Tire pressure question

[La.Paul]

I have a 2003 sea breeze 8311 lx and the specs posted in the coach call for 85 lbs air pressure in all tires. I replaced all tires last year, and the new tire specs for a load of 3640 lbs per tire front and 3415 dual rear ( which would give me 7280 on front axle, 13,260 on rear) is 80 lbs. I think my ride would be smoother with 80 lbs. Total weight of coach is under 18,000 lbs, with just over 6000 on front axle. My replacement tires are not same brand as original. Would it be best to use 80 or 85 lbs?

[RickO]

So the big question is, have you actually weighed your rig so you know what your axle weights are?

Rick

[Midniteoyl]

Use what your current tires call for...Use current coach weight ready for travel, not the placard.. You can bump it up 5-10 psi for safety and overhead, but never lower..

[Richard S.]

With the information you provided and checked against the Goodyear RV inflation table, stay at 85lbs till you get accurate corner weights. Factory tires were 245/70/19.5 range F

[Midniteoyl]

Originally Posted by Richard S.

With the information you provided and checked against the Goodyear RV inflation table, stay at 85lbs till you get accurate corner weights. Factory tires were 245/70/19.5 range F

I'm noticing that Goodyears recommendations are actually higher in some (most) cases..

There was another thread with 16" coopers that was recommended they be 20 PSI lower than Goodyears..

Now I'm wondering "Why?'

[La.Paul]

Weights posted are actual weights at the scale, fully loaded, full fuel, 3/4 water tank full, propane full.

[tropical36]

Originally Posted by Midniteoyl

Use what your current tires call for...Use current coach weight ready for travel, not the placard.. You can bump it up 5-10 psi for safety and overhead, but never lower..

X2 and be sure to weigh first, ready for travel including people, then add min. 10psi for a cushion.

[BarryN514]

Still playing with my tire pressure. When we bought the coach less than a year ago, it had new tires on it and a few days later, check the tire pressure and it had 110 lbs in it. The max tire pressure listed on the tires is 125 at cold. The coach seemed to steer too easy. I weighed the coach and total weight is approx 16,000 lbs. the card in the coach states with max gross weight it should be 85 lbs. I have now lowered my tire pressure to 95 lbs all around and it seems to steer better. Someone told me that I should run lower pressure in the rear. Not sure if that is correct?

[Midniteoyl]

If you weighed your coach, what are those weights? You can take those weights and look up the load chart for your tires and see exactly how much air you should have. From the sounds of it, somebody bought a waaayyy over strength tire. The last owner of mine did the same and I am running the minimum PSI allowed for those tires and am still at what the placard says is MAX..

[tropical36]

Originally Posted by BarryN514

Still playing with my tire pressure. When we bought the coach less than a year ago, it had new tires on it and a few days later, check the tire pressure and it had 110 lbs in it. The max tire pressure listed on the tires is 125 at cold. The coach seemed to steer too easy. I weighed the coach and total weight is approx 16,000 lbs. the card in the coach states with max gross weight it should be 85 lbs. I have now lowered my tire pressure to 95 lbs all around and it seems to steer better. Someone told me that I should run lower pressure in the rear. Not sure if that is correct?

You have to at least weigh each axle, use a tire inflation chart and then add 10psi for a cushion, especially if you're not weighing each wheel and one side of the coach could be hundreds of lbs more than the other. Even a 15psi cushion isn't excessive.
As for those who pump max sidewall pressure ratings, no matter, remember that newer tires can withstand a lot of pressure, so and especially with an older rig, make sure you're not exceeding the wheel pressure. An exploding tire will put you in the hospital and a exploding wheel will most likely put you in the morgue, although I've never heard of it. Some of the older 19.5" wheels have a 90psi max rating, so check it out first.

[BarryN514]

I had the coach weighed and the front was 5,750 and the rear was 9,860, total weighted is 15,600. The tires are Dynatrac and they do not have a inflation chart that I could find. I am a few thousand pounds under max gross weight for my MH.

[Midniteoyl]

Originally Posted by BarryN514

I had the coach weighed and the front was 5,750 and the rear was 9,860, total weighted is 15,600. The tires are Dynatrac and they do not have a inflation chart that I could find. I am a few thousand pounds under max gross weight for my MH.

Dynatrac is made by Double Coin for distribution under American Tire Distributors as a private label. Use the Double Coin load chart..

http://www.doublecoin-us.com/files/r...ationchart.pdf


What size do you have?

If 225/70R19.5, then 75psi front and 65psi rear would be the minimum..

If 245/70R19.5, then the minimum allowed psi of 65 all around would work..

Again, I would bump both up by 5psi for extra safety overhead..

[tropical36]

Originally Posted by BarryN514

I had the coach weighed and the front was 5,750 and the rear was 9,860, total weighted is 15,600. The tires are Dynatrac and they do not have a inflation chart that I could find. I am a few thousand pounds under max gross weight for my MH.

Any chart will do and if your sizes are what has been suggested by Midniteoyl, then what you choose to add for a cushion is up to you, keeping in mind that you don't know how much weight is on one side or the other. I like 10 - 15psi extra and round it off so as to keep them the same. Also don't worry about ambient temp changes like when we moved between Death Valley and Yosemite NP within a couple of days.

[RickO]

Originally Posted by tropical36

Also don't worry about ambient temp changes like when we moved between Death Valley and Yosemite NP within a couple of days.

I generally agree with this but just yesterday had to break down and air 'em up. We left Phoenix a bit over two months ago when it was 112* and now we're in New Hampshire "Leaf Peeping". When I fired it up for a travel day yesterday, my TPMS began squawking and all six were down at least 10 lbs.

It was 51* and naturally raining.

Rick