So then the OP would have to have load range D tires. There are several factors to consider before resorting to racist comments....
ST tires are rated for max. 65 mph. It's not always easy to max. out at 65 mph. How often do you (to OP) drive at or over 65? Be honest. It's sooo easy to cruise higher than 65, esp. if your "sweet spot" is a little higher. How accurate is the speedo on your TV? Maybe it is reading low? 65 isn't a magic number but why stress the tires running exactly at 65 or over 65 a lot? Perhaps ST rated tires should be redesigned and made to run up to 70 mph. I bet a lot of RVers tow over 65.
Heat is not a good thing for tires. If you live in an area or travel to places where it is hot, that's not good for tire life. If just parked it's not good. If you set your tires for 65 psi, then they will get much hotter while travelling, and more so if you drive over 65 mph. How often do you check the tire pressure after travelling a long distance in the heat? In the summer you may want to lower the pressure a bit before you drive off and monitor after you've been driving a while.
UV rays are baaad for tires. Many MH-ers use tire covers to protect their expensive tires. If you park in the direct sun a lot and with heat on top of that, perhaps tire covers might help?
OP says the tires are 7 years old. That's playing with fire on any ST rated tire. If you tow a lot over 65 mph, if you don't routinely check for over-pressure in the summer, and if the tires sit in the direct sun a lot, then you are just asking for trouble.
This is my understanding from reading RV forums for a while.
As for the unkind (racist) words about the Ch*nese, we are a large part of the problem. You can't blame the Chinese people as a race. We demand cheaper prices and thus we enable Chinese manufacturers to produce lower quality products. How often do you shop on the basis of quality, look for domestic made products first, and willingly pay the highest price in an attempt to get better quality? We demand lower prices on our RVs, so guess what? The RV manufacturers put the cheapest components on them.
Ever watch Shark Tank? The investors are always saying to new entrepeneurs to take their new product/invention to China to make them for a lot less so that their profits will be higher. That's become the mentality here. Too bad, because we are damaging our own economy in the process. No wonder jobs are disappearing here. But we keep enabling the Chinese manufacturers. Can't blame the Chinese for intentionally producing inferior quality products. Look at yourself in the mirror first.
Also, a big part of the problem here is the lack of governmental safety and design standards in the US in the RV industry. The automotive industry is well covered. Why is the RV industry such a mess? There's all sorts of quality problems with RV components due to lack of enforceable regulations and standards (no, RIVA is not enforceable, not public and is self-serving). We demand lower prices and substandard parts by comparison to other industries (automotive is a good comparison) have no barrier to entry into North America. If you were a Chinese manufacturer and wanted to expand your market into the US, what would you do in the absence of adequate regulations? Make cheaper stuff if you can get away with it, which would more than likely result in poorer quality. China doesn't have very good safety and design regulations of it's own like we do here which also doesn't help.
People can make all the China bomb remarks they want, but racist ones are just so wrong. You can't blame individual Chinese people - they're among the nicest people around that you can meet. Take a trip there and find out what it's like. Take a really good look in the mirror first and ask yourself why you buy Chinese products all the time, ask yourself how inferior quality products are allowed to be sold here, and ask yourself what you are doing to workers here by buying so many Chinese made products. We need to clean up our own backyard first from the government level down to the individual level.
I was shopping for a new heavy duty shovel yesterday and the label said "Made in the US - with parts imported from China". Really??? That's a new one for me.
I once traveled into the US to help a friend install a transmission in his car. The US border guard asked me why I was entering the US and I told him. I almost got sent back home and banned from the US because he said that the US does not like anyone taking jobs away from US citizens. I read about a Canadian music student that was trying to go to New York to play in a band there to get experience. She was refused entry because they said she would be taking a job away from an American. They are really strict about this for Canadians entering the US. But Americans buy all the Chinese made goods they want and hurt the economy as a result. I am confused here....
I thought Goodyear Marathon tires would be a good option, but then I've read that they are being made in China and *may* be no better than the rest of them. Is there an ST tire made in the US with 100% US made material? What happened to all the tires being made in Akron? You can't blame the Chinese for this alone.
Back to OP - all the OP can and should do is study the RV forums and choose what seems to be the better quality tire and type, take care of them after that and then replace them at the recommended interval. Maybe move up to an LT tire.
