Unlike almost everyone else around here, I'm hauling weight all the time.
It's an '05 XLT, 2WD, 4.2, 8-foot bed... steel ladder racks and toolboxes mean I carry at least 1000 pounds at all times, and it's all loaded directly over the rear tires. (gotta say that i really appreciate the stiffness of the '05 frame over the '89 I used to drive)
Now it's time for new tires. I was thinking it might be a good idea to use tires rated for higher pressure to compensate for the weight.

The General Grabber-HT's I'm currently using are rated at max 42 pounds. Perhaps I would get something rated for 65 pounds pressure on the rear, and use "normal" pressure tires on the front. Would this be recommended? Or should I use the same pressure for all four?

I could not care less about factors like noise and ride smoothness, and with the extra weight, I get great traction in all conditions. So milage is my primary concern. Will I get better milage with the higher pressure tires? I'd bet that i do.

Now when I'm shopping, all the tires I've seen so far with 65 pound pressure rating are called all-terrain or off-road. Do All-season tires with 65-pound pressure exist, or am I missing it? Pressure rating does not seem to be listed for most tires.


P.S. I keep my snow tires on separate rims and switch them the day before first real snow is forecast.

 

hi what size tires? 17inch? there should be load range E tires which are rated at 80psi

 

ugh. 245-70 on stock rims.
As many times I thought of that number today, forgot to put it in the post.

So the load range basically means the number of ply's right? Like load range E would be 10 ply, D is 8 ply... etc.

 

hi basically yes e is 10 d is 8 c is 6, i personally got 18inch toyo mt's which are e rated 10 ply cause thats how they come for the size i got, and i would rather have a heavier duty tire then one thats at its limit all day, If i was you i would get a e rated should big some selection in 17's as chev 2500's come with 17inch. Michelin has the ms tire i believe which is more a street tread then all terrain.

 

FWIW radial tires don't really have plys, and load range isn't an exact specification either. Gotta look at two numbers max pressure and load rating in pounds. And yes I think in your use you should get a higher rated tire and might be able to find an appropriate size with a max pressure as high as 80, maybe not in 245 though.

I'd really be surprised if the tire your after isn't on the market, just hard to find, I have yet to find a good website for the details you need that covers many brands. Might just have to go to a few tire shops.

As for different front to rear, I'd recommend against it, no good reason to and prevents front to rear rotations.

 

I ran General Grabber HT LT tires on my 2004 Expedition and loved them. The higher pressure and stiffer sidewalls were just amazing for the fact the truck was loaded all the time. While the P rated tires are technically capable, I find the side walls flop all the time when heavily loaded.

 

I have an 08 reg cab 2wd with the heavy duty payload package. Ford specs say I can put 3000 lbs in the box. Stock tires are General Grabber LT245-70-R17. Ford recommends 50 psi in the front and 60 psi in the rear. Hope this is helpful for you.

 

18 wheelin, that's with the payload package that I don't have. I think that means an extra lug on the wheel?
HeyMrDJ, sidewalls flop... I am very familiar with this phenomenon.
JSWrules, I like your recommendation.
BruteFord, I found that tire rack dot com has detailed specs for all it's wares.
Thanks for good advice.

P-rated tires will generally get you something with a 2200 lb max weight capability, and under 45 PSI.
LT-rated tires get at least 3000 lb max weight, and generally have 80 PSI, but I saw a couple at 65 PSI.

I'm looking hard at the Michelins, They have four variations of LTX-M/S2 tires available to fit stock LT245/70R17 rims. Highway or All-terrain with two weight classes each. These are the top rated tires in "a leading consumer publication". One of only three LT tires with tread life rated as excellent.
It is important to note that Michelin's "LTX" is a brand name and not the LT weight class, as you can get an LTX tire that is only P load rated. A little confusing.

The General Grabber HT's are rated pretty good too, and are $70 less, per tire, but less tread life too.

I've got six weeks until state inspection is due. Will continue the search.

