Saturday, July 14, 2012

Accutire Model MS-4021B Tire Pressure Gauge Review

First Impressions and Images
Here's the second of the two tire pressure gauges I recently got, the Accutire MS-4021B. (The other was the Joe's Racing 32307 gauge, a mechanical dial-type gauge. Find that review here: Review of Joe's Racing 32307 Tire Pressure Gauge.)

The Accutire is a lightweight plastic model that got top marks from Comsumer Reports (not that that means much, see this post on why I think Consumer Reports sucks: Why Consumer Reports Sucks.) It has a soft-touch plastic handle, negative LCD display with red backlight, measures about 6.5" from the end of the handle to the chuck, and is made in China.

It runs on three LR44 1.5 volt button cell batteries, which can be swapped out by removing the battery cover on the back of the handle. Click here for a how-to with photos of the battery changing process. Also on the back are a sticker with what I assume is the date of manufacture and another sticker with the FCC information for the device. There is no on or off switch, the unit turns itself on automatically when you press it to a tire valve and shuts off a few seconds after displaying the pressure reading.

Here's a top view. There is a handy detent to rest your thumb on when taking a pressure, letting you apply force directly in line with the chuck. You can also see the two-part plastic construction seam that runs the length of the unit.

Here's the plastic chuck. The entire unit is fairly lightweight, but I think if you dropped it on the chuck or stepped on it by accident it would probably break. Also it does not swivel or move in any way, so it can be awkward to line it up perfectly with a valve stem. Still, it's easy enough to get a good seal, and I never had a problem maintaining a leak-free fit on the tire stem. It is actually less finicky than the Joe's Racing gauge.

The negative LCD display measures 1-7/8" x 1/2", and the digits are easy to read at arm's length, even in direct sunlight. You can't see the red backlight in these brightly lit images but it does have a reddish color when you're using it in a dim garage.

Using this Gauge
Here's a shot of the unit in action - basically, using a pressure gauge does not get easier than this. It turns itself on and off and displays the pressure clearly without any guesswork or thinking by the user. There are no moving parts to wear out. It shows the pressure for about 4 seconds after you remove it from the valve stem. It automatically calibrates itself after taking a reading (you'll never need to follow the confusing "zero set" directions on the package). It fits in a cargo pocket or your glove compartment. It's also dirt cheap, and if you accidentally backed it over or if you had a glovebox meltdown I wouldn't be heartbroken about replacing it. The package says it has a five-year warranty. You can actually replace the batteries yourself when they wear out. That's a lot of high points for a gauge that only costs about $10.

The package states that this unit measures from 5-150 psi in temps of 0-100 degrees F with and accuracy or +/- 1% + 0.5. I take that to mean that it has a 1% margin of error over the 145 psi range, or a maximum of 1.45 psi off from the true value at any given psi. This is comparable to published stats from other digital and analog gauges that cost quite a bit more, so for the price this gauge is plenty accurate.

The Final Word
This is an especially user-friendly gauge that also happens to be especially cheap. I would keep a more expensive dial-type gauge around in the garage and throw this one in the car so you always have one along. Overall I would not hesitate to recommend this gauge to anyone.


  1. I've read in another review that the three replacable batteries only power the light. The pressure gauge is powered by a non-user replaceable lithium battery that will last about 5 years of normal use.

    1. Hey, thanks for your comment. I guess it's possible that the gauge is powered by another internal battery, but the gauge I bought for this review is still working so I don't want to wreck it to find out!

    2. I removed the batteries and tried to take a pressure reading but nothing. The display is dead, even if you shine a flashlight to it. This seems to go against the idea that the batteries only serve to light up the LED.

  2. If accuracy type is not specified, it usually means percentage of reading. So roughly, from 0-145 psi, the worse case is 2 psi at the top end of the scale. Since car tires are about 25-35 psi, it effectively means ~ +/- 1 psi.

    There are several cons for this model gauge. If you check Consumer Reports and Amazon, the quality control varies quite a bit, you can get a dead gauge or one that dies soon. Also, they are not durable if you leave it in your car in the heat of summer, it will drift off calibration or break the plastic. With the battery dying in 5 years or so even if you take care of it, it has planned obsolescence. There is no self reset when you change the battery, so even if you do try to do it some lock up. These are some issues as you mention Consumer Reports doesn't check: long term reliability or quality control.

    The most durable for leaving in a car still is a good pencil gauge, for $3, it will last you a lifetime, I have several over 20 years old, all working well; just keep it clean and oil it if it gets dry - the shaft of the gauge must always have an oily film on it.

    That said, I do have a Husky digital gauge, but I use it at home with my air pump to check the accuracy of the pencil gauges, and unlike the Accutire, made sure it didn't have an unremoveable battery and that is resets when you remove the battery. I think Accutire makes most of these gauges, but at least this is a more recent design.

    You blog comes out high on a google search doing Accutire + consumer reports.

  3. Wrong on Consumer Reports. It's an excellent and unbiased source of consumer product reviews and ratings. For a blog author to make the high schoolish claim that "it sucks" without any reason why, makes you look silly and not serious.

    1. I agree, Consumers Report does not accept advertising and is an unbiased report. This is the only company I trust when it comes to testing and reporting accurate information. The rest of those "so called" testing agencies that accept advertising is based on opinions, which is worthless as the paper it's printed on!

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  5. I had two of these air gauges I kept in the consoles of our cars. Accurate enough and quick to use. The handle shape contributes to a good seal. The only problem I had with both of them was the rubbery grips became very sticky over time, perhaps from heat during south Louisiana summers...

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