After putting in more than 40 hours of research and testing 17 portable air compressors, we recommend the Viair 77P as the best tire inflator for most drivers, because it offers great performance in a user-friendly, durable, and affordable package. It was among the quickest and quietest models we tested, it has an accurate and legible pressure gauge, and it has a solid metal body that belies its affordable price.
The Viair 77P comes with a 45-inch air hose and a lengthy power cord, so you can easily reach any tire on the vehicle. It also has a built-in work light, so you can see what you’re doing at night. It stays stable and well-planted when running, too, whereas some other tested compressors vibrated a lot during operation, causing them to “walk around” on the asphalt. Its 30-minute continuous operating time is twice as long as most competitors’ and ensures that you’ll be able to fill every tire in one go, with time to spare. And it comes with a handy carrying case. The 77P’s only drawback is that its gauge goes up to only 80 psi. This isn’t a concern for car tires, but it does limit the tool’s utility for some other applications, such as some bicycle or RV tires.
If you need a tire inflator with a higher-psi gauge than the Viair 77P has, we recommend the BonAire AirTech Professional (ATP50), which reads up to 250 psi. This feature makes it easier to inflate tires that require higher pressures than 80 psi, such as those of road bikes or RVs. The ATP50 was one of the quickest competitors in inflating our test tires, and it remained stable during operation. It also has a 25½-inch hose, and it was one of only three models we tested that offered an auto-shutoff function. We found the digital gauge easy to read and among the more accurate ones we saw, and you can detach the gauge from the unit to use it independently. Next to our top pick, the BonAire is noisier and slower, its air hose and power cord aren’t as long, and it’s made of plastic instead of metal, although it still feels sturdy. It also doesn’t have a work light. The Craftsman 12V Portable Inflator is virtually identical to the BonAire, and it’s another solid choice if our runner-up is out of stock or higher priced.
If you’re willing to give up the great performance of the Viair 77P to save a few bucks, the Slime Tire Inflator (40032) will do the job, but it’s a lot louder and not as user-friendly. Despite being one of the least expensive models we tested, this compact, lightweight inflator was quick to top up our underinflated tire. It has a relatively long hose (24½ inches) and a large, easy-to-read gauge. It was also stable during operation, not moving around like some others. However, it was one of the loudest of the group and we found it hard to stuff the cord and hose back into its small storage cavity after using it. The pressure gauge goes up to only 100 psi, which is fine for cars and trucks, but won’t work for some bicycles, RVs, or commercial trucks.
If you want a cordless tire inflator that you can just grab and go, without having to plug it into a power source, we recommend the Slime Rechargeable Tire Inflator (40033). It works well and can run off of its internal lead-acid battery or be plugged into a vehicle’s 12-volt power outlet. The 120 psi gauge is easy to read. The long 24-inch hose makes it easy to reach any tire, and, unlike many models, it’s easy to store. This Slime model is also the smallest and lightest of several lead-acid cordless models that we tested, so it’s easy to take along and won’t take up too much space in your vehicle. This Slime model doesn’t have a work light, though, and its 6-foot, 3-inch DC power cord is relatively short, although we had no trouble reaching all the tires on our test cars when plugged in.
I was the automotive editor for Consumer Reports for 14 years, where I edited the publication’s car reviews and auto-accessory tests. Prior to that, I was the senior feature editor for Motor Trend for nine years, where I wrote a monthly column about car care and maintenance. As a previous off-road enthusiast, someone who has to deal with the temperature swings of the northeast, and a guy who has a knack for driving vehicles that develop a slow leak in at least one tire, I’ve consistently used portable tire inflators for the last 20 years. For this test, I equipped myself with a digital tire-pressure gauge, stopwatch, sound meter, and tire valve tool to test 17 portable air compressors of different types to see which deliver the best combination of performance, value, and ease of use.
