A test of budget tire compressors: the wrong bees
They buzz a lot, but are of little use. Among 12 samples of available (not more than 2000 rubles) car compressors, a third turned out to be “wrong”. Is it worth to buy inexpensive models?
In the cartoon, Piglet tried to inflate a balloon for his friend, the bear, but it did not work. The little piggy almost burst from the strain. But will not burst for the same reason, small inexpensive compressors?
We did not put a price limit on it for nothing: Many people today are looking for something cheaper. So, we are going to look for budget models – not more expensive than two thousand rubles. Imagine, there are a dozen of them.
Getting ahead of ourselves, we can say that the four compressors were much worse off than Piglet. Curiously enough, the name of one of the losers can be translated as “Heavenly Bear”! Mystique?
WHAT DOES ONE MEASURE THE PRESSURE IN?
Most compressors have a scale marked in bars or atmospheres (kg/cm²). They are very close units: 1kg/cm² = 0,98bar . In addition, so called psi (pounds per square inch) is often used. Remember: 1 kg/cm² = 14.2 psi. If your car’s manual recommends a pressure measured in psi (say, 31 or 33), you may not convert one unit to another, but simply use a pressure gauge with an appropriate scale.
Methodology and Criteria
Our compressors had to inflate the tire with the size of 215/60 R17 – such tires are installed on many popular nowadays medium-sized crossovers. For the comparative analysis, we took two reference points – the pressure inside a wheel is 2,2 and 4,0 bars. The first value is the most common. And any compressor is obliged to inflate a tire to such pressure. The pressure of 4.0 bars allows you to put a tire on the so-called Hump – the ring projections along the edges of the wheel, which fix the tire and prevent its depressurization.
In addition, pumping up to 4.0 bar, we will test the compressors resistance to overheating during prolonged work (for example, when you want to inflate a pair of wheels, deflated “to zero”). Small compressors don’t like this mode very much, and we decided to evaluate them under harsh conditions. The time required to reach both milestones was measured with an electronic stopwatch. The supply voltage of 14 V was taken from the laboratory source HY3030E, from which we also determined the current consumption for each item. The accuracy of the standard pressure gauges was checked using the Intercomp reference device. At the same time we evaluated the usability of the products and the completeness of delivery.
As usual, the contestants were arranged alphabetically in our photo gallery. Not all of them made it to the finish line! Three compressors shamefully burnt out, and the fourth simply did not cope with their task.
The product Autostop AC-19 lived up to its name, stopping on its own. And it was not the plastic body which burned down, but… the hose.
The product Autostop AC-19 lived up to its name, stopping on its own. And it was not the plastic body which burned down, but… the hose.
Skybear Art. 212010 did not burn out, it just did not pump. The cause was a bad valve that turned the compressor into the mythological Sisyphus.
Skybear Art. 212010 did not burn out, it just did not pump. The cause was a bad valve that turned the compressor into the mythological Sisyphus.
Kölner KCO 12/19 distinguished by a bad plastic, which melted during the first attempt to inflate the wheel.
Kölner KCO 12/19 distinguished by a bad plastic, which melted during the first attempt to inflate the wheel.
OUR TIPS
- Almost all built in pressure gauges overestimate the measured pressure. Therefore, when working, try to inflate the tire with a reserve, and the final pressure value set by bleeding the air, using a proven pressure gauge.
- When choosing a compressor, pay attention to the location of the pressure gauge. It is desirable that it was built into the body, and not look out. This will save the device from breakage in case of an accidental fall.
- At long work the compressor can get very hot (the hand is hot). Therefore, it is better not to put it immediately in a case after work – let it cool down a little. Most likely it will not reach the fire, but it is not worth the risk.
- The compressor output hose is the most heated during operation – be careful.
- Pay attention to the total length of hose and wire. It should be so long that the outlet fitting can easily reach the far wheel. Too short a hose is inconvenient: If the valve is on top of the big wheel, the compressor will hang in the air.
- Small and lightweight compressors make an unpleasant high-pitched squeal, while more massive compressors make a low-frequency bass hum. Nerves of the neighbors when pumping tires in the yard of an apartment building will give up faster from a high-frequency source.
So which one to choose?
Winnie the Pooh chose between blue and green balls. Our task is more complicated: four compressors frankly failed, but eight of them passed the test! Of the survivors, we liked the AirLine X1 CA-030-14S and Heyner Art. 235000. The first one has good response time and an accurate gauge. The second one won over with its compactness and “cool” approach to the job. And both worked extremely well – there is a feeling of reliability.
