Wheel diameter

A larger wheel may not make your hitch taller, the overall diameter of your tire is what matters. They may be exactly the same.

I suggest a basic TV tire and wheel tutorial.

I agree with the above. What are the two different tire sizes? That will give you the height difference. Other than that you could research the availability and price differences in the tires come replacement time. In all practical terms probably not much difference other than looks.

18" tires are cheaper to replace and more readily available than 20" tires. Same weight ratings too, at least on the sizes you available on Ram trucks.

Is someone accusing me of doing something only for looks? lol

IdaD wrote:
18" tires are cheaper to replace and more readily available than 20" tires. Same weight ratings too, at least on the sizes you available on Ram trucks.

I agree.

There a lot of tire choices available in 18". 20"s tend decrease the height of the sidewall, which has a place (like on my ZL1). However in a pickup towing a lot of weight and or going off road, I prefer having more sidewall verse less.

ksss wrote:

IdaD wrote:
18" tires are cheaper to replace and more readily available than 20" tires. Same weight ratings too, at least on the sizes you available on Ram trucks.

I agree.

There a lot of tire choices available in 18". 20"s tend decrease the height of the sidewall, which has a place (like on my ZL1). However in a pickup towing a lot of weight and or going off road, I prefer having more sidewall verse less.

X3
I would be more worried about tire capacity and availability than size stick with the 18’s.

6 in 1 half dozen the other anymore. There is endless selection of 20" truck tires on the market and comparable sizes really arent much if any more expensive.
That's now a myth. Just checked Toyo AT's comparable 18/20" common truck size 285-60-20 and 285-75-18. The 20s were $14 more per tire.

If towing heavy, the same diameter tire, 20's will actually ride just a bit more stable with less sidewall flex.

Bottom line it's down to almost 100% personal preference and the price/performance apples to apples is almost identical.
With a greater sidewall height, though, 18s will typically have a higher load rating for the same diameter.

I am always amused by these discussions , What difference can it make , it is just a tire on a truck .

Doing ther math, 285/75R18 has a diameter of 34.83". The 285/60R20 has a diameter of 33.46". The difference is 4%. Theoretically, the 20" tires should accelerate better and stop better. The 18" tires might allow for better fuel economy. Your truck should sit 5/8" lower with the 20s, if all other things are equal. I trust Grit Dog that these are the sizes offered.