Is the TPMS accurate
 

2008 6sp. I checked the tire pressure cold on the DIC and all were 28 psi. I then checked them using my Harley gauge and a BMW digital and they both registered 31-31.5 psi. Could the DIC be off and should I add a couple of pounds to bring them all up to 30. Thanks

My DIC reading is usually within 1 psi of my tire guage.

Check out THIS thread on the topic...especially the last post. :yesnod:

Usually, my car readings are also w/in 1-2 psi of all my handheld gauges. If ALL your tires individually read 3+ difference fr. your handheld gauges, I'd say something is wrong. Which one is wrong---the handhelds or the car's---I can't tell you. But my bet is on the two handhelds. I've tried about 4 old style pencil gauges and two different digital ones, and the difference was very small.

I have never found the tire pressure sensors in my C6 or my previous C5 to be all that accurate. They aren't even consistent either, I'll set all four tires at 30psi and then immediately check what my DIC reports and it will often report all the tires at different pressures (some off by 3 or 4 psi) And then a few minutes later all four will read exactly the same. This is with OEM sensors too (I know that aftermarket ones are even worse!)

I mostly just use the system to let me know when one tire is going flat, and even then you can't trust it 100% as I have one sensor right now which often gives a 0psi reading for a few minutes then two minutes later it reads 30psi, then a few minutes after that it's telling me 40psi! I'm sure the battery in it is dying, I plan on replacing that sensor real soon.

I agree with this. All 3 Vettes (98-05-07) I have had were about 1 degree lower than a a CERTIFIED gauge used to check. Thats good enough for me.:D

It's not the accuracy that's important. What is important is to know if there is a significant difference on the downside in one or more tires. If they all read 28, 30, 32, or whatever and one drops several pounds lower than the rest, you'll know there is a problem.

At one point I checked 7 gauges and found a 5# variation. I don't get my gauges certified, so I simply threw away the ones at the extremes. Maybe the 4 remaining are all off from perfect, but my tires won't notice the difference.

Same here

I too think the gauges are the most inaccurate. But as someone said, having them all at the same pressure is a good goal, even if it varies off the recommended 30 psi a bit.

I only rely on my digital which reads in tenths. And I know it's
more accurate, because it produces repeatable performance.

Compare that to the DIC which reads in much larger 1 psi increments.
TIPS is really only there to warn against catastrophic failure.

For the casual driver it's probably good enough to set your tires by.
But if you drive a Corvette, chances are you expect more than tires set within 1-2 psi of each of other. So buy yourself a good tire guage if you haven't already.

The purpose of the TPMS system is to show the driver a loss of air pressure...it is not for the purpose of inflating tires accurately. Use a good handheld gauge for this.:thumbs:

The sensors are as accurate as any other non calibrated gauge. If you want an accurate measurement of your pressure get 10 gauges and average the readings.

Bill

Mine is always 1 PSI less than a regular tire gauge.