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Tire pressure with electronic gauges - Overdoing it?

I bought a 2010 Chevy Silverado back in April of 2010, and began monitoring my tire pressure with the on-dash electronic gauge. I’ve noticed that, while the manual says that 35 psi is where I should keep my tires, they fluctuate a lot, hardly ever OVER 35, but oftentimes below (down to 31 when it’s cold). What should I do? Inflate in warm weather to 37-38, stay where I’m at, or try to “ignore” my tire monitor? Thanks!

Also, I live in North Texas, so winters are typically 30-65 degrees, rest of the year 60-110.

The manual is referring to what the COLD pressure should be. That means when you check and fill them do not drive to the gas station, do not go to the parts store for a new gauge, do not pass go or collect $200… lol.

Seriously though if when you start it in the morning it reads 31 psi then they are a little low (assuming they should be at 35) and should be filled a little more. The pressure after you have been driving for a while should be ignored unless it’s getting lower. I.E. You are getting a flat.

Hoper this clears it up,

Thanks Carve, that makes sense. I look at them and they feel like they look flat. If what you say is true, I’ve been driving them flat for pretty much as long as I’ve owned it. :frowning:


Radials always look a little flat. Go by pressure. You are suffering from too much information, and I wouldn’t be worried about it. Buy a gauge for about $8 and compare the measurements with your new gauge and the Chevy TPM system. Do it first thing in the morning beofre you move the truck. Then you have a comparison to see how much, if any, the TPM system is off.

We have a car with the tire pressure monitoring system. I have topped up the tire pressures and then have seen what the TPMS says for each tire. Consider the system to be a rough indicator of your tire pressures, not quite good enough to use in place of a quality tire pressure gauge.

The changes in tire pressures that you are seeing under different ambient temperatures and with tire warmup due to driving are to be expected.

Set your tire pressures cold with a quality ($15 or so) or known good pressure gauge. The very best you can do is to set the tire pressures before driving each day which is more than almost anyone would care to do. If the outdoor temperature is on a upward or downward trend, then check and adjust periodically. Every two weeks should be sufficient but I will not admit to doing that.

Thanks jtsanders. They are stock radial, General Grabber’s P245 LT70 R17’s. I’ll get a gauge and compare measurements. My main issue was the amount of fluctuation, mainly below what I expected.

Thanks Wha Who, I’ve wondered how much driving was affecting the readings. I figure I’d give it two months (maybe three) to balance the readings out, then try to maintain a rolling two-month average, just was unsure since the readings seemed to be all over the place, considering where the manual said they should be.