The wrong amount of air in your tires affects more than just your rubber: It alters ride quality, can lower your fuel economy and can even cause an accident.
Tire gauges measure the amount of air pressure in your tires in pounds per square inch, or psi. When shopping around, you'll find three main types: pencil or stick gauges are the cheap, small gauges commonly found at gas stations and checkout lines. Dial gauges display the psi reading on a large, round face and often connect to the valve stem with a flexible hose -- handy for hard-to-reach valve stems. Digital gauges are battery operated, and generally are about the size of a cell phone.
Determining the best digital tire gauge is simple because so many people rave about the Accutire MS-4021B Standard Digital Tire Gauge (*Est. $10) . Popular Mechanics calls it a "must-have car gadget" and recommends it because it is "as accurate as much higher-priced models." At about $10, this digital gauge costs little more than a junky stick gauge, and it is far more precise and reliable.
The Accutire digital gauge's large red characters show tire pressure in half-pound increments so clearly that Car and Driver says "its ease of operation won't leave anyone misinterpreting its measurements." It is a top pick by a respected consumer testing organization, and it stands out with one of the largest readable pressure ranges in that organization's test group. The MS-4021B can measure tire pressure from 5 to 150 psi.
The Accutire MS-4021B Standard Digital Tire Gauge is also popular with consumers. For more than six years, it has been one of the Top 100 automotive bestsellers on Amazon.com and is the retailer's most popular tire gauge, period. Most users posting reviews say that the Accutire gauge makes a tight seal on a tire's valve stem and doesn't leak air. "This is by far the best tire gauge I've ever had," writes one customer who posted a review.
Also popular on Amazon.com is the Accutire MS-4350B digital tire gauge (Est. $15) . Most reviewers at Amazon.com like its bright blue display and say the tire gauge is easy to use. It includes a programmable feature that stores the recommended tire pressure for front and rear tires; in reviews, some users say that they like this bonus, while others didn't use it.
An alternative to a battery-operated digital tire gauge is an analog tire gauge. A dial-style tire gauge typically connects to the valve stem using a short length of hose, reading tire pressure on a handheld round face. Because you need two hands to operate one, dial-type gauges take a little more dexterity to use. They tend to cost more than a digital gauge, and higher-priced gauges are often more precise and feature-packed. They're also a good choice for motorcycle owners because the hose lets you better reach the valve stems.
The Joes Racing 32307 Tire Pressure Gauge (*Est. $30) gets outstanding reviewer feedback from Amazon.com users, who rate it a near-perfect 4.8 out of 5 stars overall. "There's a reason this has an almost solid block of five stars -- it is a very well made, high quality, accurate tire pressure gauge," writes one customer.
The Joes Racing tire pressure gauge features a large dial face that glows in the dark, and it has a 17-inch-long hose. It also offers the convenience of a ball and an angled chuck (users can switch between the two) that attaches to the tire's valve stem. Several motorcycle riders posting reviews on Amazon.com say the Joes Racing gauge works well with their motorcycle tires, where spaces are often cramped and awkward to access. It measures between 0 and 60 psi, and it is best used for tires kept around 30 psi (this is in line with the recommended tire inflation pressures of most passenger cars).
For one Amazon.com user, the choice was between the Joes Racing 32307 Tire Pressure Gauge and the more expensive Moroso 89560 Tire Pressure Gauge (Est. $40) . Car and Driver features the Moroso 89560 as one of its top five tire gauges, calling it "about the least-expensive racing gauge on the market." Standout features that they mention include the "angled nozzle with swivel chuck."
Moroso's 89560 tire gauge has a 4-star average overall rating at Amazon.com. "Nice gauge, but wish some aspects of it were of better quality," says one review. This observation sums up the views of many users: This gauge seems to be accurate, but some find the hose to be a little stiff , and others question its durability. Both Amazon.com users and Car and Driver recommend purchasing a separate cover to protect the gauge.
Gas stations and checkout lines seem to offer an endless supply of inexpensive pencil-style tire gauges. Though purchasing one may be convenient -- and cheaper -- resist the urge. "They're notoriously inaccurate," say Tom and Ray Magliozzi, hosts of the National Public Radio program "Car Talk." They also say it's best to stay away from the pressure gauges attached to the air hose at the gas station.
They are not alone in this advice. One consumer testing organization confirms that pencil tire gauges are not as accurate as dial or digital. Consumers agree. At Amazon.com, several users say they are much happier after switching to another style of tire gauge. One customer who bought a digital gauge says: "I was tired of using those 'stick-style' pressure gauges. I never felt those gave an accurate reading since over time it seems that it became easier for those sticks to shoot out."
We analyzed hundreds of customer reviews from Amazon.com, which sells Accutire, Joes Racing, Moroso and many other tire gauge brands. Consumer Reports tests digital, dial and stick tire gauges for its review, which is available to subscribers. Popular Mechanics includes the Accutire MS-4021B in its list of 15 Must-Have Car Gadgets, and Car and Driver rates five top tire gauges in a comparison test. Information on how to find the best tire gauge and other tips come from Motorcycle Consumer News, as well as Tom and Ray Magliozzi, hosts of the radio program "Car Talk".