I recently had my 20" Sport Techno rims for my CTTS professionally refinished, and as an additional "refresh" decided to install all new TPM sensors and tires (which were needed anyway). I went with Oro-tek OBE-005's, which is the spec'd sensor for the CTTS by Oro-tek. Being totally **** about all things wheels & tires related, I also tracked down a tire pressure gauge that is fully compliant with the California "Regulation for Under Inflated Vehicle Tires" as to accuracy.

Here's the rub. I set cold, partial load inflation pressures (38F, 43R) using my certified accurate tire gauge. I set the vehicle's TPMS set-up to summer tires, partial load, etc. I mounted Porsche N spec Bridgestones on my refinsihed wheels (awesome tires, BTW!!!). But either the wheel sensors are sending inaccurate date or the vehicle's TPMS control unit receiver is providing inaccurate readings to the dash display. Both front tires are reading 2 psi high when cold (i.e., 40, when the tire gauge says 38), and the rears read 1 psi high when cold (44 psi instead of 43 psi shown on the tire gauge).

I know it's not a big deal, but I'm wondering if the non-OE TPMS's are just inaccurate or not, or if these types of variances also occur with the OE Beru sensors? The only concern is that if the vehicle's system is displaying optimistically high values, then the tire pressures could actually be lower and the vehicle wouldn't "warn" me even though it should.

Anyone else ever compared gauge readings versus the TPMS readings?

 

My OE Beru sensors have always been spot-on with my several of my tire gauges (and I do not use the cheap gas station gauges). The Beru sensors are used on some of the fastest cars on the road (Veyron, Porsche, Bentley, Mercedes, etc) , so I imagine there would be liability issues if there were not tight tolerances on reporting values.

 

my replacement Beru sensors also read spot on.

 

I check the TPMS pressures also with a guage and it is always been spot on.

 

I have four different tire pressure gauges and they all read somewhat differently. I am now convinced that the one that is supposedly accurate for the California tire pressure regulations standard reads high. My other gauges all gave me different readings, and all were 1 to 2 psi lower, and more consistent with what the in-vehicle TPMS display was showing. The real value of a TPMS is to let you know if one of your tires has lost a significant amount of pressure, causing a potential safety issue. Their accuracy, within a few psi, is no big deal.

 

I'm in need of replacement TPMS also for my 06 Cayenne Turbo S. Mind if I ask where you guys are purchasing yours?

Thanks,

Walt

 

If you check your tire pressures using both a traditional tire guage and using the vehicle's sensor system, then you can probably make do with less expensive TPMS sensors. The Berus are at the expensive end of the scale, but they're likely the best and that's why they are used as OE.

If you're a bit more budget minded, then I've found that the Oro-tek OBE-005 sensors do just fine. I don't have any experience yet on how long their batteries will last compared to the Berus, though. I found a set for $46 each on eBay, probably about a third of the cost of the Beru sensors.

 

I bought mine at TireRack the are Beru TPMS.