[masraum]

Originally Posted by Por_sha911

I have had this gauge for decades. There are other gauges 5 times the price but I don't need one for science or pro racing purposes. The cheap pencil ones can vary 5-6 pounds and are worthless. The tire store gives them away and I tested 4 of them and each one was different from my accu-gage (some by quite a lot).

That's been my experience and why I have 3 of the AG dial gauges. They seem to work very well.

Everything I read says that the smaller the pressure spread 0-60 versus 0-120 psi will give you a more accurate reading.

Sure, which is the same reason that I prefer analog gauges in the dash that span 270º vs gauges that span 90º, better resolution.

As far as accuracy is concerned, each gauge may vary by a pound or two but if you use the same gauge you will know whether the pressure is going up or down (hey, temperature of the air and cold tires versus just driven will cause a variance of a few pounds).

The rears on the boxster can change 6-7 psi on a single drive due to heat. The fronts usually only gain 4-5 psi.

And if the weather in the morning is in the 30s but the afternoon is in the 60s or 70s, the difference from cold tires in the morning to hot tires in the afternoon can be 10-15psi.