Which would you trust?
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 760
Likes: 1
From: N.W. Arkansas
Which would you trust?
Ok,, so im checking the tire pressure on my new 08' weekly with the TPMS and thought i would check it against a digital tire gauge which is right on the money with two other ones i have and also my Avalances TPMS..The vette shows 28psi (TPMS) and the digital gauge shows 30psi,,, which would you trust? ,, all tests done on cold tires.. later rj
CF Community Team
Joined: Nov 2005
Posts: 5,262
Likes: 2,893
From: Charlotte N.C.
Either, however most digital gages I have have 0.1psi resolution. I have seen everything from spot on to 0.5 psi off of advertised super accurate gages. I've seen older pencil gages that are 5 or more psi off, there's a special storage place I have for them.
Since you have a few in consensus it appears the vette tpms is off but you can't say for sure.
Since you have a few in consensus it appears the vette tpms is off but you can't say for sure.
CF Senior Member
Joined: Feb 2006
Posts: 23,313
Likes: 25
From: Tucson Arizona
Remember that The TPM sensors transmit tire pressure readings once every 60 seconds while the vehicle is being driven and once every 60 minutes when the vehicle is stationary for more than 15 minutes. Even having one side of your car in the sun (the other side in the shade) can affect readings. If your digital gauge differs from your on-board readings but coincides with three other measures, I'd rely on the digital gauge.
Not all gauges are IMO created equally. I found Craftsman has a decent digital gauge for about $35.00 guaranteed accurate to a 1% variance. You might even compare readings from your digital gauge to a gauge deemed reliable at a tire store.
You can go nuts with different gauges giving different readings. Buy a quality gauge and rely on it.
Not all gauges are IMO created equally. I found Craftsman has a decent digital gauge for about $35.00 guaranteed accurate to a 1% variance. You might even compare readings from your digital gauge to a gauge deemed reliable at a tire store.
You can go nuts with different gauges giving different readings. Buy a quality gauge and rely on it.
CF Community Team
Joined: Nov 2005
Posts: 5,262
Likes: 2,893
From: Charlotte N.C.
I went to Sears.com and the best resolution digital is 0.5psi and none have an actual accuracy on them... If you have one that does say 1% it would probably be of the range so 1% of 100psi would be +/- 1psi. If its a 199psi gage it would be +/- 2psi.
When you work calibration you find out the world is very inaccurate.
When you work calibration you find out the world is very inaccurate.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
I have checked the TPMS against several gauges and there is a consistent 2 psi difference when tires are cold with the gauges reading 30 psi. I trust my gauge and use it to calibrate the DIC reading. If DIC says 28, I'm good to go.
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 465
From: Southern Utah
I have a couple from these guys:
http://www.ghmeiser.com/dial.htm
Le Mans Master
Joined: Jul 2005
Posts: 6,350
Likes: 273
From: Hoschton Georgia
I agree, use a good dial gauge (round and high quality) and then use the TPMS to monitor changes in tire pressure.
I have a couple from these guys:
http://www.ghmeiser.com/dial.htm
I have a couple from these guys:
http://www.ghmeiser.com/dial.htm
Race Director
Joined: Oct 2004
Posts: 10,089
Likes: 14
The number molded into the tire sidewall is the DO NOT EXCEED absolute maximum pressure. Don't ever inflate your tires this much. The placard on the driver's door is the one you follow since it is calculated for the vehicle weight. It says 30 PSI cold. Do not exceed.
Race Director
Joined: Jun 2005
Posts: 10,909
Likes: 2,701
From: Phila Suburbs 2023 C8 & 2013 650ix
The pressure on the tire is not the absolute maximum tire pressure it's the maximum cold tire pressure. (ie 44 psi) Didn't we clear that up a long time ago? If you want to compare gage pressure to the TPMS do it right after you shut the car down. If you wait the car will remember the pressure when it was shut down and the tire will cool and the pressure will go down 2 or 3 lbs.
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 26
From: Austin Texas
I've had three different sets of TPMS in 3 sets of wheels on two cars. Every set has been aprx. 2 psi low compared to many different gauges. I inflate to and maintain 28 psi per the DIC and am convinced I've got 30 psi in the tires.
Le Mans Master
Joined: Feb 2007
Posts: 8,514
Likes: 235
From: Currently somewhere in IL,IN,KY,TN,MO,AR,MS,AL, or FL
I bought a nice digital gauge and it seemed to agree with the TPMS for the first few months. Then it started reading lower. It now reads 5PSI below the TPMS on the first reading but if you keep taking readings it slowly comes up in pressure. I still trust my 40 year old analog gauge more than either because I know it is off 2 pounds at 32.
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
first off, good for you for checking your tire pressures so often. second, I agree that an aftermarket gauge will be more accurate sometimes. Not always, but sometimes. I probably have 7 or more "old-style" gauges, at least 4 of which give the same reading on different tires. They also agree with my digital gauge.
I'd trust these five...
I'd trust these five...