Shopping for tires - LT's or P's
 

I've got about 27K miles and had a flat last week, so I'm riding on the spare. My current tires are the 18" Pirellis which seem to be the second least puncture reistant tires, contenentils being #1.

My 4X4 EL is anything but a light weight vehicle, especially when I'm towing my 31' travel trailer (weighing in at 13,000 CGVW). The stock tires were "P" tires, or "Passenger car Tires", which from what I understand might be a bit underrated for this vehicle, not to mention they are more likely to puncture.

My question is, is it worthwhile to upgrade to a "LT" or light truck tire? I know the cost a bit more, the ride might be a bit rougher and noiser, but I'm really sick of flat tires! I don't off road much, but when I'm on dirt roads, I would like to have some puncture resistance from rocks, branches, etc..

I'd like to hear what other's opinions are and if there's an alternate size to the P255/70/R18's that came stock and are kind of an odd size.

LT tires are not an upgrade unless you think an uncomfortable ride is desireable.

The Rear GAWR of my "short" XLT is 4250 pounds and I'm guessing your EL is too. That's with the tires at 35 psi. The GAWR never gets better no matter what tires you put on there. My stock P265/70R17 tires have a maximum carrying capacity of 5070 pounds (2035 x 2) at 44 psi, much more weight than the axle weight. Plenty of tire under there. Even at 4938 pounds for your tires there's still more tire capacity than the axle rating.

I guestimate our GCVW is maybe 12,000 pounds and tire capacity isn't any concern. We have an Equalizer WDH to reduce the load of the 700 pound tongue weight on the rear axle.

Bump the rear tire pressure up to 40 psi to stiffen the sidewalls if you thing they're squirming.

Light truck tires don't seem to have as much capacity in the same size tire I have, even at 51 psi, and I can't find a LT tire in your size. For example the highest capacity 17" LT tire I can find only has 2271 pounds capacity. That's a degradation of almost 500 pounds and I'd have to run 51 psi to get it.

-- Chuck

LT tires are purposely rated lower than P tires to leave a margin of safety in truck applications. Likewise, if you use P rated tires on a truck, you need to REDUCE the max weight rating by 9%.

Tire Rack Article on P rated tires on trucks

That said, if you value ride at all, I would stick with the P rated tires. The LT's will be choppier riding, even at the same air pressure, due to the thicker sidewall.

If Michelin makes a tire for your application, I have found them to be excellent tires with an excellent ride quality. I have the LTX M/S Michelins on my van--they came OEM and I replaced them with the same.

Another decent new tire is the BFG Long Trail T/A Tour. These cost far less than the Michelins, get good ratings, and come in a 265/70x18, which is only a tiny bit larger than your stock tire, so that should work well.

George

I would not get LT tires. Way stiff and bouncy.

When it had Discount tire fix 2 leaks, they recommened it go to a different size of tire since the 255/70/R18 is hard to find. They recommened 275/65/R18 which is the same size (only 0.01" larger in diameter) and only 0.8" wider. Discount said that size are more commonly used as LT's on F250's & F350's trucks.

George suggested 265/70/R18 which are 0.55" larger in diameter and 0.4" wider, however when my speedomter says 70MPH, I'd be going about 71.2.
Anybody using any tire sizes other than stock? I'm not looking for something real wide or tall. I want to keep the ride comfortable, not screw up the speedomter too bad, and no clearance issues.

I would stick with the same size. There are plenty of choices in that size. Look at the Goodyear Fortera Silent Armor or Yokohama Geolander both good tires. The Scorpions are a cheaper tire IMO.

I don't have an Expy, but I would imagine that either the 265/70's or the 275/65's would work OK for you. There is usually a spare 1/4-1/2" clearance on all vehicles in all directions. Or, if you can find a tire in the stock size, that would be a no-brainer. The Goodyear Silent Armors seem to be good tires but are very pricey. The Yoko Geolander is available in a few types, I think, and not all of them are equally good.

1.2 mph difference at 70 is less than a 2% error, and is so close that I wouldn't worry about it. If you are concerned about ride, stay with the P rated tires.

Given these two alternative sizes, I'd probably go with the slightly taller tire to give a bit more protection when whacking chuckholes, but we're splitting hairs pretty closely here.

Good luck,
George

After I stopped kidding myself that I needed quasi "off road" tires on my SUVs I put a set of Bridgestone Dueler H/L Alenza tires on my '02 Explorer about 18 months ago before my daughter took it to college with her 330 miles away and across the Alleghenies. I knew she'd be driving home a few times during school breaks as well as driving in the Pennysvania countryside around Gettysburg College.

The excellent ratings of this tire and her experiences in local driving and coming home via the Pennsylvania Turnpike in all weather conditions have put this tire at the top of my list for the Expedition sometime this year as the truck nears 40,000 miles.

They ain't cheap, though! Even from Tire Rack.

(In the quasi off road the AT Duelers ran very nice albeit a bit noisy. Much better than the Michelien OEM tires.)

-- Chuck

I just bought a set of Michelin LTX AT2 yesterday and all I can say is wow. The Exped. now drives much firmer not in a harsh way but in my opinion the way it should ride. I went with the LT275/65/18E and they fill the wheel well nicely and are the same height just a little wider. I tow a 33' TT and cant wait to see if the difference is what I am hoping for. I will post some pix if I can get it to work.

