Hey guys,
I tow with my 2006 SC F150 4x4 that has 5.4L, Auto Trans, 3.55 gear ratio, a 6" lift, 17" wheel with 35x12.5x17 m/t's. Mods I have done include a Pro comp tuner, " cat back and a AFE intake.

Looking for some more towing power without re gearing. How much more power should I expect going down to 33x12.5x17 tires?

Thank you for helping out :-)

 

I would say stepping down to a 33 is your best option for more power. Other than that man, would be a supercharger. You can pretty much count on your tranny blowing out though. You could try a tuner with custom tunes but I think your best option is stepping down to 33's.

 

33's and a custom tow tune, if your dead set against regearing. What are you towing?

 

Do gears and be done with it. Tire size will help out some, but you can keep the look and gain the power back with gears.

 

6" lift and 33's is going to look terrible.

Re-gearing is your best option even though you don't want to.

 

why lift the truck and install big tires if you can't afford the re-gear??

 

Thank you all who helped! As for tarajerame, truck runs perfect when not towing. Who said anything about not being able to afford re-gearing?

 

People just assumed that since you were set against it. Bottom line is putting on a set of Yukon 4.30 gears to turn those heavy 35s would be by and far the best option. People think steeper gears will hurt mpg, but in cases like yours it actually improves fuel economy since the engine doesn't have to work nearly as hard - even when unloaded. Also it would get your speedometer back closer to correct.

 

No 4.30 for the front diff.

if you are towing, you want 4.56 with 35's.

 

Re-gear the truck, it's going to cost you just as much to buy new tires as it will to re-gear the truck plus you get to keep the look that you worked hard to achieve in the first place.

 

+1

 

Supercharging done correctly will not blow the transmission. The are plenty of threads on this site that actually discuss how robust our transmissions are. The weak point is actually the engine internals, which fail under intense boost pressures. I too am in search of more towing power and plan on installing a Whipple and running it at the default of 8psi with a professional/reputable tune. If installed and operated properly there should be minimal degradation to engine/drivetrain life.