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:CALandLIN wrote:It's not really a "Catch 22", all they had to do was put tires on that would meet the axle specs. Which now is getting to be very common. You see quite a few "G" rated LT/ST tires on larger 5th wheels.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.
But rather than go to the expense of putting real tires on these heavy, tall trailers, they put on flimsy "E" rated ST tires and "derate" the axles so they can get away with it. What a racket.
The "catch 22" was; consumers already had the trailers. Look at it from the trailer manufacturer's point of view. Lower the cargo capacity and put on new certification labels with adjusted GAWRs or recall all mislabeled trailers and put on new tires.
