Tire pressure question...help.

hts128i · 08-10-2008, 11:46 PM

I've had my 128i base coupe (with 17 inch wheels x 4) for a couple of months now and just checked the tire pressures for the first time today. The pressures were 29 all around. The owners manual and the door placard recommend that the front tires be inflated to 32psi and the rear tires be inflated to 35psi. If the tire sizes are the same all the way around the car why would BMW want the tire pressures higher in the rear than in front? Is this safe? Thanks for your help!

emm3tt · 08-11-2008, 01:16 AM

Tire pressures play a big part in handling and ride quality. Think of your tire pressures as a secondary "spring."

mikeo · 08-11-2008, 05:17 AM

29lbs is too low for sure and will cause faster tire wear and less fuel economy. BMW always recommends higher rear tire pressure vs. front to promote understeer. Set the pressure cold (before driving) at 34 F and 34 R for awhile then change front or rear in 1lb increments to feel the effect.

08-10-2008, 11:46 PM	#1
hts128i Enlisted Member 1 Rep 33 Posts Drives: '08 128i - 2009 TiAg 135i soon Join Date: Jun 2008 Location: Huntington, WV iTrader: (0)	Tire pressure question...help. I've had my 128i base coupe (with 17 inch wheels x 4) for a couple of months now and just checked the tire pressures for the first time today. The pressures were 29 all around. The owners manual and the door placard recommend that the front tires be inflated to 32psi and the rear tires be inflated to 35psi. If the tire sizes are the same all the way around the car why would BMW want the tire pressures higher in the rear than in front? Is this safe? Thanks for your help!
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08-11-2008, 01:16 AM	#2
emm3tt Out Driving 29 Rep 685 Posts Drives: Join Date: Jun 2007 iTrader: (1)	Tire pressures play a big part in handling and ride quality. Think of your tire pressures as a secondary "spring." __________________ Emmett 01 E46 M3
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08-11-2008, 05:17 AM	#3
mikeo Santa Fe Concorso 103 Rep 2,984 Posts Drives: '11 M-sport 328i, '13 X1 28i Join Date: Jul 2007 Location: Santa Fe, NM iTrader: (3)	29lbs is too low for sure and will cause faster tire wear and less fuel economy. BMW always recommends higher rear tire pressure vs. front to promote understeer. Set the pressure cold (before driving) at 34 F and 34 R for awhile then change front or rear in 1lb increments to feel the effect. __________________ Santa Fe Concorso - The Southwest's Premier Automotive Gathering.
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