And your recommendation was greatly appreciated, Chris!
I was unfamiliar with Nexen tire's offerings in this size until you identified it.
The CT8 HL that you use is the OEM tire that Stellantis fits to the Ram Pro Master, in the 121/120R load index that you are highlighting. When a tire is produced as original equipment for an OEM vehicle manufacturer, it stands to reason that the CT8 HL has been put through an extra layer of engineering and vetting by the vehicle manufacturer, for the sake of their own liability. That says that while Nexen may not be as well known of a brand as Michelin or Goodyear, that particular CT8 HL Nexen tire has been approved by VW and Stellantis for their new vehicle brands to ride on it.
I'm not a tire expert either, so the questions that PNichols asked above are questions that I was curious about as well. Where a given brand of tire produced in two iterations for the same application and usage has the same material weight, why would one tire have a higher weight capacity than the other? What makes the higher rated tire stronger, even while having less material weight?
Michelin claims to use over 200 different raw materials to produce a tire. while another tire manufacturer claims to use only 17 different materials. While it can be assumed that Michelin, being the oldest tire company, and having introduced significant innovations to the industry such as radial tires, is more advanced... some of the ingredients introduced into tires today are to make them more environmentally friendly at end of life, and that sophisticated soup of materials may not necessarily translate into tire longevity.
RV tire purchases are not routine for the long term RV owner who does not regularly trade in their RV, but rather are a once every 7 to 10 year expense now exceeding $2,000.00 to replace tires that have plenty of tread left but simply aged out. Blow outs are a much bigger deal on an RV than in a car, for reasons which SJ-Chris already mentioned. These factors inspire more questions on the selection of RV tires versus daily driver tires that may see more frequent replacement.
Earlier, I failed to mention that Firestone, the manufacture of the Steeltex R4S that used to be Ford's OEM tire on the cutaways 20 years ago, now offers the Transforce CV tire in the 121/120R load rating.
Unlike the F-53 Class A motorhome chassis, or any given modern day 1 ton and higher pickup or chassis cab, the Ford E-Series cutaway chassis challenges the limits of the Ford recommended LT225/75R16E tire size. I began this thread asking if any Class C owners have changed tire sizes, whether it be for increased tire capacity margin, increased ride height/ground clearance, increased approach/departure angle, increased tire contact patch, or decreased contact patch to penetrate through light snow to the ground.
The relatively recent emergence of the C-Metric tire being offered in the US, with higher load index ratings, have broadened the weight capacity margin... but a tire still has to do other things besides carry weight.
Wet traction comes to mind. Not skidding out in the rain. Not spinning wheels and burrowing in on grassy slimy surfaces at unimproved campground. That sort of thing. A tire must still be a tire in all other respects besides carrying weight.
It appears that the ETRTO standard calls for Curb Guards (anti abrasion buttresses on tire side walls where they might repeatedly grind against a sidewalk curb in urban parcel delivery applications) in all C-Metric tires, and this is another benefit that is useful when navigating Class C RV's through destination cities.
Asking about what tires people use and reciprocating the favor by posting what tire explorations I have made, is part of the process of learning, and I appreciated the opportunities to learn from you.
