Cold tire pressure on FR Forester

[Papa Dee]

Please advise me on cold tire pressure for my 2018 Mercedes FR Forester MBS. Just had a rotation and shop left the tire pressure at 75 lb. I think this may be a little high.

Thanks
Papa Dee

[Homebrew]

Cold tire pressure is listed on the tire, some are listed on a sticker in the door jam.

[DaveJordan]

There have been lots of discussions about tire pressure, you can search the forum. Personally, I'd go about 70 - it's higher than required, but provides a little extra security (for me)

[Chuck_S]

Cold tire pressure is listed on a placard in the driver's door jam. Maximum tire pressure -- which is just that -- is on the tire sidewall and is way too high for passenger car tires. Maybe for trailer tires but not for a motor vehicle.

-- Chuck

[BehindBars]

There was a recent discussion about MBS tire pressures, but it was kept over in the Dynamax forum rather than moved to the Mercedes-Benz Sprinter forum. Perhaps it could be of some help: https://www.forestriverforums.com/fo...on-259265.html

I believe most MBS motorhomes run near full GVWR, so the ISATA 3 (discussed in the other thread) and MBS Forester could be near the same loaded weight. Weighing your loaded unit on a truck scale is the proper place to begin for determining ideal tire pressures. In the absence of known actual weight, go with the pressure recommendation on the driver’s door jamb placard.

[BehindBars]

Originally Posted by Chuck_S

Cold tire pressure is listed on a placard in the driver's door jam. Maximum tire pressure -- which is just that -- is on the tire sidewall and is way too high for passenger car tires. Maybe for trailer tires but not for a motor vehicle.

-- Chuck

I think you are wrong to say sidewall maximum pressure is way too high for a motor vehicle. The MBS motorhome (a motor vehicle) rides on Light Truck tires, not passenger car tires. Depending on the RV weight, ideal pressures for class Cs do in some cases run near the tire sidewall maximum rating.

As an example, and while not an MBS chassis, my class C Ford E-450 chassis requires, per tire load chart, just shy of 80 PSI (the sidewall rating) on the rear duallies to carry the axle rated 9600 pounds. The door placard recommends the same pressure as the sidewall maximum for the rear tires.

I think your post is possibly misinforming the OP.

[mlmay12]

Originally Posted by Papa Dee

Please advise me on cold tire pressure for my 2018 Mercedes FR Forester MBS. Just had a rotation and shop left the tire pressure at 75 lb. I think this may be a little high.

Thanks
Papa Dee

Without a ton of discussion. Mine is listed at 61 PSI Cold and thats what I run it at. It is always at GVW which is the same as yours at 11,030 lbs.

[aircommuter]

There are many variables and considerations. Where I live in the mountains I must go on a windy road that has a rough slurry coat at least 20 miles in any direction. If I try to run below max sidewall pressure the outsides will wear rapidly. That’s from a VW beetle through a 3500 with a camper. Other considerations are lower pressure means more sidewall flex and more heat. Less pressure means poorer handling and mileage.
Many truck fleets run pressures 5-10 psi over sidewall listed pressure. You must evaluate what works best with your situation but always stay at or above a pressure that that is needed to properly support the weight as needed.

[Papa Dee]

Alot of good usable info. Something to study & ponder. Thanks.

Papa Dee

[NavyLCDR]

If running the tires at the maximum sidewall pressure were better for the vehicle, than what purpose would be served by the manufacturer specifying a lower pressure for the tires?