Hey guys,

It's time to buy new tires (again) and I'm finally going with a brand new set for my E250 Sportsmobile. I currently have really old Firestone Transforce in LT245/70/17 on 9" rims that can carry 3000lb each (true 80psi "LT" "E" tires). One of them just blew up on the freeway which was bound to happen given they're 10 years old and cracking badly.

I thought I had narrowed it down to Michelin LTX since they seem highly recommended, but it turns out Costco doesn't carry the size I want/need in "LT" spec. I had assumed all LTX models were "LT" spec but apparently not. They can be, but it depends on the size and 245/70/17 or 265/65/17 (what should fit) doesn't seem to be one of them.

There are 2 Michelin LTX models available:

Michelin LTX M/S2 (older model):
Size 245/70/17
Load index 110
Max load 2125lb @ 44psi

Michelin Defender LTX M/S (newer model that replaced the MS2):
Size 265/65/17
Load index 112
Max load 2649lb @ 44psi

They have 1 Michelin true LT tire in this size:
Michelin Agilis CrossClimate:
Size LT245/70/17
Load index 119
Max load 3000lb @ 80psi

My vehicle weight is ~7700lb with 3150lb front and 4550lb rear. So theoretically I would need ~2300lb for each rear tire, correct? Does this mean I could get away with the Michelin Defender LTX M/S in 265/65/17? I do not plan on towing. Thoughts? Suggestions?

EDIT: Playing around with different sizes, it looks like you can get the LTX's in "LT" for:

LT225/75/17
- Would be quite the stretch on a 9" rim as my current 245/70/17 are already kinda stretched.

LT245/75/17
- This might work and might be what I have to go with but will probably require a bit more trimming of my front plastic bumper bottom. I have had this size on these rims before but they weren't new and is why I had to trim the plastic a bit initially.

LT265/70/17
- Same problem as above, a bit too big.

 

IMO yes you need LT tires, you do need the load capacity but it's also about control and stability... P rated tires on a heavy truck tend to be very mushy feeling even if they have enough load capacity..

 

I have used Michelin LTX tires since early 2000's and have not regretted them one bit. Currently running my 2005 E-350 extended body with raised roof, weighs in just at 8,400# as a daily driver work van (Frt: 3380, Rr: 5080), chose Michelin Agilis BUT in the LTX configuration which differs from the CrossClimate version. For some reason the CrossClimate didn't appeal to me as I've been using the LTX Defender without a single problem or issue (Mine were bought from the Winnebago factory as brand new take-offs, got a fantastic price of $105 each, that supplier is long ago out of stock. )

In all honesty I'm concerned only with quality, ability to handle my loads and decent mileage--"comfort" is not a concern at all. Your Sportsmobile is a bit "light" all things considered so I don't think you're ill-advised considering Michelin's. I would cruise the Sportmobile forum to see what many of those owners run---its a great site for those types "adventure vans".

 

Yea absolutely. I think I was just confused as to why some LTX's came in "LT" spec and some did not. It turns out only some sizes are LT or E or "10-ply" (all mean the same thing lol).

 

"LT" and load range E are not equivalent. I wouldn't be surprised if all load range E tires are "LT", but all "LT" tires are definitely not load range E. I used to have an F-150 and ran LT235/75-15 tires on it which were load range C.

LT tires are a little stiffer, stronger and more stable than P tires of the same size.

Load range E is often called "10 ply", or more accurately "10 ply rated." But they usually don't have 10 plies. 3 to 5 is more likely. Back in the day tires did have the number of plies they said, but as tire technology improved they could make strong tires with fewer plies that worked better than the old tires. So the load ranges letters came in to refer to the strength of the tire like the ply count used to do, but didn't anymore.

 

I can tell you those 10 ply tires separate with age, so far every set I've ran as they age start to pull apart, I can't go below E, extended E350, it is heavy, wish I could make a dually and drop to some D load tires.

 

If you are looking at the weight rating for non LT tires, remember to deduct just under 10%. When determining the load capacity of a P series tire on a light truck, van, or commercial vehicle, you have to use 91% of the max load as the actual max load, as it isn't designed for vehicles with a higher center of gravity, or a potential to be more fully loaded. Also keep in mind when you load your vehicle, it won't be perfectly loaded from side. There is no guarantee that the 4550 on the rear axle is split 2,275 per side. So a P rated tire with a max load capacity of 2,000 pounds has a max load capacity of 1,820 when used in an LT application.

There are multiple articles discussing this, and I think the US DOT actually has a legal ruling for it.

https://www.worktruckonline.com/1565...or-trucks-suvs

 

^^^ In running P-rated tires in an LT situation I'd be concerned with heat built up when hauling heavier loads.

I would ask OP if he's viewed anything on this topic over at SportsMobileForums?

 

Yea I'm definitely going to go with LT tires now. Just trying to figure out if 265/70/17's will fit with my setup. I'm set on the Michelin Defender LTX and that's the only size available in LT (or 245/75/17). FYI Costco has the exact same tire (in addition to the defender) as Michelin "X-LT" but is a little bit cheaper. It's a "club" only tire but according to others on this forum is the exact same tire.