What should the PSI be in the trailer?
I have a trailer which has Sailun G rated tires. The maximum PSI of air is listed as 110 PSI. I was carrying 90 PSI but recently was told that the maximum PSI, that is 110 PSI is the amount of air I ...
Forum Discussion
fj12ryder wrote:
Actually Keystone "derated" the axles to get the tires to meet the tire/axle rating. They are 7,000 lb. rated axles, according to Dexter when I checked with them, but Keystone "derated" them to 6,800 lbs. so the "E" rated tires, at 3,400 lbs. each, would work.
How's that for working with the numbers. And a CYA.
Keystone and a lot of other RV trailer manufacturers got into a "catch 22" with those 7000# axle certifications. The easiest way for them to remedy it (IMO) was to deduct a couple of hundred pounds off the trailer's cargo capacity and derate the axles which they are allowed to do. The culprit is the ST235/80R16E tires. Different tire manufacturers have used different load capacities for that identical sized tire. 3420# and 3520#, both at 80 PSI MAX. The 3420# tire does not qualify for use as OEM on 7000# certified axles.
Reason: Elsewhere in the FMVSS there is a standard that says when two identical tires have different maximum load capacities they automatically default to the lower rating.
