Tire Pressure

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Weewun

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Have just purchased a new Monaco Diplomat and have two questions.

1. Having read the manual I realize that I need to weigh the individual wheels in order to determine the proper Tire Pressure.  Have asked Lazydays where to get it weighed and they say there is no place in the area.  I will be leaving here and going to Miami area and am asking if anyone knows of a place between here and there that I can get it weighed and what is a fair price would be for such service.  Route shall be determined by input.

2.  Being an avid Forum reader, I recall someone saying their new Camelot handled terribly because of to much pressure in the front tires.  I do realize that he weighed his MH to determine the correct pressure but I will not have that opportunity.

I have measured the pressures and they are 115lbs front and 90lbs rear which, according to the sticker in the MH, is the pressure for the maximum GVW.  I do not travel with Fresh, Black or Grey fluids and the Fuel and LP Gas will be full.  I have less than 1,000lbs of personal 'stuff' and less than 400lbs in passengers (very small Mother-in-Law) and I tow 4-down.

All the above leads to my second question, "Should I do anything about the front Tire Pressure (seems to high)?????

Will appreciate all input.
     
 

Alaskansnowbirds

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Camp Verde, AZ
Weewun said:
......Have asked Lazydays where to get it weighed and they say there is no place in the area.......

Look in the yellow pages for public scales. If none are listed look for moving companies. Many of them have scales. If the moving companies don't have any scales, look for truck stops or gravel operations. Many of them will also have scales.

Where ever you get it weighed, tell them you don't need a certified weight and it will cost just a couple of bucks.

Just checked and the Flying J truck stops at Dade City (I-75 exit 285) and Seffner (I-4 & SR 579 Exit 10) both have a scales.
 

Tom

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I see Don gave you several good options for getting the coach weighed.

Weewun said:
Should I do anything about the front Tire Pressure (seems to high)?????

Not until you can get the front end of the coach weighed.

It's really too bad that these dealers don't take the time to educate themselves about this subject and to pass the knowledge along to their customers. Ours was the Camelot that left the dealership with tires inflated to 140 psi (I wasn't driving and didn't see the coach until it was delivered out of state). When I returned to the dealership a few days later, I noticed that there was a scale right next door. When I talked with the dealer's tech who had inflated the tires, he was clueless and insisted they be inflated to the max pressure on the sidewalls.
 

rtaylor

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Dec 20, 2005
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Tom I don't know where he got the info to inflate to max pressure. But as techs we are educated to the proper tire pressures and the factory tells us to inflate to what the Rating plate next to the driver seat says. That way when the consumer sets them differently and has complaints about drivability they can say the tires weren't set to ratings plate. Please keep in mind what they tell you and what they tell    us can be two diffrent things
 

Tom

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I don't know where he got that information either. But, when I checked the tires, he had them inflated to 140 psi. The rims are rated at only 120 psi (that might be 125 psi). Steering was definitely a white knuckle job until I weighed the coach and correctly set the pressures.
 

BernieD

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Goodyear, AZ
rtaylor said:
Tom I don't know where he got the info to inflate to max pressure. But as techs we are educated to the proper tire pressures and the factory tells us to inflate to what the Rating plate next to the driver seat says. That way when the consumer sets them differently and has complaints about drivability they can say the tires weren't set to ratings plate. Please keep in mind what they tell you and what they tell    us can be two diffrent things

R

I just had new tires installed on my coach and visited another tire shop when one of the tire valve stems failed. In both cases, the technicians wanted to air the tires up to the sidewall "rated" pressure and gave me a lot of resistance when I insisted on lower pressures based on 4 wheel weighing and calculated by the tire manufacturer. The pressures listed on the "Ratings plate" and the factory are based on maximum tire loads, what the tires should be aired up to IF the coach was loaded to it's GVWR. Since neither the factory nor the installer know the actual travel weight of the coach, they go with the "Ratings plate" to be safe. But the ratings plate doesn't say what pressures the tires should be run at, just that the axles are rated to carry the maximum load at those air pressures.

If the coach has been 4 corner weighed and the tires set at the tire manufacturer's recommended pressure for those weights, the coach should achieve it's optimum driveability. If it isn't, don't blame the tire pressures, there is something else wrong.
 

King

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MA
The simple reasoning for using either the sidewall rating pressure or the manufacturer's recommended pressure is the fact that tires underinflated for the load have a bad habit of catastrophic failure.  You definitely don't want that.  I would use the manufacturer's recommended pressures "ratings plate" until you can get an accurate weight per axel.
Art
 

Ned

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In Tom's case, inflating the tires to 20psi over the wheel rating is not only as dangerous, but irresponsible.
 

Ron

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Home is where we park it
The pressure found on the tire sidewall is the required pressure when the tire is loaded to its maximum weight capacity. I.E a popular Goodyear tire used on motorhomes is the 275 /80R22.5 ?per the Goodyear tire inflation chart this tire maximum load is 7160 in a single position or 6610 in a dual position at an inflation pressure of ?125 PSI and this is shown on the tire sidewall. ?First thing to note that in many cases such as our Eagle the maximum pressure for the wheel/rim is 120. ? Our rear axle is rated at 20,000 LBS per the chart the maximum required ?pressure for our tires is 90 PSI for a tire with a load of 5080 LBS. This is 30 PSI less than the maximum tire pressure found on the sidewall for a load of 6610. ?Interesting that the inflation pressure of 125 is for a load of 6610 on the tire X four tires = 26440 lbs on the axle. ?This exceeds the maximum allowable single axle load in any state. ?

Now per the tag on the Eagle at maximum weight we should have 115 PSI in the front tires. ?However, having had the coach weighed at all tire positions we are not loaded to maximum so per the tire manufacturers (in our case Goodyear) the correct pressure is 100 PSI for the fron tires and 90 PSI for the rear.

Now IMHO it is much better to follow your tire manufactures recommendations for your tires as you have them loaded. ?The ONLY way to determine what is correct is to get weighed. ?Without knowing the normal weights you travel at there is no way to properly determine the correct tire pressure for your rig.
If you do not know how much your rig weighs then use the recommended pressure until you get weighed but never never never exceed the maximum wheel/rim pressure and don't put off getting weighed.
 
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