Approximate price 670 rubles.
Declared power 96 W
Claimed pressure 5 bars
Claimed capacity 18 l/min
Claimed continuous run time of 15 min (cooling: 30 min)
Hose length 490mm
Hose length 2650 mm
On/off switch on the chassis yes
Weight without adapters 760 g
One of the cheapest products in our selection. The tip of the nozzle. The set includes three adapters. No fuse. The plug is ugly. Current consumption is from 5,4 to 6,2 A. Rattles when working. The pressure gauge is bad: 2.8 bar instead of 2.2. The first benchmark (2.2 bar) was passed by the compressor in 8 minutes. But after 11 minutes… the hose burned out. The cause turned out to be a design flaw: the hoses hid the hottest part inside the case with poor ventilation.
The approximate price is 1300 roubles.
Declared power 105 W
Claimed pressure 10 bars
Claimed capacity 28 l/min
Claimed continuous run time of 25 min
Hose length 720 mm
Wire length 2700 mm
On/off switch on the chassis yes
Weight without adapters 1550 g
There is a purse, although it is cramped. The tip is screw-on. Adapters are provided (except for the bicycle one). The plug is without fuse. Current consumption is from 10,6 to 11,4 A. Pumps very well: after 3 min and 30 sec the pressure grew to 2.2 bar, and after 8 min and 25 sec to 4.0 bar. The pressure gauge readings, as usual, are rather high, almost by 0.4 bar.
Not bad on the whole.
Approximate price 1750 rubles.
Claimed power 150 W
Claimed pressure 10 bars
Claimed capacity 35 l/min
Claimed continuous run time of 20 min (cooling: 20 min)
Hose length 1000 mm
Hose length 2800 mm
On/off switch on the chassis yes
Weight without adapters 2050 g
The kit includes a bag, four adapters plus a fifth to connect to the battery. The tip is screw-on. Comes with a fuse in the plug. Consumption current is 9.8 to 10.0A. The compressor reached 2.2 bar very fast, in 3 minutes and 20 seconds, and up to 4.0 bar in eight minutes! Manometer readings are overestimated, but against the background of other positive qualities, this can be forgiven.
Worthy workhorse
Approximate price 1250 rbl.
Claimed power n.a.
Declared pressure 7 bars
Claimed flow rate 30 lpm
Claimed continuous run time of 20 min
Hose length 650mm
Hose length 2800 mm
On/off switch on the chassis yes
Weight without adapters 1370 g
The tip is screw-on. The kit includes one adapter. No fuse in the plug. Current consumption is 8.3 to 8.8 A. Pressure gauge is perfectly accurate! There is practically no vibration in operation. Compressor reached 2.2 bar in 4 mins 4 secs, and 4.0 bar in ten minutes.
I like it very much.
Approximate price 910 rubles.
Declared power 96 W
Declared pressure 17 bar
Claimed flow rate 14 l/min
Declared continuous run time n.a.
Hose length 500 mm
Line length 2900 mm
Presence of switch on the body no
Weight without adapters 590 g
The instruction does not recommend using the product while driving… It’s funny. The tip is screw-on. Included – three adapters. Current consumption – from 3.5 to 5.7 A. It’s making a lot of noise. Took twelve minutes to get 2.2 bar and twenty minutes to get 4.0 bar. Pressure gauge reading was overestimated by about 0.2 bar.
Unremarkable compressor.
Approximate price 1800 rubles.
Claimed power 120 watts
Declared pressure 7 bars
Claimed capacity 25 l/min
Claimed continuous run time 10 min (cooling: 10 min)
Hose length 930 mm
Hose length 2680 mm
On/off switch on the chassis yes
Weight without adapters 1390 g
There are three adapters and a detachable hose, a flashlight is provided. The tip is screw-on. Current consumption is about 8.5 A. Manometer reading is very high. It took a long time to inflate the wheel: it reached 2.2 bar in six minutes, and 4.0 bar in seven minutes. We expected more from a device with a fairly high current consumption.
Not the best variant
Approximate price 1200 rubles.
