For those of us who actively buy tools that we know we won’t use on a near-daily basis, there are really two schools of thought. While it’s nice to buy the nice racing pit crew-quality stuff and keep it forever, the financial constraints of the real world mean that few of us have blank checks to write, and affordable tools should get the job done. After all, a $200 tire pressure gauge probably isn’t 20 times better than a $10 tire pressure gauge, right? Well, this YouTube video tested a bunch of gauges at a bunch of price points to figure out the best bang for your buck.
On the chance you haven’t binge-watched Project Farm on YouTube, open up like 35 tabs once you’re done reading this article because I promise it’s both addictive and informative. This channel’s all about independent, unbiased testing of stuff you might use at home, in the garage, or on your vehicle, from headlight restoration kits to non-stick frying pans. A few months ago, Project Farm took on the task of comparing 23 affordable tire pressure gauges using a pressurized air tank and a manifold with two pretty high-end calibrated and certified SSI digital pressure gauges attached as points of reference.
This testing’s resulted in a few interesting observations, most notable of which is that tire pressure gauge accuracy can vary even across two seemingly identical gauges. Same style, same brand, but one might read higher or lower than another. That’s not a great sign of quality control. On the plus side, a lot of the pencil-type gauges actually seem to perform very well, even if they aren’t the easiest tire pressure gauges to read. Most of the digital gauges also proved to be quite accurate, and although replacing batteries in a tire pressure gauge sounds like a pain, having a backlit display seems like a godsend if you’re checking your tire pressures in a dark garage. The accuracy of most digital tire pressure gauges shouldn’t be surprising, but it’s reassuring that testing seems to back up a gut theory.
As you’d probably expect, the fluid-filled Slime dial-type gauge doesn’t seem to like prolonged cold temperature exposure, which makes sense considering how temperature affects the thickness of a fluid. Hot maple syrup flows over pancakes a whole lot easier than cold maple syrup, and warm engine oil flows better than frigid cold engine oil, so this finding seems to make sense. Speaking of cold weather, it’s also not surprising that one of the Rhino USA digital gauges didn’t work after being frozen as cheap electronics don’t like cold and moisture, although it was surprising to see one of the DeWalt pencil gauges undergo, um, unscheduled rapid disassembly after being frozen. Looking at the disassembled gauge, it seems to largely be a pressure-fit design, so it’s possible the rubber O-rings just became brittle in the cold and stopped sealing.
So, do you have to pay top-dollar for a truly accurate tire pressure gauge in order to ensure safe inflation? Well, not quite, since tire pressure reading one PSI or so off of spec usually isn’t the end of the world. After all, the air in your tire heats up and expands as you drive, which is why a pressure reading from cold after you’ve parked your car overnight is usually substantially lower than a hot reading, taken after you’ve been driving for several miles. However, some of these gauges are more than just one or two PSI off, and that amount of deviation can cause some serious issues. Take the second Rhino USA digital gauge tested, which read 9.3 PSI low on the 40 PSI test, or a whopping 23 percent lower than the actual pressure in the tire.
If the pressure printed on your door jamb is 40 PSI and you use a gauge like this one, what appears to be 40 PSI could actually be pushing up against the maximum pressure your actual tires are capable of handling. Overinflation can lead to accelerated wear in the center of your tread, poor ride quality, and an increase chance of tire failure due to road impacts like large potholes, not to mention reduced traction. Worse still, your tire pressure monitoring system might not alert you to overinflation, as the air pressure in your tires would still be above target.
At the same time, a gauge that reads substantially high could result in some problems, especially if you’re likely to load your vehicle up to near its rated payload capacity. The amount of load a tire can handle depends on its pressure, and an overloaded tire could spell bad news on the open road. Take it from someone who’s experienced a few due to appalling infrastructure, blowouts at speed aren’t fun. In addition, underinflated tires will sap fuel economy, can affect your vehicle’s handling, and can wear down the shoulders of your tires faster than you’d expect. Thankfully, every light-duty vehicle sold in America starting in Sept. 2007 has tire pressure monitoring that’ll alert you if your tire pressure is too low, but Canadians and owners of older vehicles might not have that safety net.
It’s also worth noting that if you’ve changed the wheel and tire size on your vehicle, you really want to go back and recalculate your tire pressures as different tire sizes have different load ratings. For instance, I run 225/40R18 XL tires on all four corners of my BMW, and since the factory rear tire size is 255/40R17, I’ve had to hike the rear tire pressure from 38 psi to 42 psi in order to achieve a safe load capacity. For most aftermarket applications, TireSize.com has a properly handy calculator that removes a lot of guesswork when it comes to load capacity.
So what have we learned from Project Farm’s testing? Well, sticking with name brand and not buying the absolute cheapest tire pressure gauge money can buy seems to usually yield better results. Judging by how the testing went, the Jaco digital gauge seems expensive but maybe worth it at $28. At the same time, the CZC Auto pencil gauge is impressive, with a $9 as-tested price, zero reliance on electronics, and nearly a podium finish when it came to accuracy. At the same time, if you carry a cheap dial-type gauge in your glovebox, it might not be as consistent as you’d expect, as analog dial-type gauges were frequently outperformed by many pencil-style and digital tire pressure gauges. However, if you didn’t just pick up the cheapest tire pressure gauge you could find at Dollar General, what you already have might just be accurate enough. Checking your pressure with a cheap gauge is better than never checking your tire pressure at all, and there’s a high likelihood your car has a tire pressure monitoring system that’ll alert you if your tire pressure gets way too low.
