tire pressure

PokerCamper wrote:
I have Power King Towmax ST 225/75R15 D rateds (yep, Chinese bombs manufactured in late April of 2011) on the 29' 5'er we just bought. They're 2540# each, but my Cougar XLite has a GVW of just under 7,000 dry. The treads passed the penny test and have less than 8,000 miles on them, so I'm trying to get through this season and replace them with LTs next spring.

We're leaving for a 2 week vacation that will add about 1,200 miles round trip. Am I good running them right at the 65 psi (measured in the morning, of course) they're rated for or should I go a little lower since I'm towing light. I tow with tanks empty and though I haven't weighed it, I'd be surprised if we're over 8K pounds with payload.

I would give the sidewalls a close inspection. I'm replacing mine because of this. The tires on the south side of our storage spot look like this. The tires on the north side look perfect with no cracking at all. Same tires as yours, maybe a little older.

PokerCamper wrote:
I have Power King Towmax ST 225/75R15 D rateds (yep, Chinese bombs manufactured in late April of 2011) on the 29' 5'er we just bought. They're 2540# each, but my Cougar XLite has a GVW of just under 7,000 dry. The treads passed the penny test and have less than 8,000 miles on them, so I'm trying to get through this season and replace them with LTs next spring.

We're leaving for a 2 week vacation that will add about 1,200 miles round trip. Am I good running them right at the 65 psi (measured in the morning, of course) they're rated for or should I go a little lower since I'm towing light. I tow with tanks empty and though I haven't weighed it, I'd be surprised if we're over 8K pounds with payload.

IMO run the max psi on sidewall. My tires are the same size and the tires say 65psi and so does the sticker on the side of the 5'er. 9000lbs loaded, 6000 miles and all looks good.

2540x4=10160lbs. Minus the TW of 950lbs and you have 7050lbs on the tires. That's 3110lbs or a reserve of 777lbs for each tire. Well under the max load rating. The less weight on the tire the longer it will last. I'd be comfortable putting 1200 miles more on them.

I have Power King Towmax ST 225/75R15 D rateds (yep, Chinese bombs manufactured in late April of 2011) on the 29' 5'er we just bought. They're 2540# each, but my Cougar XLite has a GVW of just under 7,000 dry. The treads passed the penny test and have less than 8,000 miles on them, so I'm trying to get through this season and replace them with LTs next spring.

We're leaving for a 2 week vacation that will add about 1,200 miles round trip. Am I good running them right at the 65 psi (measured in the morning, of course) they're rated for or should I go a little lower since I'm towing light. I tow with tanks empty and though I haven't weighed it, I'd be surprised if we're over 8K pounds with payload.

Good information to know because our E rated tires also say 80PSI, but tire shop says to put them at 75, RV shop says to put them at 80. Seems the RV shop is right by all the responses here. Regarding one comment here of not worrying about pressures when towing underweight??? Sort of an oxymoron because one should not tow overweight, although it's done all the time, but also, underinflated tires can fail as easily as overinflated no matter the load.

laknox wrote:

lilcountry wrote:
I have a question about tire pressure. My load range E tires are rated for 80 psi. I know that once I start moving, especially in warmer weather, the psi will increase. Should I start with 80 psi, or should I start with a lower pressure? If so, what do you recommend?

Side of the tire says "Max 80 psi cold", so that's where you start, unless you're very lightly loaded, then you can go down in pressure. They know that the tires will heat up and are (supposedly) designed to handle this.

Lyle

X2. Fill 'em up cold in the morning, they're good to go the rest of the day. I don't worry about pressures while towing underweight, and have not experienced any unusual wear in the center of tread.

mine were at 92 psi/102 degrees coming home from VA this wknd. no problems.

When towing, I pump mine up to 80psi when they're cold (before rolling for the day), that's the max psi and they will carry their max payload with that... and while I am not loaded to max payload of the tires, I still air 'em up to 80psi. Carrying less payload isn't going to hurt them; yea the ride may be stiffer, but I'm towing heavy anyway so it's not that stiff, and the tires feel more stable since there is less flex on them. As far as more wear on the center of the tire, I haven't experienced that.

lilcountry wrote:
I have a question about tire pressure. My load range E tires are rated for 80 psi. I know that once I start moving, especially in warmer weather, the psi will increase. Should I start with 80 psi, or should I start with a lower pressure? If so, what do you recommend?

Side of the tire says "Max 80 psi cold", so that's where you start, unless you're very lightly loaded, then you can go down in pressure. They know that the tires will heat up and are (supposedly) designed to handle this.

Lyle

Thanks for the replies. I just didn't know if the heat expansion was factored in by the manufacturer.

lilcountry wrote:
I just didn't know if the heat expansion was factored in by the manufacturer.

It would be a nightmare if they didn't!