Currently have a '09 F250 V-10, CC, 4x4, Lariot with 4.10 gears. Might want to go to Toyhauler that would weigh loaded close to 15klbs. Would swapping in 4.56 gears be a vast improvement for towing performance? What is the lowest you can go? We live in SW VA so have hills and mountains to tow in. Is this too much weight for a V-10. Length will be under 40'.

 

Do you have stock tires?

15000 is right around or just over your maximum recommended weight. Your truck can handle it, but be careful. When calculating, make sure you include all of your cargo.

Your truck was also offered with 4.30 gears, which added about 1000 pounds to the max recommended towing weight.

 

Going from 4.1 to 4.56 would be a 10.1% improvement in torque to the ground in a given gear.

And no, it's certainly not too much weight for your engine. That engine is offered in the F-650 with a GVWR of 30,000 lbs. That trailer may be a bit too much for your chassis however. Are you looking at a 5th wheel or conventional trailer?

 

I have the optional 20" wheels. How much does these reduce my tow and or payload vs the stock 18's? Tks.

 

Not sure how much the 20's reduce what you can tow but I think going to a 18" rim would be better.


4.30 gear I would think would be great.


You won't want to travel as fast (ground speed) with the lower gears but It should help it to stay in the power band.


Here are the towing guides:


Towing Guides | fleet.ford.com

 

Thanks for the towing guide. From this not worth the cost to swap in 4.30 gears from the 4.10's just to gain 1k in GCVR and best to stay at 12k lb or under for loaded camper.

 

without getting into a complicated chart of torque/hp values & bandwith comparisons, would the 4.30 improve mpg? or because the top end speed is slightly decreased, it would not?


Are the stock 4.10 gears the ideal for hauling/towing mpg? I am trying to determine what gears my v10 F250 has & if they are the reason my mileage appears to be lower than everyone else's (or if they are simply lying lol).

 

For comparisons sake, it did a gear swap in a vehicle previously & saw little to NO torque gain. Of course, it in no way compared towing or power-wise to the F250...1988 Toyota Landcruiser 12.5" suspension lift w/ stock A440f auto tranny & stock I6 4.0L...4.11 gears stock...swapped to 4.88s...identical mileage, performance, speed, etc. Didn't see the $1K spent lol constantly thought about WHY I didn't install the 5.29s but then wondered if they would have improved anything either.
Again, I do realize this is no real comparison "vehicle or even usability wise" (Cruiser towed little, offroad/trail use much).


thanks