I have a 99 XLT supercab, with 5.4, K&N, dual Vortex exhaust, powerchip, and 33" tires, I haul a 28" Travel Trailer. I had alot of problems with it lagging for power at 60 - 70mph. Anyone ever haul with bigger tires, and if so, what mods do you recommend to haul with this combo? 5speed tranny maybe?

 

That's the only thing that's gonna help. A 28' TT is gonna weigh at least 6000 #'s all loaded up. With 33" tires and I'm assumning a stock 3.55 gear, you're at the limit. Get some 4.10 gears and you'll see an improvement.

The "stock" 5 speeds for the F150's have a lower towing capacity then the auto. Besides, you can't get a 5speed with the 5.4. I don't know what manual trans they run in the Super Duities with the 5.4, but it's "supposed" to be able to handle towing?

The 6 speed manual they put behind the v-10 and the Power Stroke are supposed to be pretty tough too.

 

Hi Un Welcome!

You have some good mods. Maybe someone here can give more input on the 33" tires..it does take more HP to turn them.

Whats the rear axle ratio? 4:10s would help. Of course for any substantial gains...gonna need a blower..magnacharger etc.

Also...on 28' TT....do you know what the weight dry/wet/loaded is?
If you weight both truck/TT...then...no guessing. GCWR/GVWR. If your grossly overloaded then youll know to reduce some wt. Naturally less wt. should help on towing speeds. Also safer & legal.

Geez...towing at 70mph...i sure dont recommend that...here where i live...UNLAWFUL is right.

Good luck and be careful. OT