William D. writes by email: “How do you know if your tire pressure gauge is accurate? I have a stick tire pressure gauge (the kind shaped like a pencil where a stick pops out of the bottom to indicate the pressure) that I’ve had for decades and worked fine (or so I believed) until I got a car with the tire pressure sensors. The problem is the car’s sensors and the stick gauge disagree by 3 to 4 lbs. So I bought a dial gauge, hoping it would prove one or the other correct. Nope, that one is off 3 to 4 lbs. in the other direction. Are the sensors that come with modern cars (mine is an Altima) accurate? Are sticks better than dial gauges?”
Thanks for writing. I suggest you use a digital tire pressure gauge. Stick or “pencil-type” gauges are not very accurate and while dial gauges are usually better, digital can show pressure within 0.1 PSI, allowing the user to get all of the tires equally inflated.
Digital tire pressure gauges are now relatively inexpensive and easier to use than other types you mentioned. The tire pressure sensors are relatively accurate as they have to adhere to Federal law and trigger the TPMS warning light when the pressure drops 8 PSI below the door placard pressure.