Tim

07EXPYEL -

What a great post as I have also been recently looking in to replacement tires. I have the OEM Pirelli Scorpion STR A 255/70R18's. They still seem to have quite a bit of tread left after only 25k miles on them however I unfortunately picked up a nail a week ago. The nail wasn't in the tread but was on the side of very outer rib, right where it looks like the rib transitions over to the sidewall (see picture links below). A friend helped me plug it as you will see but it's not pretty and I'm not feeling real good about it being a good long term solution, especially since I do tow a Travel Trailer that weighs in anywhere from 7k to 7.5k. I stopped in to a shop to have it looked at where the nail was and they said it couldn't be patched.

I could pick up just one replacement Pirelli. But with the other 3 tires having 25k miles on them I'm questioning if that would even be an OK option as long as the new one was on the rear. I'm also wondering what opinions are about just replacing two tires for now and putting them on the back? Ideally I would like to replace all 4 but unfortunately $ is pretty tight right now.

Overall I think I have narrowed my choices down to going with the 275/65R18 size since there are many more options with it. And then to go with either the Yoko Geolandar A/T-S (C rated) or the General Grabber HTS (E rated).

https://www.ford-trucks.com/forums/a...pictureid=4395

https://www.ford-trucks.com/forums/a...pictureid=4394

One option for replacing a single tire on a 4WD/AWD vehicle and matching size is to find a tire store that will shave the new tire down to the same tread depth as your existing tires. Although it seems a bit of a waste, you are preserving a lot of miles on the existing three tires.

Racers and autocrossers frequently shave tires to reduce tread depth to make the tread stiffer and less liable to chunk. If you can find a shop that sells tires for competition as well as regular tires, you may be in luck.

Good luck,
George

I have been through the same situation with 31X10:50x15's on a bronco without TracLock.

If you dont have TL/LS etc, I dont think it will make much difference. Certainly wont be worth all the effort to try and figure out a resolution. I am not sure how much tread depth a new tire has (I also have an 07 EL w/18" pirelli's). Maybe ~14-15 32nds. So, if you have 25K on them, then maybe you have used ~5 32nds. If you do the math for circumference on a circle (tire diameter) I think the relatively small amount of wear in 32nds will not amount to any appreciable percentage of difference. For that matter, a worn out tire wont have a very large percentage of circumference that is lost.

I am thinking that you should just get a matching new tire, stick it on the front for a while and run with that. You (as I did) can drive yourself crazy trying to figure it all out-----and it may not be worth it.

Now thats just my .02, so its your decision :) LOL

I feel your pain. The continentals (17's) that came with my '04 Expy were shot at 29k. I replaced them with a set of Mich. LT's and have been nothing short of extremely happy. They are pricey but perhaps one of the more forgiving tires on the road. They have worn evenly at all four corners, no cupping or adverse wear at all.

My only complaint would be that I have 33k on them now and I'm starting to shop for tires again. I estimate that they will last another 8-10k.

The ride is a little stiffer but they have been quiet and smooth. I don't think I want to spend $220 per tire again so I'm exploring alternatives to the Mich.

Edit: I was just playing around on Tirerack.com and only the Dueller H/L Alenza in my size offers a treadlife warranty. The Mich. and the BFG Longtrail offer none. The Alenza also offers great ratings and a very fair price.

Tim

I didn't mention it in my first post, but I had already plugged two of my tires because I had nail punctures in the "Transition" area and the tire shop wouldn't patch it.
One of the tire plugs gave loose on the I10 after <100 miles, and thank goodness for the TPS (Tire Pressure monitoring System), because I was warned of the low tire pressure in plenty of time to safely pull off the interstate with trailer in tow. I knew I was taking a bit of a gamble with the tire plugs, but one tire had held fine for 2 months.
Money is pretty tight for me too (40% cuts at work), so I've been checking craigslist for tires. I ended up purchasing 4 almost brand new take-off's P255/70R18 Michelin LTX tires for $300 (It will work out to even less after I sell of the stock Tundra wheels with TPS sensors that came with the tires). This was almost 1/3 the cost of new Michelin's. These were off a 2009 Tundra, and have the exact same weight rating as the Pirelli's. Although I really would have liked the LTX AT2's, I just had to go with the best deal.
Since I still had two decent Pirelli's, I just put on the 2 new Michelin's on the rear until the Pirelli's wear out or get punctures.

rhc43 - You might want to check Craigslist for a single Pirelli to repalce your bad one.

ill chime in. I have had the continentals(Stock) POS, upgraded to P rated Nitto Terra Grapplers, good tire but didnt last long. About 3 months ago I upgraded and let me say upgraded again for BERRY, to LT 285/70/17 Hankook Dynapro ATM RF10's. Awesome tire, is quiet on the road, great tread pattern, almost puncture resistant, 3 ply sidewall, I think 8 or 10 ply tread. I am running them at 60 psi. max psi i think is 85. The expedition seems to drive so much better, less lean when turning, seems more sound to me. I will be sticking with lt's for my truck. The tires are stiffer but for me that is a good thing. Not as mooshy, plus there is way more tread on these tires when new. I was really surprised how deep the tread is, yet they are very stable, more stable than any other tire I have had on my expedition.

Discount tire direct had these for I think 151 a piece (about half price from the BF GOODRICHS), plus i got discount to match the online price and give me $25 back on the Nittos for wearing too quickly.