Declared power 100 W
Declared pressure 7 bars
Claimed capacity 12 l/min
Continuous running time claimed 8 min
Hose length 380 mm
Wire length 3000 mm
On/off switch on the chassis yes
Weight without adapters 690 g
The inscription on the box, promising pressure as much as 21 bar – against the passport 7 bar, is one of the minor punctures. But other than that, I liked the product very much. The tip is a union tip. Four adapters are included, including the bicycle one. The plug has a built-in fuse. Current consumption is 3.7 to 7.0 amps. Pumps up to 2.2 bar in seven minutes and up to 4.0 bar in sixteen minutes. The body is almost cold on the outside; only the hose is warm. The pressure gauge is wrong, giving slightly too high reading.
It is an excellent gift for those who like small tools.
Approximate price 1620 rubles.
Claimed power n.a.
Declared pressure 7 bars
Claimed flow rate 30 lpm
Claimed continuous run time of 30 min
Hose length 960 mm
Wire length 1800 mm
On/off switch on the chassis yes
Weight without adapters 1490 g
Includes pouch and adapter set. The tip is screw-on. No fuse in the plug. Current consumption is from 8.7 to 8.9A. Pressure gauge reading is too high by about 0.2 bar. The device pumps with confidence: in 4 min and 20 sec it gave 2.2 bar pressure, in 10 min and 20 sec it gave 4.0 bar.
Approximate price 600 rubles.
Claimed power n.a.
Declared pressure 4 bar
Claimed flow rate 15 l/min
Claimed continuous run time 10 min (cooling: 30 min)
Hose length 440mm
Hose length 2800 mm
Presence of switch on the body no
Weight without adapters 560 g
The lowest price in our sample was alarming at once, and not in vain. The yellow “chicken” was jumping around on the floor actively, making a frightening noise. The pressure gauge with a fine scale tried to show something at first, but at about one and a half bars it suspiciously deviated aside and died… It melted! By the way, the current consumption was not excessive – only 5.3 A. The result is clear: the “chicken” was removed from the road for being unfit for work.
Approximate price 1800 rubles.
Declared power 140 W
Declared pressure 7 bars
Claimed flow rate 30 lpm
Claimed continuous run time of 30 min (cooling: 10-15 min)
Hose length 945 mm
Line length 2950 mm
On/off switch on the chassis yes
Weight without adapters 1465 g
The kit includes a bag, four adapters, spare 15A fuse. The manual says that the current consumption is not less than 23A. Where can you get it in a car socket? The real figure is half as much, but also quite high: from 11.5 to 12.0 A. When connected in some cars the fuse can blow. Makes a noble sound when working. The pressure gauge is very accurate – this is a rarity. Works confidently: pumping to 2.2 bar took 3 min 50 s, and to 4.0 bar only 9 min 11 s. It is a pity that the location of the pressure gauge does not protect it from breakage if the compressor is accidentally dropped. And the hose will always break when storing.
Works great, but is not for everyone.
The approximate price of 1050 rubles.
Claimed power n.a.
Declared pressure 20 bar
Claimed power output n.a.
Claimed continuous run time 16 min
Hose length 440mm
Hose length 2650 mm
Presence of switch on the body no
Weight without adapters 490 g
The “German” didn’t work right from the start. Consuming a current of 4.6 A for ten minutes, the compressor barely pumped pressure of 0.75 bar. It did not go any higher, so we decided to stop the tortures. Having disassembled the product, we found out that the valve was letting out part of the air. Let us also note a strange pressure gauge scale: two is almost next to zero. On such background there is no sense to speak about accessories and ergonomics. Good thing that there was no fire.
We hope, that only we got a defective exemplar.
The approximate price is 1100 rubles.
Claimed power n.a.
Declared pressure 4 bar
Claimed capacity 35 l/min
Declared continuous run time 5-15 min
Hose length 830 mm
Line length 2550 mm
On/off switch on the chassis yes
Weight without adapters 1200 g
The Chinese device was naughty at once. Having started with a nasty sound and exceeding the pressure 1.5 times higher than the real one, it began to increase the current consumption. It took 5 minutes and 20 seconds to reach 2.2 bar. But after another couple of minutes, bringing the appetite up to 15 amps, the Tornado emitted smoke and died in convulsions, filling the entire floor of the building with the smell of burning.
Blow: How to choose the right auto compressor?
If you travel by car or just frequently drive long distances and your tires are not of the RunFlat family, you probably already have an electric compressor pump living in your trunk. Or at least added to your “wish list”. Let’s see what should be inside the right compressor, how to use it, and how to get the most out of its possession.
How does a compressor work?