If you drive a car, it’s likely that you’ll find a portable tire inflator handy. That’s because all tires lose air pressure for various reasons, whether slowly, due to the normal seepage of air through the tire’s rubber, or more quickly, due to a slow leak or a drop in the ambient air temperature. And having a small air compressor to inflate the tires is the quickest and easiest way to set them right. It keeps you from having to drive to a gas station to add air—and hope that the weather isn’t bad … and that the station has an air compressor that’s working … that isn’t too grimey … and doesn’t cost much money.
Keeping your tires properly inflated is a real safety concern. As we describe in our guide to buying tires, tires can lose air pressure so gradually that many drivers aren’t aware of it. And underinflated tires can be a safety risk, making your car handle poorly, making it harder to keep control when swerving to avoid an obstacle in the road, or by causing a tire to fail—and possibly cause a blowout—due to overheating. Underinflated tires also use more energy, which hurts your car’s fuel economy.
Most experts recommend checking your tires’ pressure at least once per month with a good tire-pressure gauge, and more often if you have a slow leak. As a backup, all new cars now come with a tire-pressure monitoring system (TPMS) that’s designed to alert you if a tire’s pressure drops by about 25 percent. If a tire warning light goes on in the dash, having a tire inflator handy makes this a quick fix rather than an inconvenient trek.
These portable air compressors are also handy for other uses, such as inflating the tires on bicycles, recreation vehicles, trailers, riding lawn mowers, and even wheelbarrows. Because they come with extra inflator tips, they can also quickly pump up basketballs, footballs, soccer balls, and the like, or be used for inflatable mattresses, toys, yard decorations, or other inflatable items you have around.
By the way, the packaging on some inflators touts high psi numbers that can make you think that they are more powerful compressors. But that’s not always the case, and those figures can be misleading. Keep in mind that a high psi number really only means that’s what the gauge can measure, not necessarily what the inflator itself is actually capable of. Most car tires require about 32 to 40 psi so you probably don’t need to worry about this. But, if you need to inflate your road bike or RV tires to, say, 120 psi, you’ll want a model with a gauge that can measure at least that high, if not higher (allowing for some inaccuracy in the gauge). In fact, you might be better served by a gauge that goes up to 150 or 200; just don’t expect to actually achieve those pressures at the top of its range.
We started by spending several days researching the category, reviewing existing articles about portable air compressors (there aren’t many), and comparing the specs and features of about 50 different models at varying prices and using different power sources. We narrowed that list to the most promising ones by eliminating models that didn’t seem to provide enough useful features for the money, aren’t readily available from mainstream retailers, or had few or subpar user reviews.
In choosing models that are best for most drivers, we leaned toward ones that plug into a car’s 12-volt outlet. That’s because they tend to be more compact and easier to carry around in a vehicle and still deliver good performance. The heavier-duty models that connect to a car’s battery are generally good performers, but they are larger and pricier and many people aren’t comfortable getting under the hood to connect a device to the battery.
We then gathered 17 inflators to test and put each through a series of tests that let us assess them on key criteria.
Gauge accuracy: An accurate gauge is important for precisely inflating your tires to the desired pressure (or for the compressor’s auto-shutoff to kick in at the right time). We measured this by filling the test tires to their recommended pressure, as indicated on each inflator’s gauge, and then double-checking the tire pressure with a separate digital tire-pressure gauge. Relatively few inflator gauges were spot-on with our gauge, but most were within 1 psi of the indicated pressure.
We did find that a number of units give you different readings, depending on whether the air compressor is running or stopped. When this is the case, stopping the inflator gave us the most accurate results. When the Slime 2X Tire Inflator (40026) showed 32 psi on its gauge while running, for example, we measured only 26 on our digital tire-pressure gauge. But if we stopped the device and checked, we measured a much better 31.