(Photo credits: Project Farm/YouTube, Thomas Hundal, AndreyPopov/depositphotos.com)
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My local Discount Tire has a free compressor for use, and my Equinox
has a metered TPMS. With a slow leak in a couple of tires, I’ve used DT’s
compressor often enough that the 100-plus-year-old Chevy dealer’s service
department compliments me on maintaining my tire pressure when I’m in
for an oil change or other service.
At Discount, I select pressure desired digitally, press ‘GO’, then inflate.
There’s a repeated beeping when pressure is met. Repeat for any additional tires.
When all is said and done, I’ve never been more than 1 inch/pound of pressure
between Discount’s compressor and the vehicle’s TPMS readings, which has
repeatedly been confirmed by said over-100-year-old Chevy dealer’s
service department: Berger Chevrolet in Grand Rapids, Michigan
Because Discount Tire is less than a quarter-mile from where I live
and their compressor’s accuracy has proven correct against my car’s
TPMS and a dealer’s readings, I’ll continue to use Discount’s generousity
as needed. It’s easy, quick, and free.
I guess it’s just me, but the PF guy’s livestock-auctioneer delivery makes me want to curl up with a warm bottle of Bourbon and drag my fingernails on a chalkboard to relax.
I can’t get through a single one of his videos.
I’d LOVE a similar review/thoughtpiece on aftermarket TPMS systems…
It’s almost annoying to hear that those pencil gauges are so accurate. When I was a pump jockey teen, I hated them so much because I never felt they were correct. It was almost certainly user error. I much preferred the window gauge on the hose chuck, but now I think I probably mis-inflated thousands of tires instead.
However, I did get pretty good at guessing how full a tire was by the amount of radial bulge each had. I could pretty much tell as car pulled up to the full service pumps.
Unimportantly (sic), in the 1980’s, two kinds of people used full service pumps in my area. Wealthy, happy, kind, patient people or the absolutely most miserable motherfuckers (sic) looking to abuse you for an extra three cents a gallon. The difference was stark. Some people got a little air let out of their tires before they drove away (hehehe). I was tempted to add washer fluid to oil, but didn’t want to get the station in trouble.
Accutire gauges are nice.
Milton pencil gauge. Accurate, made in America and they’re like $10.
I just want it to show the same value for all 4 tires, even the 1 dollar China plastic ones can do that!
Standard part of my extended classic car tools set in all my cars.
I have a decent quality one in the workshop.
I have an analog dial Slime-branded gauge. I don’t know if it’s accurate, but it always matches up with the pressure I select on the gas station pumps I sometimes use.
Yeah who do you trust? I have a couple of digital gauges, a dial type inflator for the big compressor, and a Milwaukee M12 Inflator. Meanwhile many of our cars have TMPS that I can either read in the screen or use a scan tool. None of them agree, the dial one for example is 2psi high vs the car’s readings and that is consistent from vehicle to vehicle. The Milwaukee reads 1psi higher than the vehicles. The two digitals only read in .5psi increments and seem to be pretty close to the car.
So yeah on the cars where I can check via their sensors that is what use for the regular checks. On the others I use which ever digital I find, or for the winter bump just drag out the Milwaukee and set it 1 psi high.
I don’t know if it has been mentioned, but how accurate is the TPMS in modern cars? I have an analog gauge which I feel is hilariously wrong, the gauge on my pump, a small hand held digital gauge (similar to one in the photos) and the TPMS my car came with. When I check the pressure, each one is off by quite a bit, however, the hand held digital gauge and the car’s onboard are usually pretty close, and typically rely on those when I am checking.
Project Farm is just good useful entertainment, something that is short supply in our information flooded world of screens.
Tire pressure is probably not too critical in most street vehicles, but a couple of psi error can cause nasty instability in some types of motorsport.
I dunno, just being 1.5psi off will send your M3 flying over the median. 😉
Consumer Reports recommended the Accutire digital gauges, that is what I have now. They are consistent and agree with each other and the gauge on my ViAir inflator. $10 apiece, the battery replacement in less than two years will be $8. Bit silly that, bought a 20-pack of the required batteries to go on with.
Making $0.01–$0.02 per day from home has been such a rewarding experience! I only need a computer and an entire day, and I finally have the lack of flexibility I’ve always wanted. Let me know if you’re interested—I’d be happy to help you get started losing money like me.
Nicely edited!!
For those of us who off-road, having a good tire gauge is important. On gravel washboards, airing down to 15-18 psi is the difference between keeping your fillings in your teeth and not, but too soft and you risk de-beading the tire. I use the built-in gauge on my portable ARB compressor but I double check it with a stick gauge.
Airing down and airing back up at the off road park was how I found out my main gage was bad. I keep 2-3 in the jeep now.