The 2006+ F-150's with 20" tires are still rated for the truck's 7200GVW, plenty to pull a 7k+ pound trailer. It has nothing to do with the max air pressure, but the service description which defines the load rating (111,113,117, etc).

Every All Terrain tire is designed for trucks/SUV's (not that that Pirelli is an AT tire), not passenger cars.

Actually, I am recommending a P-rated tire with enough load rating to maximize performance, and sticking to stock size will yield best performance.

 

You're right. It has nothing to do with max air pressure. It does however have to do with sidewall strength and stability. The FACT is that an LT tire will be more stable when hauling/towing heavy loads than a P-rated tire.

Surely you're not trying to say that a P-rated tire would provide better stability while towing.

 

I've made my point. It has to do with load rating which includes this unmeasurable sidewall strength and stability you speak of. Except for the heavy duty payload package, we have at most 7200# GVWR and 4000# GAWR on the rear. Any P-rated tire with 2500 pounds of load is more than enough for our trucks. LT tires cost more up front and weigh more which affects suspension components, acceleration and braking by varying amounts all while offering a stiffer ride.

I have towed more than my tow rating, but the trailer I tow most frequently is about 2500 pounds loaded.

 

I can tell you two things based on my experience. First, an LT tire tows better than a P rated tire, like stated above I believe it can be directly attributed to the side wall - an LT tire has a much stiffer side wall. My 2003 regular cab FX4 (5.4) tows heavy loads MUCH better than my '07 Expedition. The Expedition will run circles around the F-150 power wise (3V 5.4 with 6 speed automatic and 3.73 gears) but when it comes to actually handling the load the F-150 is a lot more stable. I am die hard Ford, but why they put a damn Continental "P" tire on a vehicle that will tow 9,200 lbs. is beyond me - wait I do know - most people only them to haul the kids and dogs around in and not actully use. I will take stability over power any day of the week. Second, when I switched over to a 285/70/17 tire I liked it better for towing. I never was able to use OD while towing anyway and the added tire size allows me to more comfortably cruise along in third now. This is towing around 7,000 to 7,800 lbs.

 

Great advice everyone. I was on Ford's website and found this information on the 2009 heavy duty F150 package. It might not be the same as my 2005, but at least I was able to find something from Ford.

F-150 Heavy Duty Payload Package (Option Code 627)
• LT245/75R17E BSW A/T tires

 

I too had looked at the heavy duty package trucks when I was buying, and found more than one I liked. However, none of them had a LS diff. Don't know if they just came that way or you could not get LS with the heavy duty package. Even with 4x4, I want LS, or a locker like I got on the FX4. Fortunately, it also came with a size and type of tire I like LT275/70R17 LR C. tires.

 

LT E load rated tires are required for the heavy duty payload package as the GVWR and GAWRs exceed any p-rated load in that tire size. If one does not have that package (you don't), no worry.

 

Seriously, you have no clue what you're talking about. Load range E tires are not required for the heavy duty payload package. The GAWR is only 4800lbs and a load range D tire would be plenty for that load.

 

Technically, LT D are enough, yet there are no tires on the market that are LT D in that tire size. Practically, LT E are required. My point that you seem to keep missing is that p-rated tires are enough for most F-150s and the HD package is one rare exception, which the OP does not have.

 

I think the point YOU are missing is LT's will give you a much better towing experience. Ford isn't going to put P's on a truck if they aren't rated high enough for the rated loads, but they sure are going to save money and do it if the numbers are good.

 

And Ford puts the p-rated 20" tires i linked above on trucks that have a GVWR of 7200 pounds and can supposedly tow 10k+ pounds.

Part of the towing experience is stability while another part is performance. Tradeoffs. I think all the points are made; let the buyer understand them.

 

I suggest the best of both worlds. Get some extra wheels and mount smaller diameter LT's for towing, put the nice wheels and soft tires back on when you get back home. By the way, my F-250 LD came from the factory with P255-70-16's, some came with LT245-75-16E. I have an extra set of wheels with LR E's and have towed with both types on the same truck. Yes, the LT's are more stable, and no I'm not afraid to tow with the P's especially on shorter trips. Would I tow I-40 from Amarillo to Albuquerque with the trucks and strong winds on the P's? NO, have I? yes. Actually, a Hensley or PullRite hitch would be the best solution (for sway control) but $3,000 is too rich for me.