Gauge legibility: Knowing when to stop is crucial for accurately inflating your tires, so you want your pressure gauge to be legible. The compressors with smaller gauges that go up to 200, 250, or even 300 psi tend to be the most difficult because the numbers are squeezed too closely. Adding to the problem is that some units don’t have markings between the 5- or 10-psi increments, so stopping the inflator at, say, 32 psi, takes some guesswork. Digital readouts tend to be easier to read. Illumination is also a nice bonus.
Inflation time: If you need to adjust a tire’s inflation pressure, you want to get it done as quickly as possible. We timed how long each unit took to inflate two different tires to their recommended pressure. The first was a 15-inch tire from a midsize car that was completely flat and needed to be inflated to 32 psi. The second was an underinflated 20-inch tire from a large SUV that simulated one that triggered a tire-pressure warning light in the dash and needed to be inflated from 26 psi to 35 psi. This is a common scenario, because all new cars now come with a TPMS that typically alerts drivers if a tire’s pressure drops by 25 percent.
Heavier-duty models that connect directly to a battery’s terminals were the quickest for inflating the flat tire, all in under 2 minutes. Among less expensive, more mainstream models, our top pick, the Viair 77P was quickest at a little under 3 minutes. Most models ranged from about 4 to 8 minutes, although the lithium-ion-powered Bolt Power took about 10.5 minutes and the small Slime Tire Top Off (40020) required more than 11 minutes. Inflating the “low” tire typically took about 1½ to 4 minutes.
Hose and power cord length: We didn’t have any trouble reaching all four tires on our test vehicles with any of the models. But longer hoses and cords give you more flexibility for different situations. Hose length varied from only 4 inches to a lengthy 30 feet, with most models having hoses that stretched 18 to 26 inches. The power cords ranged from 21 inches to 16 feet, although most had power cords that extended a reasonable 8 to 11 feet. The only problems we saw were with models that made it hard to stow the cord or hose when not in use. Some units include a storage cavity that’s too small, and we had to stuff the hose or cord in to keep it from dangling.
Portability: Most of the units we tested are pretty light, with the smallest weighing less than a pound and the heaviest—the PowerStation PSX-3 combo model—weighing more than 19 pounds. Most weigh about 2 to 6 pounds. Some models are also easier to carry than others; a handle or carrying case is a welcome feature.
Noise level: When kneeling over an inflator, keeping an eye on the inflation pressure, a noisy compressor can get annoying. That’s why we measured the sound level of each unit while operating from a distance of two feet (where your head might be when looking at the gauge). We saw the lowest noise level from our top pick, the Viair 77P, which we measured at only 65 decibels, or about the same level as an air conditioner or vacuum cleaner. All of the others were much louder, ranging from 76 to 85 decibels. The latter is four times as loud as the 77P and about the same level as an idling bulldozer or a diesel truck driving past from 50 feet away.
Build quality: Most of the models we considered were plenty sturdy, but there were some exceptions. On the chintzier end, some vibrated so much that they “walked around” a bit while operating, which made reading the gauge difficult.
Continuous run time: Though we didn’t measure the duty cycle of our models, we did note how long you can run the units continuously, according to the manufacturers, before you need to shut them off and let them cool down. That’s because compressors heat up during use, and they can be damaged if they overheat. Most manufacturers advise not to run the units continuously for more than 10 to 15 minutes, after which you should let them cool for about 10 to 30 minutes. The most notable exceptions were the Viair models, which can run for about 25 to 40 minutes, depending on the model. A couple also include a thermal shutoff to further protect them from damage.
We saw a wide range of performance and quality in the 17 tire inflators we tested, but the Viair 77P stood out from the rest, thanks to its combination of quick performance, solid construction, handy features, and good value. It was the quickest at inflating tires among 11 lower-priced models that cost $50 or less. Its illuminated gauge is very easy to read and more accurate than most. It was easily the quietest of the models we tested. It has a high-quality metal construction (most portable compressors have all-plastic cases). It can operate for up to 30 minutes at a time; most others are limited to 10 to 15 minutes. And it comes with a handy carrying case, unlike most models in this price range.
