FORD F-150 AXLE RATIO CHOICE
My new trailer (Keystone 26RBS) weighs only 6600 lbs + cargo. I’m about to order a 2021 Ford F-150 equipped as follows: V6 3.5 engine Standard (not Max) Trailer Towing Package. This truck has a 10...
Forum Discussion
dodge guy wrote:valhalla360 wrote:JRscooby wrote:
Everybody is talking about no difference at highway speeds. But the high speed gears will put more strain everything when starting the load.
Assuming you don't exceed the ratings...it will only put more strain on the drive shaft and rear transaxle gears but they are rated for that extra load.
Everything else will see identical strain levels.
- The axles past the pumpkin have no clue what is providing the torque.
- The transmission will simply select a different gear to keep the strain the same and the engine won't know the difference as the overall gear ratio will be pretty much the same.
It's only if you exceed the max rating for the rear end that it becomes an issue.
With a lower gear (numerically higher) each gets in the transmission will then become that much more efficient. So if you were running in 5th or 6th with 3.30 gears you could run in 6th or 7th (all dependent on transmission gearing) with 3.55’s. Also with the lower gears the truck will accelerate easier and maintain speed easier due to the increased efficiency. The only place you “might” see a loss in mileage is unloaded highway. And that number may only be .2 at most!
Sure, the transmission being up a gear is more efficient...thru the transmission.
But that's largely canceled out by the rear diff being less efficient.
Net effect is the rear diff doesn't make much of a difference with the new transmissions unless you exceed the max rating of the low (numerical) rear end.
