Howdy folks, new F-250 and looking for new, and larger tires. I'm going to eventually source a set of extra wheels for it as well, and would like to go with 22" rather than the stock 20's.

These tires: https://www.tirerack.com/tires/tires...es#testResults
Pirelli Scorpion ATR, and the size will be 325/55/22. This is a 36" tire basically, which compares to the 34" tire already on it. There appears to be enough clearance for the extra inch all around, however there are also wider, not just taller, so hoping they will fit.

I don't want or need a M/T tire, just not how I use the truck. It's my daily driver, and will be pulling a boat and trailer set-up that would be just over 10,000 pounds (boat is 7300 pounds dry). Off-roading isn't on my list of driving habits, not really. This is the only tire in this size, and it seems to be a good road-going tire. I've had them on a Navigator in the past, did very well. These are P-Rated, not LT rated. So the load rating is 116, versus the 123 that is on the truck. My truck is the 9900 pound GVWR option, so as light as these trucks can actually be configured. The tire in question has a load rating of 2760 pounds, which would equate to 11,040 pounds for the four of them, well above the 9900 pound GVWR of my truck. This would allow for some differential loading, meaning the rear could be loaded more than the front, leaving room for the payload of this truck, which is just under 2000 pounds.

Also, if I run a forged wheel (and not too wide, like 9" wide), the entire set-up should be no heavier, and maybe lighter, than the stock set-up, meaning handling and fuel economy would not be negatively impacted. This seems like a good thing.

The question is, could this be acceptable to use in this application? The load rating seems to be there. They run less pressure for that load rating, which could help the ride I suppose a little, is this any kind of problem?

For those with any experience with all this, please do help me with your experiences and thoughts!

Many thanks in advance,

AidenFC

 

I think you are going down the right road looking at the actual load rating, and not just the P, C, D, E rating. Have you ever weighed your axles with the boat hooked up?

I think you'd get faster tire wear with the lighter duty tire, but maybe that's an acceptable trade-off.

 

I would not do it. Get a proper LT tire. Truck weights more than you think.

 

I would make sure that the tires can support the max rear axle weight (sticker inside the driver door shows it) or at least weight that you are hauling based on a scale weighing. The number one reason tires fail and explode is because they are overloaded or under inflated for their loading. You dont want that when towing.

I would also say that when hauling with P tires things will feel a bit more squishy because the sidewalls are not as firm. This also gives you a softer ride as a result. I went from P to LT on my F150. Ride was slightly worse but tow was slightly better.

If you are comfortable with the weights and ride no reason I could see to not go do it.

 

Me thinks I smell another drivability/death wobble/ handling problem thread coming up directly. But, what do I know.

 

Thanks, the tire wear would be a thing to watch. I haven't been able to hook this up and weigh it yet; own the boat, but don't have it here yet. That'll happen in spring. Trying to get the wheel/tire combo done before I take the winters off the truck...

 

Thanks DbleDan, good point on the axle weight rating. OK, the front GAWR is 5200 pounds. The Rear GAWR is 6340 pounds. That's 11,540, and the GVWR for the truck is 9900 pounds.

How does this work?

Not sure how that all adds up, but the Rear GAWR is too high for these tires now. Crazyness.

 

Be careful with P tires on SUVs and light trucks, as their load rating must be reduced by ~9%. Here’s the industry standard guidance, in this case from Toyo:


P-Metric or hard metric tires on Light Trucks

When a P-metric or metric tire is installed on a light truck (SUV, pickup, minivan), the load capacity of the tire is reduced by a factor of 1.101 as prescribed by the Federal Motor Vehicle Safety Standards (FMVSS). For example, 305/50R20 has a maximum load capacity of 3086 lbs. If this tire is fitted to a light truck, then the actual allowable load capacity for the tire is 2805 lbs. (3086 lbs. divided by 1.1). If you replace the original tires with the exact same type (P-metric, hard metric, LT-metric, or flotation), size designations, and ply as the tires that were originally installed, just follow the vehicle’s tire information placard for proper inflation pressures. If, however, you apply a ‘Plus zero’ or plus-1, etc., fitment to a light truck, you must discount the replacement tire’s load by the 1.10 factor and ensure that the replacement tire has sufficient load capacity by inflation to support the load of the originally installed tires.


HTH,
Jim / crewzer

 

Your door cert is simply a paper derating for registration purposes. The axles and all that connects to it is still a fully capable Super Duty and a sticker higher than yours.

Don't skimp on the tires.

 

I think it's common for the two axle ratings to exceed the vehicle rating.

 

Hey guys, thanks again for the info. With the 10% derating, I simply would never known, thanks Jim!

So this 9900 rating is a 'paper de-rate', and the truck is actually capable of more... I think that from a liability or insurance or regulatory perspective, being over the 9900 pounds total, or the 1966 pounds payload, including passengers and cargo, do you think this is correct? Which really means I couldn't legally overload these tires anyway, even if the axle ratings are higher.

Thoughts on that?

In reality, this boat tow is the biggest load it'll likely ever see anyway...

Or am I just trying to cherry pick one data point to make it fit the outcome I want!!??

Thx again!

 

The derate them in variously locations such as ca, Ny, NJ so that those folks can avoid various registration, commercial insurance or other problems. Keep the tires, enjoy the truck, and pull the boat with your family and call I a day.

 

Many tire places will not let you put lighter load capacities than what it is stickered for but some will not check. Your tire load rating should meet or exceed 6340 when 2 tires have been added up. Basically the load rating should be 3170 lbs per tire to support the rear axle rating of 6340. This is higher than the gross weight of 2475 because you can put more weight on the rear than 1/2 the total. Ideally you would have some room beyond 3170lbs because loads are never really that balanced and you may overload one side vs the other.

The reason I suggest weighing it is to make sure you would not be over the max tire weights.

Others are right that trucks are de-rated on paper for tax and registration reasons.

 

Cool info, appreciated. I guess the 22" plan will have to be modified. There are limitations on what tires are available for these; if we want aggressive off-road tires, no problem, but for highway folks not so much.

I'll keep researching, ideas welcomed,

thx all,

AidenFC

 

I run cooper tires on my trucks. Great tires.