on it, I'm just no longer confident with it -- too many MAJOR expenses the past 2-3 years. So I'm looking at selling/trading the Ram and buying probably an F150 5.0L V8 Supercab Std Bed 4WD.

Just wondering, though, as I'm assuming a 3.31 gear ratio (9100# tow rating) would not be as desirable for towing the kind of weight I'll be pulling, whether I can get by easily with the 3.55 gear ratio (9200# tow rating) with the new F150 as opposed to the 3.73 gears (11000# tow rating). Would I really need the 3.73s?

Are any of you with the new 2015 (or even the 2014) F150's 5.0L V8 Supercab towing the approximate weight and size trailer I would be towing with the 3.55s rather than the 3.73s. Have you and your tow vehicle experienced good towing with the 3.55s?
  • Why do you ask. If you will be ordering a truck or comparing available trucks with the 2 choices then take the one with the 3:73. If you have found a very good deal on a truck with 3:55 don't let it stop you. The load you are pulling will not greatly benefit from the difference. Again if it is about choices the 3:73 will be the best.
  • Terryallan wrote:
    Honestly. According to the engineers at the gear factory where I work. There is only 100 RPM difference between the 3.55, and 3.73 at 60 MPH, And 100 RPM will not be that big of a difference in power.


    It's a bit more than than 100RPM and even that seemingly little amount is significant when it comes to towing.
    I had TV that I've changed the gearing by less than 200 RPM and it was a substantial change in performance.
    Don't underestimate the difference in gearing.
  • You may as well get the most tow rating. With the 6-speed, you'll hardly notice the gas mileage difference, when not towing. When you are towing, in hills, or wind, you will appreciate the lower 3.73 gears.

    Jerry
  • RoyB's avatar
    RoyB
    Explorer II
    I would go with the 3:73 ratio..

    The 4:10 will give you best towing capacity and least MPH
    The 3:55 will give the least towing capacity and best MPH.
    The 3:73 is the best middle solution for towing capacity and gas mileage...

    Check the FORD F150 TOWING GUIDE PDF for your year of truck you are looking at.

    This is what I have done with the last three Ford F150s

    Roy Ken
  • F150's 5.0L V8 Supercab, with that combination along with towing a TT of any kind, I would go with the 3.73 gear ratio. The weight of the TT isn't as much of an issue as the wind resistance is.
  • Honestly. According to the engineers at the gear factory where I work. There is only 100 RPM difference between the 3.55, and 3.73 at 60 MPH, And 100 RPM will not be that big of a difference in power.

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