Tire Pressure
01-19-2008, 08:58 AM
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BMW 335 Conv.; MB GL 320CDI
Tire Pressure
The sticker on the door panel of the 320 GL states 32 psi in front and rear tires under normal conditions, with 38 psi on the rears if the car is loaded. The dealer put 35 on all four tires (registered in cold weather-tires register 37.5 in warm garage.) at delivery, but if anything, the tires look a bit soft to my eye. I will say that I am not used to SUV tires so it might be just be me; last car had low profiles which I kept at 40 psi.
01-19-2008, 11:44 AM
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GL450 (Alabaster White/Black Interior)
I personally run all of my tires at two pounds over the loaded specs (i.e. 34 in the front and 40 in the back). I go two pounds over to allow for air leakage and what not. I agree with you in the front tires looking soft at 34/35 psi.
01-19-2008, 05:21 PM
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2004 RX330, 2008 Scion xB, 2001 Honda Insight Hybrid, 2010 Toyot Prius v ATP
I had a TMPS (well, equivalent) warning last night and this morning again on my way for coffee. Visual inspection last night and before taking off this morning made me reset the system but the warning came back, so when I got back with the coffee I hooked up the compressor - driver's rear was down to about 25 psi but it looked perfectly normal to me. Okay, I don't have the youngest eyes but for pressure that much lower (everyone else is at about 33/34) it should've been noticeable. I think they just always look a little soft.
Now, if I'm doing highway driving I add at least to the back if not both front and back, my feeling being that more air allows greater heat resistance. Am I wrong to do so? (Let the soap boxing begin!)
Now, if I'm doing highway driving I add at least to the back if not both front and back, my feeling being that more air allows greater heat resistance. Am I wrong to do so? (Let the soap boxing begin!)
01-19-2008, 07:12 PM
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GL450 (Alabaster White/Black Interior)
STP, I believe you are correct. I have always been told that low air pressure will significantly heat up the tires and potentially cause failure.....
01-21-2008, 12:26 PM
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'06 A6 & '08 GL550
Perfect Timing
The warning light on our 550 came on Friday too. Took the cold tire reading and all 4 were within 1 psi between 32 and 33. Looks like I need to head to the filling station soon.
01-23-2008, 12:29 AM
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'06 A6 & '08 GL550
What are 550 owners running your tire pressure at?
When I filled ours up with air today, I noticed that the recommended pressure for the fronts were 35psi and the rears were 42psi. I filled them all the way up, so you can imagine the time it took since mine were in the 32-33 range.
When I filled ours up with air today, I noticed that the recommended pressure for the fronts were 35psi and the rears were 42psi. I filled them all the way up, so you can imagine the time it took since mine were in the 32-33 range.
