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I've only had my vehicle for two months or so. I haven't been in my vehicle for a week and a half. Covid, working from home, etc. And it's gotten a bit colder. Tires are Michelin Primacy MXM4M 19"'
Today warning light came on. 3 tires at 37 psi, one at 38 psi. It didn't like the 37 but in warn weather it was not unusual to start at 37 and go up to 40. Do you follow the sticker on the door or the sticker by the gas cap?
The warning is based on the pressures that were last set as reference. Given you only had the car for two months, unless you adjusted the pressures and then set them as the reference yourself, there's no telling what the reference pressures currently are. Adjust them according to the the gas cap and then reset TPMS.
Yes, set the cold pressure on all four tires to your desired level, then go into the service menu and reset the reference pressure. The system will then compare the TPMS results to the reset reference numbers and the warnings will go away ... for a whlie.
anyone know of a way to get the tire pressure scene to "come up" so it is easy to see what the car thinks the pressures are ?
As shown above, for the regular MB models as far as I know it's only found under the service menu. AMGs should have a separate display as shown below, that shows all the powertrain and tire temps along with the tire pressures. It's pretty much one of the standard displays I have up at all times and so far has resulted in detecting two punctures shortly after pulling out of my garage and noticing that the tire pressure in one tire is lower than it should be.
I should have written down the "original" tire pressure when I picked up my vehicle. I want to say it was 40/41 warm.
This morning, cold tire pressure was 35 front & rear. Then went up to 37 front and 38 rear warm.
I'm trying to decide if I want to set it back to higher? I think I do. Gas cap label says 38 max front and 39 max rear, COLD. Maybe set it to 41 front and 42 rear? Does it really matter if I am 1-2 psi over the MAXIMUM? By the time I get to my tire shop my tires have warmed up a bit.
Sorry if this is a basic question. I haven't had run flats before so I'm trying to figure out what is best for them.
Don’t set it back higher, it rides MUCH Better at lower pressures.
Mercedes recommends a pressure, worst case just use that and it’s 35.
That’s 35 cold yes, so warm might be 39? So 35 cold would be your target yes? Can you let it go below that? I did get the feeling that 40 plus was a bit high.
That’s 35 cold yes, so warm might be 39? So 35 cold would be your target yes? Can you let it go below that? I did get the feeling that 40 plus was a bit high.
Don't worry about warm, the pressures are set cold. Whatever pressure they are warm is whatever they are.
Same as yours AMG 19s, I had Michelin Primacy non runflat and now have Pirelli PZero non runflat, runflat vs non runflat makes no difference for pressures.
Same as yours AMG 19s, I had Michelin Primacy non runflat and now have Pirelli PZero non runflat, runflat vs non runflat makes no difference for pressures.
Don't worry about warm, the pressures are set cold. Whatever pressure they are warm is whatever they are.
I run mine at 31 cold.
Suggestion, set cold in the early AM before Sun hits the car. If you park outside, depending on sun location it may heat up 2 tires on the sunny side. This will affect tire pressure by 2 to 3 lbs. If you're in a garage, your good to go.
If you have a Costco nearby you can use their system which enables you to pick exactly the pressure you want and then it stops automatically when you hit it. I have the Primacy MXM 19" and I have done this twice in 3 years to get all the tires back to exactly where they need to be.
If you have a Costco nearby you can use their system which enables you to pick exactly the pressure you want and then it stops automatically when you hit it. I have the Primacy MXM 19" and I have done this twice in 3 years to get all the tires back to exactly where they need to be.
Just get yourself this little compressor for your garage that does the same thing, works great:
I have a Ryobi 18+ compressor in the garage that I use most often, and the kids use it to inflate soccer ***** etc..
I also bought a Slime - Flat Tire Repair Kit - Digital that I threw in the trunk, I figure that if I get a flat on the run flats while on a road trip, this may get me going again without having to rush to a tire shop, I also bought a tire plug set. But truth be told, I don't remember the last time I got a flat (famous last words!)
We run all our MB's at 40 PSI. Easy to remember, helps with fuel economy, extends tread life & you're good up to 165 MPH or so They may run a tad bit rougher if your roads are really bad (?) but most of our cars have air suspension to help smooth things out.
IMO, the car rides like a completely different car at a pressure like that...I bought the car for it to have an excellent ride, and if that means I have to buy tires more often so be it. If I cared about fuel economy and tire cost I wouldnt be driving this lol
10-03-2022, 10:22 AM
They may run a tad bit rougher if your roads are really bad (?) but most of our cars have air suspension to help smooth things out.
