olly72
Pembroke pines, fl
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Hi All: Just want to make sure I'm right about the tire pressure. I have a 32 H Sunrise itasca with goodyear tires. I weighed the coach and came up with these approximate weights when fully loaded. Front right 3600 Front left 3510 Rear left duals 6910 Rear left duals 6830. I read the goodyear chart and it suggest 70 psi for the front tires and 80psi for the rear duals. If someone with a little more experience could validate this I would be most appreciative
2008 Itasca Sunrise 32H
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Twomed
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Need to post the tire sizes so we can check the inflation tables. 
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CapriRacer
Somewhere in the US
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It is a common old wive's tale that you should use what the tire load chart tells you. You should use MORE - and I advocate 15% more load carrying capacity (you'll need the chart for that).
Generally, that means the tire would be maxed out. So the rule of thmub OUGHT to be, use the maximum pressure listed on the sidewall of the tire.
Here's more detail:
Barry's Tire Tech - ST Tires
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Visit my web site: www.BarrysTireTech.com
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wny_pat
Western NYS
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Oily,
Did you notice that the psi for single tires and for dual tires is different on the chart?
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wny_pat
Western NYS
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Son of Norway wrote:That doesn't seem like enough tire pressure to me, but you should look at the sticker on your motorhome for guidance on tire pressures rather than just a tire maker's chart.
Miles
Here is a link to the proper way to determine RV tire psi:
RV Safety - Tire Load and Inflation Ratings. This is very important as I understand that at least 50% of existing RVs on the road exceed at least one safety weight rating! So you actually need to weight each side of each axle to find out the proper psi!
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Son of Norway
Denver, Colorado
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That doesn't seem like enough tire pressure to me, but you should look at the sticker on your motorhome for guidance on tire pressures rather than just a tire maker's chart.
Miles
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michahicks
Waterford/Gaylord, Mi
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CapriRacer wrote:It is a common old wive's tale that you should use what the tire load chart tells you. You should use MORE - and I advocate 15% more load carrying capacity (you'll need the chart for that).
Generally, that means the tire would be maxed out. So the rule of thmub OUGHT to be, use the maximum pressure listed on the sidewall of the tire.
Here's more detail:
Barry's Tire Tech - ST Tires
Sorry, but if the coach is weighed loaded, ready to go (w/all gear, full fuel and water, etc.), I'm not seeing the necessity to add much in the way of a "safety factor"? I'm weighing the coach so I know what it weighs, enabling me to accurately determine the correct tire pressures - so there's no guessing/estimating involved, and running the tires at maximum inflation (as indicated on sidewall) just isn't necessary. This also provides assurance that it's not going to be riding any harsher than necessary, and handling isn't being compromised in any way.
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Dale.Traveling
Newport News, VA
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I looked at this from multiple directions for my coach. Between what tire manufactures, coach builder, chassis builder and such. All the numbers boiled down to the coach builder's inflation recommendation, if, I use the correct tire size and do not exceed the chassis loading limits. The pressures listed reflect if I was loading to my chassis limit. I did added a few pounds thru trial and error to improve the ride and handling.
For the OP's 2008 Itasca 32H Sunrise it came on four different chassis version which further came with either 19.5" or 22" tires. Without knowing the tire size can't say what the correct pressure should be. As such I would go with whatever Itasca recommends (if you are using the correct tire size and load rating) and add a couple of pounds for peace of mind. Use that number as a 'Not to Go Below' pressure and the side wall number as the 'Not to Exceed'. Play with the pressures a bit between those to numbers to give you the best ride and performance. Remember to keep the pressure in each duals set the same and all the published numbers are cold pressure. Drive any distance and the tires are no longer considered cold.
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CapriRacer
Somewhere in the US
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michahicks wrote:Sorry, but if the coach is weighed loaded, ready to go (w/all gear, full fuel and water, etc.), I'm not seeing the necessity to add much in the way of a "safety factor"?.....
I'm not saying adding "much". I am saying having some - and based on the number of ST tire failures, it appears that more than the normal is needed.
michahicks wrote:.... I'm weighing the coach so I know what it weighs, enabling me to accurately determine the correct tire pressures - so there's no guessing/estimating involved, and running the tires at maximum inflation (as indicated on sidewall) just isn't necessary. This also provides assurance that it's not going to be riding any harsher than necessary, and handling isn't being compromised in any way.
Look at it this way: Which is less likely to result in a tire failure? - a tire running AT capacity, or a tire running UNDER.
Try looking at the lastest pickup trucks being offered. Compare what the load carrying capacity of the tires are (at the pressure listed in the placard), against the GAWR's (Gross Axle Weight Rating). Those folks have had to learn a very bitter lesson - and I would suggest that folks follow their example.
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ArchHoagland
Clovis, CA, USA
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CapriRacer....How long have you been manufacturing tires?
Where is your test facility?
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