Tires for towing XL vs E load range.

[JetDriver]

Its new tire time and I'm debating between XL load range tires and an E load range LT tire for my 2017 Expedition EL. I'm towing a 32' 8000 lb trailer and dealing with the rear end wiggle common to the IRS Expeditions. I've heard from some others that E load range LT tires have been a significant improvement so I'm looking for input from people who have made this move to either an XL load range tire or an E load range tire on their Expeditions.

Thanks

 

[Meeker]

I'm towing a 7200lb 26' trailer, and I made the switch from the Primacys to Michelin AT/2 LT tires. There's pros and cons to the switch:

Pros:
- pump up the tires to 50-55 psi when towing and the sway/wiggle is greatly reduced.
- much better performance in winter
- almost impossible to get a flat tire from nails etc.

Cons:
- I think just pumping the Primacy tires up by 10 psi would have improved the towing experience as well. No idea how much improvement because I didn't try it.
- Mileage dropped about 1 L/100km (~7% ?)
- Rougher ride - I drop mine down to 40psi unless I'm loaded with anything (technically they should be at 44psi to carry the GVWR of the truck), and they're close but not quite the same as the Primacy tires for ride.

My 2 cents.

 

[GlennSullivan]

I just asked the same question in another post, thanks for the info. Are you down +/- 7% fuel economy across the board or only when loaded / towing.

 

[JasonH]

I just asked the same question in another post, thanks for the info. Are you down +/- 7% fuel economy across the board or only when loaded / towing.

For local driving, I average between 15 and 16 mpg on premium with my "E" tires. I don't recall what the average was before upgrading. I honestly don't pay too much attention to it anymore. My other car gets over 100 mpg (it's electric), so we don't drive the Expedition unless we need the space.

My "C" tires at 50 psi weren't as good at towing as the "E" tires. I disliked the "C" tires, even for daily driving. They made the handling very mushy and the vehicle felt completely unstable going over 75 (passing on two-lane roads). It could have been specific to that brand, but I wanted "E" for more stability and for increased puncture resistance, especially while towing.

 

[Meeker]

I just asked the same question in another post, thanks for the info. Are you down +/- 7% fuel economy across the board or only when loaded / towing.

I assume across the board, but honestly I can only state that based on non-towing. With the Primacy tires I could get 9.1 L/100km (25.8 mpg) on a trip from Calgary to Field BC (i.e. in the mountains) and back with no wind. I can't seem to get better than 10 L/100km (23.5 mpg) on these tires.
When I'm towing, there are too many other variables - any wind has such a drastic effect on my mileage (tall travel trailer) that I can't tell if the tires make any difference.

 

[chuck s]

Meeeker has summarized this very well. Since I only tow infrequently (a few times every Summer) I'm running the OEM tires -- and have been the past 20 years towing campers. If I remember I boost the cold tire pressure to 40psi. Frequent temperature check shows nothing abnormal.

Keep in mind the RAWR does not change fitting LT tires so you don't any extra weight carrying capacity. No free lunch -- still limited to roughly 920 pounds on the ball with a WDH.

-- Chuck

 

[Frank Swygert]

I have an older 2005 model, bu has the IRS. I tow an 8k trailer, but infrequently. I add another 5 psi to tires ( Uniroyal LT type) when towing. That does help some, but replacing the puny little 1/2" rear sway bar with a 1.25" helped the most. I have a set of Sumo spring inserts, but haven't installed them yet.

 

[Towinexpy]

Hey Jet Driver,
Going through the same struggle with my 2017. My concerns are from an everyday driver occasional tower say 10x a year. I tow a trailer that runs about 7500#'s depending on the length of our trip. Agree with everything mentioned here so far. Really thought I was going to move to an E but after some soul searching and spec comparing I am leaning towards the XL. I think you have to look at is how often do you tow? If it is a lot than the E may be the way to go. If its occasionally and the EXPY is the daily driver those E rated tires put a lot of unloaded weight at each corner. Look at the specs of your OEM tire and what you are considering. In my case it was adding 15 lbs. at each corner for an E rated tire. I have OEM 20's and even went as far to look up the OEM weight of the 22's and the 22's are only a pound more than my 20's. So I could not rationalize the extra weight even if I had the 22's. Since it is mostly a daily driver not sure I want to suffer a gas mileage and handling loss. (FYI I am more about the Boost than the Eco but there is a limit.) Also be advised while your TPMS sensors will work they are rated for your OEM tire pressures not the pressures an E tire can run at. So a low tire warning on your OEM tire may be really low on an E tire that you are running more air in. For what it's worth I am leaning towards the Cooper Discoverer AT3 4S. It is an XL tire but where as my stock tire has a load rating category of 113 this tire is a 117 (still an XL tire) buying a little extra insurance about 300#'s worth over the stock tire. And yes do not exceed your axle rating. As mentioned above I am also looking to upgrade the sway bars and possibly add the Sumo inserts.

Good Luck!

 

[JetDriver]

Thanks Everyone for your input.

I ultimately elected to Install Continental Terrain Contact H/T in size LT265/60R20. I'm running them at 48 psi which is what Contiunental Recommended for my vehicle. So far while there is a minor increase in ride harshness its nothing objectionable. I've not yet had a chance to tow with the LT tires. My next and last upgrade will be Bilstein 5100s installed at stock ride height. I've also installed Sumo Springs on the rear (it took my mechanic two guys with a crow bar to get them in after I gave up trying to do it solo) and the Hellwig HD rear sway bar which was a very easy DIY install. The Sumo Springs made a minor Improvement and the Hellwig was by far the biggest difference of those I've towed with so far.

To a couple of points raised here. Yes I know the RAWR etc doesn't change as a result of any of these changes. I did try previously going to max sidewall pressure on the OEM tires when towing and while it did help the rear end wiggle some it certainly wasn't cured. I strongly suspect the real issue is a poor design of the IRS WRT to carrying heavy loads. The rear end of the truck wiggles around when towing and this is true both with the trailer loaded up for camping and the family in the Expy and empty with just me in the truck. To really cure it likely would require replacing all the bushings in the rear suspension with stiffer ones but that's and expense that I'm not going to go to. It's a shame that Ford doesn't offer a HD tow package with the Expy that's actually set up for towing mid size travel trailers.

 

[JasonH]

Let us know what you think after towing. I noticed an immediate and substantive improvement. I was worried about the ride quality as well, but at 45 psi it's not that much worse and handling actually improved. The rear feels much more planted towing at 65 psi. As a bonus, it handles better and I have increased puncture resistance. I haven't felt the need to upgrade anything else after going to the "E" tires.