Community Forums

steppinstone · 04-14-2018, 12:03 PM

Hi I just purchased new steer tire's the plaque in the cab states 70 lbs but on the tire's it say's 110 lbs. Which should I use for adding air???

Magnafique · 04-14-2018, 12:28 PM

Your tire dealer should be able to provide you with the correct pressure, or if you bought them online check with the seller. If none of that works I would go with the pressure recommended on the tire. Magnafique

wingnuts · 04-14-2018, 12:54 PM

What tires did you buy, and what the weight of your motor home. .?

I just went thru this , bought sailuns

Also 110 is probably your maximum pressure

96 Wideglide · 04-14-2018, 01:07 PM

70 psi is correct, as long as the tires are the same exact size as the tires that came on the rig from the factory.

wingnuts · 04-14-2018, 01:28 PM

My sailuns are rated 80 psi minimum and 110 max...

My plaque also says 70 psi but that's for the stock tires that came on it new

Weight of my motor home says to run 80 psi by tire manufacturer but I run 85 to 90 in case my gage is off a little so not to be under 80

veraken · 04-15-2018, 05:53 AM

The tire pressure on the side of the tire is the maximum tire pressure when carrying the maximum weight. To determine what the right tire pressure is for you, you need to weigh your MH. Load your MH as you would for travel, fill you gas and water tanks and then get your MH weighed.

If you can't do 4 corner weighing, this is the procedure to follow:

1. Weigh the coach axles
2. Add 5% to account for possible uneven weight side to side.
3. Divide by the number of tires on each axle.
4. Look to tire chart for your brand to find tire pressure.
5. Add 5 psi for safety

Monacoach · 04-15-2018, 07:27 AM

70 psi will be based on your front axle fully loaded to the gvwr.
so most likely you will be under 70 psi after weighing the coach and checking the chart.

If you choose not to weigh your coach then for now 70 psi would be a good safe choice. Better overinflated then under.

wildtoad · 04-15-2018, 07:46 AM

Do not use the pressure stated on the sidewall unless it matches a) what the RV manufacturer placard states or b) the tire manufacturers chart based on facts as to your axle weights as measured on a scale. For most instances what is on the sidewall is good information but of limited value and should only be used if you have no other information at hand.

steppinstone · 04-15-2018, 08:38 AM

Thanks everyone for the help . I just got a reply from the tire suppler where i purchased the tire's they replied to fill to coaches plaque card..70 LBS

I just didn't want to damage tire's

grindstone01 · 04-15-2018, 08:50 AM

What manufacture made the chassie, GM, Ford? It might be the cab plaque came from the manufacture as a cab and bare chassie of which the 70 psi would probably be correct for a empty frame. The chassie manufacture would not know what the RV builder is adding weight wise to the chassie. Best to weigh the rig and follow tire manufacture recommendations.

Mr_D · 04-15-2018, 09:06 AM

Quote:

Originally Posted by veraken

The tire pressure on the side of the tire is the maximum tire pressure when carrying the maximum weight. To determine what the right tire pressure is for you, you need to weigh your MH. Load your MH as you would for travel, fill you gas and water tanks and then get your MH weighed.

If you can't do 4 corner weighing, this is the procedure to follow:

1. Weigh the coach axles
2. Add 5% to account for possible uneven weight side to side.
3. Divide by the number of tires on each axle.
4. Look to tire chart for your brand to find tire pressure.
5. Add 5 psi for safety

Printed info from the tire manufacturers states that the pressure molded into the sidewall of a tire for vehicles with a GVWR of 10,000#'s or more is the MINIMUM cold pressure to support the MAXIMUM rating of the tire. This allows for the pressure increase due to running temps.

wingnuts · 04-15-2018, 10:17 AM

Quote:

Originally Posted by steppinstone

Thanks everyone for the help . I just got a reply from the tire suppler where i purchased the tire's they replied to fill to coaches plaque card..70 LBS

I just didn't want to damage tire's

I would double check if I were you. ..something don't sound right

I never seen a tire that's rated 110 psi max be able to run 70 as a minimum...assuming you have 19.5 tires on your 36 ft sun Vista

What tires and what size, anyone here can help

RVPioneer · 04-15-2018, 10:45 AM

There's only one way to inflate your tires to the correct pressure.
Weigh your coach.
Refer to the tire manufacturers inflation chart for specific weights.
Inflate to the pressure indicated on the chart.
Inflate cold. Never immediately after driving. Early morning before sun exposure is ideal. Tires exposed to sun can read 5-10 lbs higher than those in the shade.

The guys at the shop are just guessing, unless they weighed the coach.

Do not add 5-10 lbs extra for safety.

RVPioneer · 04-15-2018, 02:34 PM

Quote:

Originally Posted by wingnuts

My sailuns are rated 80 psi minimum and 110 max...

My plaque also says 70 psi but that's for the stock tires that came on it new

Weight of my motor home says to run 80 psi by tire manufacturer but I run 85 to 90 in case my gage is off a little so not to be under 80

If you believe your gauge may be that inaccurate, how can you be sure the 90psi reading isn't closer to 100 rather than 80?

Compare the reading on your gauge with several others at a tire shop or a with a few neighbors at the campground. If the others read the same and yours is off by more than 1-2psi, throw it in the trash and buy one that is accurate. Then trust the reading. Overinflated is not an ideal condition.