Tire Pressure

[wschneid]

I have a 2000 24' Sunseeker with the Ford E450 chasse. What tire pressure do you recomend?

Bill Schneider

 

[Chuck_S]

The tire pressure is specified on the placard on the door jam in all my vehicles. No reason to deviate from that.
-- Chuck

 

[5er_tom]

Actually yes there are reasons to deviate. Full inflation (as on the door jam sticker) on the front tires is often too much pressure and can cause “wandering” as one drives.

The proper way to determine how much tire pressure, both front and rear, is to weight the RV with it loaded for travel. Then, look up the tire inflation chart for your tire size and set pressures accordingly.

For my RV I run the fronts ten pounds under what the sticker suggests, and it is a much better drive as the wandering is minimal.

 

[NavyLCDR]

49% of the answers will be to inflate what the placard on the doorframe of the vehicle says, 49% of the answers will be to inflate the tires to the maximum that is listed on the side of the tire, 2% will tell you to weigh the vehicle and adjust tire pressure according to actual weight of the vehicle.

My vote is the sticker/placard attached to the vehicle - unless you change tire size.

 

[bikendan]

Moved thread from the Tech and Repair section to the Forester and Sunseeker sub-forum since the OP is asking for model-specific information.

 

[NoviBill]

One of many tire pressure threads.
This one covers weight vs pressure

Proper Tire Pressure for Michelin Tires
https://www.forestriverforums.com/forums/showthread.php?t=255953

 

[BehindBars]

The tire pressure is specified on the placard on the door jam in all my vehicles. No reason to deviate from that.
-- Chuck

The E-series door placard pressures specified are to accommodate the full GVWR and axle ratings of the motorhome. If running less than those weights, a lower pressure may be desired. My E-450 front axle runs 1000 pounds below FAWR. I never run the full placard specified pressure in my front tires.

I have a 2000 24' Sunseeker with the Ford E450 chasse. What tire pressure do you recomend?

Bill Schneider

To the OP, you can either run the tire pressures shown on the door jamb, or you can choose to weigh the loaded motorhome on a truck scale, consult a chart, and set pressures according to actual motorhome weights. Some people do it one way, some the other. Your choice. Without knowing the weights on YOUR motorhome tires, no one can accurately tell you what pressures to run.

 

[ppine]

I now have a modern truck that measures tire inflation. The difference between summer and winter is more than I thought.

 

[BehindBars]

I now have a modern truck that measures tire inflation. The difference between summer and winter is more than I thought.

There are charts that illustrate the effect of temperature on tire pressure. Speaking of which, autumn in the northern hemisphere is the time to be pumping up tires for the shift to lower ambient temperatures.

 

[NavyLCDR]

And people usually think I am joking about changing summer air to winter air....

 

[kenandterry]

And people usually think I am joking about changing summer air to winter air....

I knew there was something else I forgot when I winterized.

 

[Larry-NC]

You're not kidding!

There are charts that illustrate the effect of temperature on tire pressure. Speaking of which, autumn in the northern hemisphere is the time to be pumping up tires for the shift to lower ambient temperatures.

You're not kidding! We were up in Chicago two weeks ago and a sudden cold snap affected a lot of people. We had a rental car (Ordered a Honda, had to accept a BMW at the same rate because they were out of Hondas) and the tire warnings were driving me crazy. I went to a nearby discount tire store for a filla and there were five cars in line ahead of me.

 

[BehindBars]

We do a winter trip where we may leave home at 20*F and arrive at destination at 70*F. During the course of the trip there, I adjust “cold” tire pressures as needed. Same coming back home but the differential is not quite as extreme in March.

 

[ArcticRam]

YES!

 

[NavyLCDR]

YES!

Great answer!

 

[Tireman9]

There are charts that illustrate the effect of temperature on tire pressure. Speaking of which, autumn in the northern hemisphere is the time to be pumping up tires for the shift to lower ambient temperatures.

As an actual tire design Engineer i do not understand the need for the charts. Tire pressure will change by about 2% for each change in Ambient temperature.



1. Learn your actual load for each axle. (each end of each axle is better as some RV have significant side to side variation but that is a different topic)


2. Using your tire size and your measured load look up the minimum inflation required on the industry standard chart.


3. I suggest you add 10% to that number so you do not have to chase inflation every day as the Ambient temperature changes


4 Set your TPMS low pressure warning level to the pressure in #2 above


5 Set your High pressure warning level to 115% of the pressure in #3 above


6 Your high temperature warning is probably already set to about 158F


7 When traveling in different locations or when Ambient temperature changes by 10F to 15F from the ambient when you set the pressure in #3 you may need to re-center the pressure using your hand gauge as your ref.




You can read my blog if you need more info or background.

 

[Morgan_N]

I strongly agree with sticking with the "cold inflation pressure" on the compliance sticker in the door jamb.

 

[TitanMike]

For those who like to bleed air pressure off in order to prevent the pressure from exceeding the Cold Inflation Pressure for max weight on side of tire be aware of the following.

If you bleed the pressure below the cold inflation pressure specified by the manufacturer for the weight on the tire, you are now driving on an underinflated tire until the pressure eventually builds up enought to support the weight.

During those miles the tire is flexing more than it was designed to wth that weight and tire components will heat up far quicket than the air in the tire chamber.

Driving on an underinflated tire for any distance can lead to unwanted failure in the unpredictable future.

Check the pressure before driving and leave it alone until the next day. Don't try to anticipate any pressure gain.

 

[FastEagle]

"The sum of the maximum load ratings of the tires fitted to an axle shall be not less than the gross axle weight rating (GAWR) of the axle system as specified on the vehicle's certification label.

 

[GnS]

You're not kidding! We were up in Chicago two weeks ago and a sudden cold snap affected a lot of people. We had a rental car (Ordered a Honda, had to accept a BMW at the same rate because they were out of Hondas) and the tire warnings were driving me crazy. I went to a nearby discount tire store for a filla and there were five cars in line ahead of me.

You got lucky, I had the same situation after a cold snap in Dallas area a few weeks ago and took the wife’s car to Discount Tire to let them do it since we were in town. There were about 20 cars in line and it took nearly an hour to get the tires inflated. I would normally do it myself, but the compressor was an hour away back at my home.