Despite its strong performance, the 77P, which plugs into a car’s 12-volt power outlet, is pretty compact. At 7 inches long and about 5 inches tall, it’s about the size of a couple external desktop hard drives placed side by side. So, it won’t take up much room in your car’s trunk or cargo area if you want to carry it in your vehicle. Its 45-inch air hose is one of the longest of the models we tested, and its 16-foot power cord is the longest. These make reaching any tire on a typical passenger vehicle easy. The handy case—with an internal pocket for holding small items—keeps everything contained and makes it easy to carry around. But it’s snug; The unit, cord, and hose fit in with little wiggle room.
In contrast with the plastic cases of most of the other models, the 77P’s solid metal casing gives a reassuring impression of quality. It’s accented with plastic trim that has a tasteful matte texture. Extra needles are held in place at the base. And flexible rubber “feet” kept the 77P from moving around on the asphalt when operating (again, some models tended to walk around on the pavement, which didn’t affect their performance but was annoying). The 77P also has a work light integrated into the end of the case, which is handy in low-light situations.
An illuminated pressure gauge, integrated into the thick handle on top, has large numbers and is segmented into 2-psi markings (many others show only 5- or 10-psi increments). All of this makes it one of the easiest to read, even when we were standing up. In our tests, the gauge was one of the more accurate ones; when it read 32 psi, we measured 31.5 on a separate digital tire-pressure gauge; when it read 35, it was spot on. Moreover, the gauge gave us the same reading whether the compressor was running or not, which is a refreshing change from many models that show one reading when running and another when stopped. The gauge goes up to only 80 psi, however, which is fine for passenger vehicles but can be limiting for other applications.
Though most of the non-Viair models are limited to 10 to 15 minutes of continuous running time before needing to be cooled down, the 77P can run for 30 minutes (although these duty cycles vary depending on the ambient temperature and pressure being pumped out). This gives you more flexibility when working with multiple tires. The 77P also has a thermal cutoff built in, so it will automatically shut off if it reaches a predetermined temperature.
In our tests, it took the 77P a little less than 3 minutes to inflate a completely flat tire to 32 psi. This was about half the time of most of the other under-$50 models. In our “underinflated” tire test (reflecting the pressure at which a tire-pressure warning light would come on in the dash), it took less than 1½ minutes to boost the pressure from 25 percent down (26 psi) to full (35 psi).
With this exceptional performance, we’d be willing to put up with a little extra compressor noise when using the 77P. But, surprisingly, it was the quietest of the group by a wide margin. We measured only 65 decibels from two feet away, which is a moderate level that’s considered in between an air conditioner and a vacuum cleaner. Most other models were 80 decibels or higher, which is twice as loud as 70 decibels and about the same as a garbage disposal or dishwasher.
As mentioned above, the only notable drawback with the Viair 77P is that its pressure gauge goes up to only 80 psi, yet most others we looked at go up to 120 psi or higher. If you’ll use it to inflate car tires, that’s not a problem. But that gauge won’t help you when inflating the tires of some bicycles or RVs that need to go over that figure. Viair’s website says that the 77P is intended to inflate tires up to size 225/60R18 (18 inches in diameter), but we see that as conservative. We used it on larger 20-inch SUV tires with no problem.
If you want an inflator with a gauge that goes higher than 80 psi, we recommend the BonAire AirTech Professional (model ATP50). It has a digital tire-pressure gauge that goes up to 250 psi and can be removed from the unit for checking tires separately. The gauge’s digital display is easy to read, showing the pressure in 0.5-psi increments. In our tests it was also one of the more accurate gauges in the group, although we had to turn off the compressor to get an accurate reading. Otherwise it read 2 psi or so high, which the instructions attribute to air-hose back pressure.
