2008 Mercedes-Benz C300 Sport: Gauge Match
December 22, 2008
Over the weekend, our long-term Mercedes C300 threw up a low tire pressure warning. It's one of those systems that tells you that you have a low tire, but not which one, so you have to check all four tires to see which one's low.
I finally got around to checking the pressures right before this morning's commute. Factory pressures listed on the doorjamb are 33 psi front and 38 psi rear.
The fronts, according to my handheld digi-gauge, were 31.5 and 32 psi, and the rears were 40.5 and 35 psi. None of those measured pressures come even close the accepted TPMS threshold of 25%. Curious, I re-checked a front tire several times with the same gauge: 26 psi. 17. 34. 36. 32.
So, yeah, time to get a good tire pressure gauge.
Jason Kavanagh, Engineering Editor @ 19,697 miles.