2002 E450 Superduty tires

I looked at the 235/85 tires before and they were slightly wider and there were reports of them touching each other under load.
The C rated tires in a Dual setup are going to give me about 2000lbs of safety margin when I'm running at max load. Being that my Class C is 31ft long the rear axle is at max load just about all the time when we have stuff in the motorhome, I do load carefully but it is just the way this is designed.
I did look at the rickson 17.5 tires and rims but then I'm looking at a $3000+ tire change with the rims and tires. The C rated Continentals are $210/tire from tirerack.com.
I'm going to see if I can find the Michelin Agilis Alpin tires and go with them. I always carry a spare and if I get stuck on the road needing a tire I will just pick up a normal E rated tire and put it up front keeping the duallys matched.

I don't "Look for Trouble" but I try hard to reduce Trouble's Impact. For that reason, I like things I'm most likely to be able to fix when we're somewhere off the the beaten path. So for our Class C that runs at max (and CAT Scale says it does...), I went to a commercial duty tire, from a popular brand, IN MY SIZE.
For example, Michelin's fabled LTX series is a great tire but it's still an OEM tire. Not a thing wrong with it, it'll do its job, do it well, because it's from a quality manufacturer. That said, Michelin's Defender and XPS are higher in their food chain, so I'd consider them as Performance and Durability Upgrades.
Our coach came to us with Bridgestone Duravis R250's. These are a Highway Tread, equivalent to XPS Rib. Because they had run smooth and quiet, and worn well, I bought another set. So far no problems.
It's clear to me that the "C" in the Euro tires is roughly equivalent to the "E" or the "LT" in our USA designations. Yet I cringe, already hearing "My tires were C so I replaced them with D. That's better, right?"
Only Promaster I've been close to was a Canadian stuck in sand by my campsite last fall. Pulled it out by the hitch so we wouldn't tear up all the plastic. Only Promaster I've read about was an RV that turned out to have near-zero carrying capacity because of its single rear wheel chassis.
Tires or none, Promaster = PFFT! No way for an RV. I see them in plain white panel delivering for Amazon and for that, sure.
Oh, Promaster, being Single Rear Wheel, doesn't get into Dual Wheel Offset (aka Dually Spacing) issues. This spacing works out to the clearance between sidewalls, but it's not specified that way. It's the measurement between two matching features of the mounted rims or the mounted tires. If your tires are a matched pair, measure between one tread groove on one tire and the corresponding groove on the other. Say you get 10-inches. That's the Dually Spacing, and each wheel offset is 5-inches. Space between the sidewalls might be 1/2-inch or 2-inches but Spacing is still 10-inches. There are specs for this, and notice it isn't shown in the linked info in this thread. So you need more information. Sticking with my example of 10-inch measured spacing, you don't want to go to new tires with an 11-inch spacing specified. If you want those, you need new wheels. NOT SPACERS!!! Even if your lugs are long enough, the centering "pilot" part of the hub isn't.
I'd consider taking off on Phil's tire size change. See if LT235/85E will upgrade from LT225/75E by finding the Dually Spacing for those two sizes. You could pick up a little more capacity and still have commonly available tires.

There is a new tire out there (I'll refer to it as the Euro C). it is designed for cargo vans. The Continental tire you link to is one of them. The size carries the C after the designation. Much higher weight rating than a standard LT tire. There only a few manufacturers producing the tire.

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Nexen Roanian CT8. Top four tire sizes in the chart at this link are the Euro C sizes (fourth down is your 225/75R16C)

https://www.nexentireusa.com/tires/suv-light-truck/roadian-ct8-hl

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Michelin Agilis Alpin is about the only other brand available in the US in the Euro C size

https://www.michelinman.com/upload/michelin_us/specifications/specs-agilis-alpin.pdf

The Agilis® Alpin® is designed specifically to fit the latest generation of European-style cargo vans, and provides both 3PMSF certification for winter usage, along with excellent wet/dry traction and wear resistance to allow continued running in the summer months.
The Agilis® Alpin® is designed specifically to fit the latest generation of European-style cargo vans providing excellent winter grip in cold weather without compromising wet/dry traction and wear resistance allowing year round usage.

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These three tires all have the 3195 lb rating at 83 psi, and have a load index and speed rating of 121/120R which is suitable to your MH.

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Not sold in the US market but available in Europe and Mexico is the Michelin Agilis Alpin Camper tire. Tread is designed for Motor Home use.

https://www.michelin.co.uk/tyres/michelin-agilis-camping#tab-tyres-benefits

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These Euro C tires are mandatory on the Ram Promaster as a standard LT doesn't have the weight rating necessary.

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Another alternative is to switch to a 17.5 inch rim and the much heavier tire that is used on it.

https://ricksontruckwheels.com/wheels-ford-e350450.php

Charles

We're happy with Firestone's transforce HT.

Here's the tires that we use on our 2005 E450 small Class C. Their maximum DRW vehicle weight carrying capacity - with the 4 in the rear inflated to 80lbs. each and the 2 in the front also inflated to 80 lbs. each - is 15,240 lbs. ... so they can handle the largest E450 based Class C IF IT'S WEIGHT IS DISTRIBUTED so as to not load the DRW rear 4 tires to more than 9,880 lbs. out of that total of 15,240 lbs..

Here's a source for the tires:

https://www.amazon.com/Michelin-Defender-All-Season-Radial-Tire/dp/B0192KRX7G/ref=pd_lpo_sbs_293_t_2/131-8961605-1803928?_encoding=UTF8&psc=1&refRID=M80NQCQTKHWJW98K3ZYH

Look at this excellent data book on page 34 near the top to see the ratings for the 215/85R16/E size. Do the pressure versus load versus single/dual math to see where 9,880 lbs. and 15,240 lbs. come from:

https://www.michelinb2b.com/wps/b2bcontent/PDF/Truck_Tire_Data_Book.pdf

I use the 215/85R16 Load Range E size - instead of the common E450 stock 225/75R16 Load Range E size - because I wanted a taller tire on our Class C so as to get a little more ground clearance. We do take our Class C off-highway on gravel and rocky roads, so a little bit of extra clearance helps. I use ~80 lbs. of pressure in the rear and ~65 lbs. of pressure in the front. The 80 lbs. of rear pressure is to keep heat due to sidewall flexing from being too great and so I can load up our Class C with no concern for tire over-loading. The 65 lbs. of front pressure is for the same reasons .... however, if I go to 80 lbs. in the front the steering becomes to "light and squirrelly" ... so I drop the front 2 tires down a bit from 80 lbs. to 65 lbs. to get a more solid steering feel.

The rear used to ride a bit harsh using 80 lbs. back there, but that was reduced through use of automatic variable damping shocks in the rear. For a larger Class C than ours, these kind of shocks in the rear may not be needed because of the higher average coach weight back there providing an overall softer ride at whatever tire pressures are being used back there.