I know there are lots of threads about this, but I'd still appreciate if someone could double check my understanding - it seems like the tire pressure I could/should(?) use is much lower than the sticker on my motorhome.
I've got a 24 foot motorhome with no slideouts; it's a 2011 on an E350 chassis. Current tires are LT225/75R16 Michelin Agilis CrossClimate. I don't know what it came with originally.
The stickers on the vehicle show the recommended pressures:
Front - 75 PSI
Rear – 65 PSI
and weight rating:
GVWR – 12,500
GAWR Front – 4,600
Rear – 8,500
If I look at the Michelin pressure chart for that tire:
I think it shows that at those pressures the front could support 2,950 pounds on each side (~6,000 total) and the rear dualies could support 5,070 on each side (~10,000 total). Looking at that, it seems like those pressures are pretty high, maybe the tires that came on it originally used very different pressures?
I weighed the RV today with the gas, fresh water, and propane tanks full, some stuff in the cargo area, myself, and that's about it. On a trip I'll have a wife, two dogs, a 10 lb cat, and our stuff...
Front - 3,660
Rear - 6,780
I can't imagine the extra weight for a trip would come close to 1,000 pounds, but I'll use that as a number(?) and call it 40% front and 60% rear?
4,060 in front
7,380 in rear
Then maybe guess that the side might be uneven, as much as 53/47 (?) so the max weight on a side would be:
2,152 on one side in front = 50-55 psi
3,911 on one side in rear = 45-50 psi
Looking up those weights in the inflation chart gives:
Front - 50-55 psi
Rear - 45-50 psi
But I want to make sure that when it's colder than when I fill up the tires, I don't drop below that pressure. So maybe add 10% (?)
Front - 55-60 psi
Rear - 50-55 psi
Those numbers are still pretty far below what's on the sticker. Am I missing something?