The BonAire provided decent inflation times: about 6 minutes for our flat tire and about 2½ minutes for our underinflated tire. It has a long, 25½-inch air hose, and the hose, cord, and extra needles are easy to store in the case (something we can’t say about many models). The BonAire is also one of only three models in our test group that have an automatic shutoff, so you can set it up, turn it on, and walk away. That’s a nice feature that we expected to find on more models. The BonAire doesn’t have a work light, though, so you’ll need your own light if working in the dark. We also tested the Craftsman 12V Portable Inflator, which is virtually identical to the BonAire and gave us slightly quicker inflation times. The Craftsman is another good choice if the BonAire is unavailable or priced higher.
If you’re really pinched for cash, we recommend the Slime Tire Inflator (40032), which is one of the least expensive models we tested (although not as good of an overall value as the Viair 77P). This compact, lightweight unit is more user-friendly than other budget-priced models, with a bright work light and integrated handle for easy carrying. The gauge is large and divided into 2½-psi increments, which makes reading precise pressures easier than with many models. It goes up to only 100 psi, though, which is fine for passenger vehicles but too low for some bicycles or other applications.
This Slime unit has a relatively long 24½-inch hose, was stable during operation, and provided decent inflation times—about 7 minutes for our flat tire and a little under 3 minutes for our underinflated tire. It was one of the loudest models we tested, however, and we found it hard to stuff the cord and hose back into the small storage cavity on the side of the case.
If you don’t want to be tied to a plug-in power source, we suggest considering the Slime Rechargeable Tire Inflator (40033). This dual-power unit has an internal lead-acid battery that lets you use it without having to mess with a power cord. This is convenient when you don’t have a vehicle or AC outlet nearby, or you just want to be able to grab it and connect, without a lot of fuss or time. You’re also still covered if its battery gets too run down to operate the compressor, because you can also plug the unit into a car’s 12-volt power outlet for juice. We tested two other models with internal lead-acid batteries, but this was the smallest, lightest, and easiest to store in a car.
The lithium-ion–powered Bolt Power D28A is another lightweight, cordless model, but the Slime Rechargeable is much quicker and easier to use for inflating tires. It has a 24-inch air hose that has an integrated gauge and is easy to store in the case. The power cord is a relatively short 6 feet, 3 inches, but hopefully you won’t need to use it that much. The 120 psi gauge is easy to read, although it has no markings between the 5-psi increments. One drawback is that the unit doesn’t have a work light.
Models that plug into a car’s 12V outlet:
We like that the Black + Decker High Performance Inflator can be powered through either a car’s 12-volt outlet or a household AC outlet and that it inflated tires quickly and stayed put while doing it. But it has an borderline-illegible gauge that’s inaccurate when running, and its rounded shape and lack of a handle make it difficult to carry.
The Kensun YS-205 is another dual-power model that can be plugged into a car’s 12-volt DC outlet or a household AC outlet. But its gauge is very inaccurate and hard to read, especially while operating. The unit also vibrated around a lot on the pavement when running.
The AAA Air Compressor is one of the least expensive models we tested, but it was one of the loudest and the unit vibrated around a lot on the asphalt while operating. The small markings on the gauge made it hard to read. And though the unit came with extra needles for inflating various things, there’s no place to store them, so they could be easily lost.
The Campbell Hausfeld 12 Volt Tire Inflator is one of three models we tested with an automatic shutoff. But it was the chintziest and one of the loudest models we tested. It was also one of the slowest at inflating our test tires, and it scooted around the asphalt while in use.
Models that connect to a car battery:
These models tend to be heavier-duty and pricier, and are often marketed for use with recreation, off-road, farm, and commercial vehicles (as well as motorcycles), which don’t have a 12-volt outlet. If you don’t mind getting under a hood and connecting a device to the battery, they might be good options for you. But this requirement and their higher prices made us look elsewhere for our picks for most drivers.
