Load range D vs. Load range E tires
 

It's just about time to replace the tires on the X. I have been considering going to an E rated tire vs the D rated ones I have now. I am a summertime tower with a 32' travel trailer. I thought the E rated tires might be a little more stable when towing. My hesitation is whether the E rated tires will effect the ride quality. The D rated tires I have now do the job just fine, but I thought since it is time to buy anyway, if there is not much difference in ride quality, I might as well get the heavier duty tires.
Any thoughts or suggestions?

The E's will have stiffer sidewalls and make the rear end a little less squirmy, but if your X tows fine with D's, why not stick with them?

and you can actually find D's with more load carrying capacity than some E's....

now speed rating is another chapter in the book :)

If you have the original tires, and they're D-rated Firestones, go to your dealer to check on your recall notice. Ford/Firestone will replace all 5 for free, and provide E-rated replacement tires. There's nothing wrong with the original D-rated Firestone tires, except they're just "not enough" tire for the heavy X. Ford tried to skimp on some cost and went with the D's, when the X really needed E's. I kept my D-rated tires at 60PSI at all 4 corners, and they've been fine, with excellent treadwear (72K miles or so & only 3/4 worn). I'm waiting for my local Firestone dealer to come up with the BFG replacements. Meanwhile, I've also gotten some E-rated Nittos on some new rims. I'll probably sell the new replacements after they're received.

Be careful, not ALL the Firestone Steeltex D rated were recalled. I have the "R4S" version, Ford/Firestone will not replace them even though they are still only D rated with some cracking on the sidewall near the wheel.

I put E's on mine at about 38,000 miles, along with heavy duty valve stems. We tow a 31 ft trailer and had a D fail while towing. The valve stem, which I believe was replaced with a marginal light duty rubber unit good for 65 PSI, was what failed, taking the tire with it.

I've seen used Ex's on E Bay and elsewhere that have had C's installed. :rolleyes: :rolleyes: :rolleyes: Future pre-owned buyers beware!

If you run 265/75-16 load range E at 55-60psi, you won't notice a difference in ride or handling. E's can be pumped up to 80psi when towing & that makes one heck of a difference. 285/75-16 & bigger sizes have a higher weight capacity in a "D" designated tire. Size does matter!

The ONLY reason I'd run 265/75-16 D's is if I had a gasser motor & or never pulled a trailer. Then D's would be fine.

If you had a 5.4l gasser & never pulled a trailer, C's may possibly be OK. I'd check tire load capacity or just run "D's" and be certain. Anybody know the GVWR w/ a 5.4

But you will notice the difference when towing.

My D's have a capacity of 3000 + lbs. each versus 3400 lbs. for an E (265/75/16).

3000 lbs. x 4 = 12,000 load capacity. Not much of a concern to me as my X will never go over above about 9500 lbs. fully loaded. (GVWR is only 9200 lbs.).

Yea, I know, it's not evenly distributed front to rear with a trailer, but that is why I have a WD hitch. The hitch throws a lot of the trailer weight to the front tires.

I pulled 7000 lbs to KC a few weeks ago. The rear tires were only a 5-10 degrees warmer than the front tires (checked with a infrared thermometer).

Jshira, Before I added Hellwig sway bar, The only thing that would improve handling while pulling 29' enclosed trailer was airing tires to 80psi. The D's that were on there stock "aired to the max" were uncomfortable to tow with. E's at 60 psi towed the same as D's at 60psi. For me the E's (80psi) helped a bunch & I wasn't anywhere near loaded capacity. I'll be adding Radius Rods in the near future & I'll report my findings there too.

If someone has D's & never needed more, buy D's. Personally, I NEVER see myself going back to D's. Unloaded my E's are at 55psi & I have the ability to go to 80psi when ever needed. I like options.

Thanks for your input,

Dennis

Yes, that makes sense. E's have an extra 2 plys in the sidewalls, which makes the sidewalls stiffer. I'm sure the E's are less squirmy.

The tires that I wanted only came in D's. I would have gotten E's otherwise.

You are probably right that D range tires ride better. I have the Firestone D range and have been pleased with the results as far as wear . They are a bit bumpier in town, but great on the road especially with a load.I have about 30000 on mine presently.
Ken Robinson

i switch to michielin ltx m/s e rating and it the ride was incrediable verses the firestone e rating i though i die and went to heaven

I have load range E tires and love them compared to the D range.
Much more stable.

You are obviously very happy; do you pull with your truck?

Tell me more, is the tire quiet on the open road, OK for most weather????
Does it collect rocks and then pitch them at the fender and innocent folks behind you???
Inquiring minds want to know :p