Gentlemen,

My 2000 Expedition comes stock with P265/70R17 tires. Passenger tires. The door sticker says stock spec is GVWR = 7000lbs with front P265/70R17 @ 30psi and rear P265/70R17 @35psi on 7.5" rims.

I'm buying new summer tires. Choosing between the Bridgestone Dueler Revos or the Michelin LTX A/T2. Both come in a P-version and an LT version in 265/70R17 size.

For both brands, the P-tire is rated at 2300-2500 lbs @ 44psi, the LT version is a load-range E with triple steel belts rated at 3100 lbs @ 80psi.

I use this truck for hauling equipment inside and towing a materials trailer. Also for towing the garbage trailer to the dump - which means trailering in the muck of the dump on wet days. Hence my interest in switching to an LT tire - just to be sure I'm not pushing the loimits of my tires when I'm towing the dump trailer with tools in the back of the truck down the highway.

But 80psi - I've got 60psi tires on my F250 and they're like rocks - real stiff ride. I wonder what 80psi tires are going to be like on the Expy. Call me a spoiled brat - I do like the comfortable, quality ride I've had on the stock tires.

Of course, I suppose with a 7000lb GVWR truck, I'd be running lower tire pressure - probably down to 70 psi.

But.....any thoughts?

 

If you value ride and handling, dont do it. LT are optimum only for heavy loads at lower speeds. P tires are most likely S speed rated while LT of the same brand and model are Q or R rated. Tread life warranties are also much longer on P tires and often you get no mileage warranty at all on LT's.

Jim

 

Just like jim said above, go with the p series tires. I just put tires on the wifes expedition and stock tires are p255-70-r16 s112 and there fine for the weight of the vehicle.

 

Now in my case, the last set of tires that I put on my 150 are LT265/75R16, load range C (6 ply) and they have a 60k mile warranty. My truck had the same size on it when I got it, but there were P's. They only lasted maybe 30k and they also were a 60k tire. The ride is a little stiffer with the LT and I run them with 45lbs in them, but there is less sideways roll going around curves.

 

Some wheels are marked for max. inflation as well, and 80 psi might be over your wheels rating.

 

The only time you'd want them at 80psi is when you have the max load on them, which you never would with an Expy. Other wise running them closer to 35psi isn't a problem. I had the same size tire in LT and switched to P's because of the cost and better ride.

 

Good point - I've seen that on other wheels. I can find no such marking on these wheels. I'll inquire, but I'm optimistic - they're new, good quality aluminim allow wheels.

 

Ya, that's the kind of thought process I was having too. Mostly I'm concerned about stressing the limits of P tires when I've got 1,000 lbs of equipment in the back and a 4,000 lb trailer behind.

Called Michelin directly - phone rep agreed that going to a LT tire for this kind of use would be recommended. Problem is, the only LT tire they make in Expy size (265/70R17) is the LTX A/T2, which they warned me is going to be noisier on the highway because of the A/T tread.

Such consternation!

So maybe I'll go ask in the Expy forum who has LT tires on their Expy and what are they.

 

yeah, what Galaxie said - 80 psi is the pressure you'd need to run if you're running the load limit for the tires. You can run them at a lower psi, no problem (but it should not be lower than the door sticker says)

The psi on the door sticker will give you the right "foot print" for the "normal" load that they expect - if you're running a heavier load, and sounds like you are, you should be running a higher psi than that...

 

If you have the 3800lb rear axle, you cant just increase your tire capacity and get away with it for too long. The P-metric tires in that size are already good for 2535lb @ 44psi each and the axle is only good for 1700lb per side. Even de-rating the P-metric tires 10 percent, which should be done for truck duty, they still carry 2281lb per tire.

Jim

 

At 2300lbs per tire with the P series that is 4,600lbs for the rear of the truck. You are going to bottom out the suspension in an Expedition before you overload the P series tires. The 9.75 axle has a GAWR of 4,500lbs. Stick with the P series tires IMO.

 

Ya, I agree totally with the last two guys - obviously putting heftier tires on isn't goig to increase the load bearing capacity of the truck. I'm just concerned that P-rated tires aren't "tough enough" for heavy-duty use. When I've got 1,000lbs of equipment in the back of the Expy, and a 3,500lb trailer of reno waste behind me, and I gotta drive over all the crap in the garbage dump to back up the hill to today's dump area - I'm thinkin' that having an LT tire under me is going to make me feel better.

Also, this comes from years past on the farm. We put P-tires on the F250's a couple times - ya, we grossly overloaded the trucks, welcome to farm life - but the P's were toast in no time compared to LT's.

I'm leaning toward C-ranges. Works out to about the same load bearing as a 113 service level P, but somehow I just have the feeling that an LT's construction is going to make it a tougher tire. Hmmm - a C-range with max inflation 65psi, run at ~45psi when the truck is empty, and at full inflation when hauling - sound like a good compromise?

 

I run LTs on my Blazer 4x4 & F250 4x4. With LTs you do get a little stiffer ride. On my F250 I run 50 PSI empty. That is what the tire dealer recommended. I run 35 PSI as per tire dealer. My F250 runs E rated 10 ply, 80 PSI MAX, my Blazer runs C rated 6 ply, 50 PSI MAX. The pressures you are giving are MAX PRESSURES. I would run the LTs because they are heavier built & will give you better tow handling with heavy trailers. The LTs are a little more costly also.