I think the low profile, vs. standard profile, accounts for most of the harder ride.For what its worth my XT6 was delivered with 40 psi in the 20's. I went with 36 psi as stated on the jam and it still rides harder than my XT5 with 18" tires. You think 31psi is the magic number? I'm ready to try it.
Having more rubber on the sidewall will improve ride. Also it is much easier on suspension parts like shocks.I think the low profile, vs. standard profile, accounts for most of the harder ride.
My wife’s $32K 2013 Hyundai Santa Fe sport with 18” standard profile tires rides smoother than my $65K 2017 XT5 platinum with 20” low profile tires.
There is no minimum pressure stated on the tire. The Cadillac warning light illuminates on the dash at 29 psi and below. Running 31 psi improves ride quality significantly with 18" tires. I would expect a dramatic improvement for XT5s with those low profile 20" rims. Actually, I had the idea of reducing pressures while driving my friend through the park over minor speed bumps. I thought, "Well that's the end of her being impressed by this Cad!" At 36 psi, it thumps over bumps like a truck on leaf springs. So said Consumer Reports.