Multiple Blow-outs

wandering1 wrote:
RV Tire Problems


Tire Pressure
Check your tire pressure when the RV has not been driven for 3 - 4 hours. That is when the tire is "cold". Forget ambient temp, 80psi at 10 degrees F is the same as 80psi at 100 degrees F. If you over inflate or under inflate the tires this can cause the tires to run hotter than normal which can damage the tires and cause tire failure. Stick with the PSI on the side of the tires. No need to turn this into rocket science. Check with the tire manufacturers if you need an education on tire inflation. Tire pressure does rise as the tire temp rises after driving down the road just like it is supposed to which is why you are supposed to check the pressure when the tire is “cold”.

Here's a bit of misinformation. 80psi at 70 deg is not the same as 80psi at 100 deg F. Really? Gasses expand when heated. Tire pressure is standardized at 70deg F. 80 psi at 70 goes to about 74psi at 50 deg F and 95 psi at 90 deg F. This post is giving the same misinformation it complains about.

In my opinion, the best protection is a tire pressure monitoring system. We have a TST 507. It delivers accurate pressure and temperature continuously. We monitor it while we drive. It isn't unusual to see the pressure go from 80psi at 70 deg F to 100psi at 98 deg while we drive on a fairly cool day. According to the manufacturer information (see Goodyear's towing info), always measure and inflate when the tires are cool (as close to 70 deg F as you can get). Never let air out of tires when they are hot. They are designed to handle the higher pressure when warm or hot.

In terms of temperature, according to TST, the only reliable research into heat causing tire failure was done by Michelin and they suggest that below 147 deg F the tires are fine. The TST monitor is preset to sound an alarm when the tires get above the safe temperature.

I keep reading seriously wrong posts about trailer tires. One of the most common misstatements is that LT tires are better for trailers than ST's. Many ethical tire dealers won't install LT's on a trailer. The reason is that trailer tires are designed to stay in one place for long time periods without damage. LT's aren't. ST sidewalls are stiffer (one reason they get so hot is because they are thicker than LT's) to resist the scrubbing caused by the trailer being dragged around turns.

I am not happy about the bad reputation of my Tow Max tires. We have a heavy fifth wheel (13,500 lbs loaded). My Tow Max E rated tires have a load rating of about 3,500 lbs. We have 7,000 lb axles. According to a CAT scale, we have 11,300 lbs on the trailer wheels. That means each tire is loaded to 2,825 lbs. This is well within the tire/axle ratings. Even so, this is a lot of weight. Goodyear makes the G614 trailer tire that has a very good reputation. To buy them, we need new wheels, since ours are 6" and the G614's require 6 1/2. That will have to wait until we can afford the $1,400 or so it will cost.