Blown Tires
Just returned from Overland Expo in North Carolina. On the way down from Michigan we saw six fifth wheel trailers on various parts of I75 and I40 with blown tires. Each one of them had significant d...
Forum Discussion
CapriRacer wrote:No, they're not. That's a common misunderstanding. It's just that (for most of them) the standard pressure/load tables only apply up to 65 MPH. Pressure and/or load rating needs to be adjusted for higher speeds. ST tires can go up to 85 MPH with the proper load/pressure adjustment. Some tires are rated for higher speeds without any adjustment.
Don't forget that ST tires are speed limited to 65 mph and that bit of information generally isn't told to new trailer owners!
If you had ST205/75*15 tires on a 3500 lb axle, you'd need LRC to support a full load (@50 PSI), and that would be good for 65 MPH. If you wanted to go faster, you could go to LRD and up the pressure to 60 PSI, then you'd be good to 75 MPH. Faster? Go to 65 PSI (which gets you 1940 lbs load per tire at 75), then derate by 10% to 1746 lbs load per tire, and hold your axle load to 3492 lbs, giving up 8 lbs of capacity. Then you're good to 85 MPH.
