Tire pressure

[Skialberts]

Just got our 2017 Forester MBS 2401R. I've seen other posts about tire pressure, but no definitive answer. The tags on the door frame say 61lbs, the tires have 80 lbs on them. Which one is it? We have taken 1 short trip so far and weighed in about 50 lbs overweight. Anything we should be worried about?

[DaveJordan]

Originally Posted by Skialberts

Just got our 2017 Forester MBS 2401R. I've seen other posts about tire pressure, but no definitive answer.

Since there are differing opinions, you won't find a definitive answer.

Lower tire pressures worry some drivers as they're more likely to be driving on under-inflated tires and their fuel mileage may be lower.

Higher tire pressures worry other drivers because the tires may wear prematurely and the ride may be harsher.

All in all, you can run them at 61 psi, at 80 psi, or anywhere in between (I run at 70...). Just don't venture outside of the 61-80 range and you'll be fine.

Dave

[raptor]

I have 2016 Forester MBS 2401R. I put 65 psi in all tires and work great with tire safeguard system that factory set at 65 psi cold setting. Also Les Schwab seems to know that was air pressure to set at too. Yes the sticker at the door said 61 psi. I bought tires monitoring system because I was so concerned. So far after 5 trips 65 seems the set point for my 2401R.

[Mikegjax]

80 psi is the max cold inflation pressure for the tire. It is not a recommened press. It means you won't exceed the design limits if inflated to that number.

[SSmbs]

Was at my sprinter dealer last week. Mechanic urged me to keep at least 70# in tires.

[raptor]

Tire safeguard system set at 57 psi low and 85 psi high. At 60 mile/hour tires pressure went up to between 79 and 80 psi in hot day. I think if they are good in 57 and 85 but considered when they hot and moving.

[SeaDog]

With a motorhome unlike a travel trailer the tire pressure should be varied depending on the weight of the vehicle. 80 psi is the max pressure for the tire to carry max load. there should be a loading chart that gives the tire pressure depending on Gross weight on each axle.

[Mikegjax]

It would not be unusual for tires to exceed 80 PSI if they were could inflated to near that number. Filling to 80 when cold and the expected rise in pressure when operating is all taken into account in design limits.

[MNtraveler]

The RV manufacturer and tire manufacturer work out the inflation requirement based on the tire and the vehicle weight, and that is posted on the door panel. There should never be so much or really any controversy about this. Follow the RV's GVWR of course and if following that then follow the tire inflation posted on the door panel. "Max pressure" stamped on the tire is just that, a maximum, never a guide. All pressures are to cold inflation. Don't change them during the day after driving; the pressures will naturally be higher then.


Land of 10,000 Lakes
2016 Forester MBS 2401R
Nights camped 2016: 29; RV to date: 32

[Skialberts]

Thanks everyone for their input. We will be taking our first extended (3 week) trip in November from Jersey to Florida. We will probably be at max load, so will keep an eye on the pressure.

[Still Kickin]

Originally Posted by Skialberts

Just got our 2017 Forester MBS 2401R. I've seen other posts about tire pressure, but no definitive answer. The tags on the door frame say 61lbs, the tires have 80 lbs on them. Which one is it? We have taken 1 short trip so far and weighed in about 50 lbs overweight. Anything we should be worried about?

In your case the door sticker should not be your guiding reference. Simple rule, knowing you're at max weight limit, run your tire pressure at or very near your tires recommendated inflation pressure. One unkown you are presented with is your individual axle weights, so you will need to monitor tire wear closely until you dial that in. Or, get it weighed (by axle ) when you're typically at loaded weight, and adjust pressures within the tire recommendations accordingly .

[GreenImp]

Originally Posted by DaveJordan

Since there are differing opinions, you won't find a definitive answer.

Lower tire pressures worry some drivers as they're more likely to be driving on under-inflated tires and their fuel mileage may be lower.

Higher tire pressures worry other drivers because the tires may wear prematurely and the ride may be harsher.

All in all, you can run them at 61 psi, at 80 psi, or anywhere in between (I run at 70...). Just don't venture outside of the 61-80 range and you'll be fine.

Dave

I realize the OP has accepted an answer already but I want to say that I have written a few similar responses as Dave's to similar questions as the OP's, but I have never worded it so well as Dave just has.


In my opinion...
+1

[dukeboone]

I run mine at 65psi and the pressure seems to max out at about 80-85psi according to the TPMS with maximum temps so far pushing towards 110.

[ilmor]

When I had my Solera (MBS chassis) according to the sticker the recc. pressure was 65 all around. After researching a little bit, looking at the tire charts, taking into account what the actual weight of the motorhome actually was, w/ cargo and passengers, I determined that 65 was unsafe and ran no less than 73 or 74.

Also consider that my new Sunseeker, similar size to my Solera (shorter, same height, wider) , but with essentially the same tires, recommends 80 rears and 75 front. Then again, it will tow up to 10,000 lbs...

[FFred]

The time to look at tire pressure is after a long hard run at speed.

Look at , just to see if the sidewall max tire pressure is surpassed.

Most tire mfg have a web site that will give initial cold tire pressures for specific tire loading. These take into account the pressure rise with highway travel.

FMCA and other folks can weigh the 4 wheels individually of your RV to find out if there is any overloading.

[DaveJordan]

Originally Posted by FFred

The time to look at tire pressure is after a long hard run at speed.

Look at , just to see if the sidewall max tire pressure is surpassed.

Well...no.

As explained at tirerack.com, here:

Tire Tech Information - Tire Specs Explained: Maximum Inflation Pressure

the maximum pressure rating for a tire is the maximum cold pressure. Tires are designed to handle hot, in use, pressures considerably higher than the rated pressure embossed on the side of the tire.

Dave

[GreenImp]

Yes, tire pressures should always be set COLD. In fact many tires even use the word cold right on the sidewall rating.

[Airdale]

Originally Posted by Skialberts

Just got our 2017 Forester MBS 2401R. I've seen other posts about tire pressure, but no definitive answer. The tags on the door frame say 61lbs, the tires have 80 lbs on them. Which one is it? We have taken 1 short trip so far and weighed in about 50 lbs overweight. Anything we should be worried about?

The correct pressure is 61 PSI cold. Never use less than that. If you have to go higher you're probably over weight.

The tire pressure indicated on the tire sidewall is the maximum permissible by it's manufacturer for that tire whatever size or brand.

[GA_Boy]

I don't care what air pressure the door sticker says. I set air pressure COLD according to my gross weight and tire rating.
I suspect that in Skielberts case the 61# may have been MAX for a smaller tire.
It could also be based on the vehicle gross weight and the current tire (Less load range).
Marvin

[Airdale]

Originally Posted by GA_Boy

I don't care what air pressure the door sticker says. I set air pressure COLD according to my gross weight and tire rating.
I suspect that in Skielberts case the 61# may have been MAX for a smaller tire.
It could also be based on the vehicle gross weight and the current tire (Less load range).
Marvin

The safety standard you follow is from the trucking industry safety standards found in FMCSA regulations. They do not require a recommended cold inflation pressure. Their minimum is based on load carried. That standard does not provide any load capacity reserves whatsoever. It is also not in compliance with the FMVSS standards our RV trailers and almost all of the vehicles used to tow them were built to follow.

Motorized RVs are built to the standards found in FMVSS regulations.