 

Hmmm. Just when I think i've got it all figured out...
Tire rack.com says 80 PSI max, and when i go to the Michelin website, the exact same tire is recommended for 50psi front, 60psi rear.
Now I'm confused again. I guess I'm just supposed to fill em until the sidewalls look good? WTF!

EDIT: Ah, the michelin website is buggy, a least on my browser.

 

Actually the heavy duty payload package is more than just an extra lug. I am aware that you don't have it but I mention it because you are hauling heavier weights on a constant basis which is what the heavy duty package is for. The tires which come stock on that package should be about what you are looking for.

 

18wheeling definitely has a point. I'm not carrying enough weight for the 80PSI tires. What I really need is the ford payload package. 50psi front, 60psi rear. (and better brakes, etc)
I'm kinda stuck in the middle.

 

18wheelin, you have the 7700 package in a 08, WOW, that's a rare bird. I was working at a Ford dealership in 08 until the crash, I remember seeing the option still on the books but few others knew about it, and I certainly didn't think many if any were ordered.

delusional, I should have mentioned the tire rack site, for this kind of thing it's one off the better sites. What I don't like about most sites is that they lock you in on either a size search or a brand/model search. For example, you specify a 245/70R17 well what if a 255/70R17 get's you what you want for less, you'll never find it. A recent personal example, I just got tires for the car, it specified stock IIRC a 255/55/16, but I found that if I went to a 255/60/16 I could get a lot more tire for a lot less money. For you however, width has a lot to do with payload, and 10mm more for example isn't going to be a problem.

As, for tire pressures in the contexts mentioned, the 50/60 is Fords number based on the axle ratings of the truck, 80 is based solely on the rating of the tire. For example if the tire is capable of 3200lbs @ 80PSI, then 2 per axle is 6400lbs. But if the axle rating of the truck is only 5000lbs, then at no point can you really practically use all 6400 that the tires can handle and Ford thus would give rating less then the 80PSI max that the tire can handle.

Bottom line, first is your truck stock? If so, then look at the RAWR(rear axle weight rating) divide by 2 and that is the minimum rating you need for your tires. That said, more is a good thing, to a point, it makes for a more stable longer lasting tire.

 

Trying to not find that point. Is 80 PSI too much? Will I be fishtailing in the rain? Try to make a turn in an inch of snow and continue in a straight line? I don't think it's a good idea to jump from P to the E weight rating, I should go with D.


Here's something interesting. According to this site....
2005 Ford F-150 XLT Tire Size
the original tires on my vehicle were either P235 or P255, not the P245 I currently use. Only the payload package was standard with LT245 width tires.

Great, now I'm not stuck on the 245 and my options expand greatly, but in which direction should I go? Wider, narrower, or neither? The rim width is 7.5 inch or 190.5mm.
{edit} BruteFord already answered that question, Wider. But i'm still wondering, If the payload package had the 245 tires, why am I having such a problem finding them? Probably because I'm a newb. At least I'm learning a lot.

 

The point of that statement is that the ability to run a higher pressure and thus carry more weight on the same size tire is a good thing. That is until it gives you a tire that is too stiff to conform to the ground when the truck is empty and the tires at low pressure, semi tires for example would be too much.

That you can run the tires at 80 PSI doesn't mean you should, it means you have that option, you'd likely find a 45-60ish pressure works best. But from what I gather of your needs and desires the ability to run the higher pressure and the higher MPG of doing so is important to you. Thus IMO a 65-80PSI max pressure "E" rated tire is what will best suit your stated needs.


That's great, I'm by far no expert on what tire sizes fit well on what rim. I'll say in general a taller and/or wider tire will carry more weight for a given pressure, and a narrower and/or taller(to a point) tire will give better MPG.

 

Hi most likely it well be easier to find a load range e in a heavier tire as thats what all 3/4-1 tons run, and sometimes cheaper cause like said above more options. I would look at the lt 265 size as thats a pretty common size.