Originally Posted By: crazyoildude
I have 3 tire pressure guages and they all show different readings on the same tire, even the one i have at my shop built into the air hose which is under a year old says something different...The reading are from 4 pounds to around 10!
I know the Stealership i deal with must be way off because they pump them way up on new cars i guess to squeeze the best gas mileage out of the new car of course that makes the ride rock hard!
Who knows where i can get an accurate tire pressure gauge???
I know many think theirs are good but how many of you tested it against some others?
Dealerships pump up the tires more than specified because they don't know exactly how long a car will sit before it is bought, and will certainly be below spec after sitting on the lot if they inflated them to exact when first put on the lot. It's also a well known fact that underinflation is what causes most tire failures, and would rather sell someone a car with a few extra psi than a few less psi. Car buyer's usually don't check their tires often in the first place, and so the extra PSI is a cushion for quite a few variables. Unfortunately some cheap dealerships don't care and just put the car on the lot without checking the tires. Sad really.
The most accurate types are the oil filled dial types, and digital types, but you will be paying more than usual for a dial gauge.
Pencil types are the least accurate because they rely on the resistance of the stick to stop the gauge and show pressure. depending on how loose or tight this stick is can vary the reading quite a bit, as well as gravity. you sometimes can get two different readings on a pencil type that's loose by holding it upright for one reading and upside down for another because of gravity.
Good for when you have nothing else, but a dial type is definitely more accurate. Digital has the least moving parts, and then using electronics calculates the Pressure, not by some numbers painted on a face with a stick or needle.
Digital is my bet, but those expensive 40 dollar oil filled dials are pretty accurate as well. Go to a racetrack and see what they use. Accuracy is crucial to them, and they spend a pretty penny on pressure gauges. They'd be the best source for tire gauges.