The Viair 450P is the best model we tested overall, but it’s also the most expensive by a wide margin and is overkill for most drivers. It has a solid, all-metal construction and is one of the quickest and quietest. Its ultra-long 30-foot coiled air hose gives you extra flexibility, and it can run up to 40 minutes without stopping (most others can run for only 10 to 15 minutes). One big benefit: Its pistol grip, with a bleeder valve and a large gauge, makes it super easy to add or bleed out air to get the right pressure, without having to be near the compressor. Viair’s website says that it can inflate up to 42-inch tires.
The Viair 88P has solid, high-quality construction and was one of the quickest at inflating our test tires. It can run for a long 25 minutes without stopping, and Viair’s website says it can handle up to 33-inch tires. When running, however, the gauge read way too high, so we had to keep turning it off to get a good reading. Also, its work light faces toward you when you’re reading the gauge, so you can’t read the gauge and light the work area at the same time.
Like the Viair 450P, the Slime 2X Tire Inflator (40026) has a long coiled air hose that lets you work farther away from a power source than most other inflators do. It was very easy to use overall, and was one of the quickest at inflating our test tires, as well as one of the quietest. One gripe: Getting an accurate reading requires stopping the unit, and, because the gauge is at the end of the long hose, you need to move back and forth to stop the unit, read the gauge, and then turn it back on if necessary.
The Slime 120V Tire Inflator (40029) was the only model we tested that ran on AC power only. If you don’t want to carry an inflator in your car and will be using it only near a household outlet, this may work for you. It gave us relatively quick inflation times, although the gauge read high by a couple psi in our tests, and it was one of the loudest units we tested. It can be mounted on a wall and includes two USB ports and a set of adapters for charging personal electronics.
In addition to inflating tires, these models can also jump-start car batteries and charge electronic devices. Because they’re battery powered, they don’t need to be plugged in, which makes them handy for grab-and-go tasks. The larger models, with an internal lead-acid battery, were the best for inflating tires, but they’re too hefty to conveniently carry in your car. The smaller lithium-ion Bolt Power is easier to stow, but it didn’t perform that well as a tire inflator. If you want to carry an inflator in your car and have the ability to jump-start a car, we recommend getting separate units that are specifically designed for those tasks.
The Stanley JumpIt 1000A is the smallest, lightest, and least expensive of the two lead-acid combo models we tested. It has an adjustable work light, an illuminated gauge, a 12-volt power outlet, and a USB port. It was also reasonably quick in inflating our test tires and the gauge is fairly accurate. One quibble we had is that there’s no place on the unit to store the DC charger, which means it could easily be misplaced.
The PowerStation PSX-3 is the heaviest and largest model we tested, as well as one of the priciest. It’s easy to use and performs very well, delivering some of the quickest inflation times we saw and spot-on accuracy. It has a 12-volt power outlet and USB port for powering or charging other items, and the internal battery can be charged by using either an extension cord plugged into an AC outlet or by plugging it into a car’s 12-volt power outlet.
The main intention of the lithium-ion Bolt Power D28A Jump Starter, one of the pricier models we tested, is to jump-start cars. To inflate a tire, you need to plug its tiny compressor into the power pack. But it has a very short air hose and was one of the slowest at inflating our test tires. The gauge read about 4 to 5 psi too high in our tests and it goes up to only 80 psi. We’re also including this Bolt Power in our in-the-works guide to portable jump-starters, so we’ll soon be able to tell you how it compares in its main job function.
These pint-size models can be easily carried in a vehicle’s glovebox, center console bin, or cargo-area cubby.
The Wagan Tech Quick Flow provided reasonable inflation times, but its gauge was hard to read and off by about 3 psi. Also, it vibrated around a lot on the pavement, and you can’t have the compressor and work light on at the same time, as they’re controlled by the same either-or rocker switch.
The Slime Tire Top Off (40020) is the smallest, lightest, and cheapest model we tested. But it has an ultrashort air hose and was one of the slowest at inflating our tires. Its gauge was off by about 4 psi and the work light is on the opposite side from the hose, so it points away from the tire valve while in use.
(Photos by Rik Paul.)
Originally published: February 15, 2017