Need tires on my Ram Tow Vehicle.

GordonThree wrote:
I was considering the same, switching my grocery getter from 20 inch passenger car tires to 18 inch truck tires (range E)

I'm not a fan of how these factory low profile 20" tires handle my trailer, and with a max sidewall of only 51 psi, they're not cut out for towing.

Both 18 and 20 inch rims are a factory option, so the computer must have an electronic switch somewhere to reprogram the wheel size?

There’s plenty of 65psi tires in your size.
Not against E load tires, but you’re not likely to carry enough Weight to actually need an E load tire.
20s are great for towing. Less sidewall = less sidewall flex.