Over the years, I've had a series of 12V tire pumps that ranged from bad to worst. Usually bought at the local Harbor Freight, Walmart, or auto parts store, they don't come close to this one: long air hose - nearly twice the length of the others, you don't worry about it hanging from the tire filler valve. quick release connector - instead of trying to screw and unscrew difficult, leaky valve connectors, the quick release lever means you don't loose air pressure while removing. long 12V power plug wire - easily reaches the wheels from the car 12V plug. accurate easy autoshut off - the easiest to program units and pressure, it easily fills the tire while you can do other things (like dispose of car debris.) It might have trouble with inflating four truck tires, this is for consumer grade cars. But in light duty work, it worked great. Taking advantage of an Amazon sale, the $21 was more affordable than any I've bought before. Bob Wilson
Funny I just got this one online. Double the price but its great. Has a flash light, 6000mah power bank and also a glass breaker attachment that was not in the discription online. Having it cordless is pretty cool versus the traditional ways. I wanted a digital inflator for better accuracy to test out my new tire pressure monitoring system.
Do you have a known-accurate gauge around to check how accurate this digital gauge is? A digital display with a decimal place doesn't have to say much about how close the reading really is. I remember my old Mazda 323 had different trims with a conventional or a digital speedometer, and the specs for both were in the repair manual, and the conventional one had closer tolerances. They allowed the digital one to be off by as much as 15%. That'd be like 9 MPH at 60. But hey, it had digits.
I prefer and use this one from Ryobi. There's no need to plug it in and drain the 12 volt. RYOBI ONE+ 18V Cordless High Pressure Inflator with Digital Gauge P737D - The Home Depot
Actually, I have a 12 V "jump box" with a 12 V accessory outlet. On the road, I prefer the vehicle 12 V system that includes a traction battery-to-12 V converter. For a trailer, the "jump box" works just fine. Bob Wilson
Got a 12 volt that has held up the few times I needed it. For 'day to day' use, it is one that plugs into a wall outlet. Don't have to turn on the car, or drain its battery. Battery would be more convenient, but what was available when I got the above were mostly lead-acid models. Their convenience needs to be balanced against the battery cost, and eventual replacement.
