I have 20's on my Expy- it rides very smooth, but I have been told that "overboosted" feeling the steering column has, will go away if I reduce the tire pressure.

I don't know what the factory specs are for two reasons.

1.) I only rode on the factory tires/wheels for the first 7-miles that I had the truck, before putting on my 295/65/16's Eagle GT-II's, on some A/R Atlas wheels. (PS- I thought this was the worse tire ever as far as wet road traction & water displacement is concerned)

2.) Factory specs were for a 17" wheel tire combo.

I know the Harley's have like 285/45/20's on them. I have Eagle LS- 275/55/20's. I figured my air pressure requirements would be a bit higher, but I'm just experimenting... I will try Dodge too since my wheel size & tires are optional equipment on the Rams.

Excursy- Right Rear


Excursy Side-


Nice Car-

 

Factory air pressure on the HDs is 35. Someone was saying they put 38 and noticed a difference in ride.

Not sure about an Expy though. My wife has an 02 Expy with stock 17s. The size of it does make it sway more than my truck.

The trucks are also lighter in the rear so that will make a difference as well.

I'd say try different pressures and find what rides well.

BTW, love the pic of that 'stang!

 

wow, that sig is almost as big as daveenders was

anyway, we've got 275/45/R20's on the HD's and the door says like 35 i think, and the tire says like 42 max or somewhere around there. I was running 40 for the 1st 20K miles, but i noticed it was slightly more worn in the middle, but not by very much. I backed them down to 38 so i should be good, and that seems to be what most HD guys run.
I do know that a few guys on here do have 55 series tires, rhdf150 is one of them. maybe look up their profile and drop them a line to see what they say