[ShrimpBurrito]

I suspect that PSI ratings correlate to weight ratings, so my GUESS is that for any wheel rated for 1870 lbs, they will all have a specific pressure rating. If you want more than that, you need more weight capacity.

But that may not be universal, I don't know. See if you can find pressure ratings for a bunch of 1870 lb rated wheels -- if they're all the same, that might be your answer.

But if I were you, I'd get 15" wheels and tires. That resolves the issue, and also gives you a far greater safety margin. Blowouts are expensive (far more than a cost of rims and wheels), always happen at the least convenient time and place, are a major safety hazard, and are sure to spoil your trip.

Dave