Penny compressors are a great example of wasted money. They come in a variety of sometimes very fancy designs, have a built-in flashlight, an emergency flasher and even a radio, may have a self-contained battery, a display and even an automatic shutoff at a preset pressure. But inside most of them lies the same mechanism: a low-powered electric motor, more suitable for children’s toys, through a speed-reducing plastic gear, connected to the crank mechanism, which drives the piston in the cylinder.
In this, so to speak, “mechanism” literally everything is done wrong – every element! Piston, cylinder, piston rings, bearings, heat removal, gauge with a wild error – everything is designed for rare applications (and even in warm weather). Otherwise the wear and tear of the mechanism becomes absolutely obscene, air pressure falls down drastically, but in excess there is a rattle and clatter…
The practice of the best manufacturers of automobile compressors showed that the piston must be with dry cuff from fluoroplastic variety – plastic with the lowest coefficient of sliding friction, and the cylinder must be solid aluminum with massive walls finned outside. Only this configuration allows a long service life without wear and pressure loss. But it does not occur very often.
As a rule, cheap compressors have a bare steel tube cylinder, and even if it looks aluminum with a ribbed radiator, it is only an external decoration that has very poor thermal contact with the cylinder.
The piston of shoddy pumps is necessarily thickly lubricated. And this is very bad, because it is the grease that provides compression and sliding, and when the oil escapes inside your tires (which happens quickly enough), the compressor immediately breaks the cylinder-piston group, sharply reduces the already poor performance, and the sound of work becomes unbearable. In a proper pump, the size of the engine is comparable to the size of a modern geared starter. How else could a thick shaft, powerful windings, magnets and solid support bearings fit in? The high capacity cylinder generates a lot of heat, which is effectively dissipated by the massive aluminum radiator, which is made as one unit with the cylinder.
The “correct” pump has a heavy duty connecting rod ball bearing. The disposable one doesn’t have one at all, and the metal rubs against the metal there.
Another sign of cheap disposable pumps is the lever tip. The drawback is not the type of nozzle, but rather the design. Threaded nozzles have 2-3 times more air loss when disconnecting than lever-operated nozzles (sleeved, crimped). But the disadvantage of lever-operated nozzles is the wear of the seal (crimp). It is usually made of rubber and the nipple thread is made of metal, and the thread itself is often sharp and acts as a saw on the seal if it does not comply with GOST. If you also take into account that in winter the rubber is hardening, the wear of the sleeves is very fast. But for small-diameter wheels, sleeves are preferable because they allow you to change the airflow by 90 degrees: good compressors often use sleeves of high quality .
Berkut R14 and R17
To demonstrate the proper reliable electric pumps, we took two models of one of the best domestic brands – “Berkut”. In fact, in the comparative photo above is just a model of R17. Hardly someone will reproach us in the annoying or incorrect “advertising”, because high reliability and durability of compressors of this brand for many years are known not only to thousands of ordinary Russian car owners, but also serious sportsman-jumper, and fans of pneumatic suspension, and builders signal pneumosystems, which make machines “steam locomotives”.
Berkut lineup is wide but we decided not to go deep into the questions of extreme, sports and semi-professional use, so we took R14 and R17 models, one of the most popular among the owners of passenger sedans and hatchbacks, as well as differently shaped crossovers.
The Berkut R14 is a compact, very quiet compressor with low vibration. It connects to the cigarette lighter, has a built-in LED flashlight for pumping the wheels at night and at dusk, precision pressure gauge, screw connector to the nipple with minimal air loss when turned off, is equipped with a convenient and very durable pouch.
Despite its compact size, the R14 is not only capable of inflating small 14″ wheels, as you might mistakenly think! The compressor is built according to the criteria of a good compressor as mentioned above. It has an aluminum cylinder, an oil-free piston and a powerful electric motor. With pressures up to 8 atmospheres, the unit can handle the large wheels of a large sedan or SUV very well.
Berkut R17 is a compressor for real active use. With it, you can safely go off-road in a crossover or small SUV with MT tires, inflate sets of seasonal tires from scratch, pump boats and much more. This high-performance pump, with a 40-minute continuous run time, develops 12 atmospheres of pressure with an even more powerful motor and more advanced aluminum cylinder cooling.
It connects directly to the battery terminals and has a handy 7-meter twisted hose with a screw fitting, an accurate gauge, and a convenient deflation valve that allows you to bleed off excess pressure when needed. Like everything in the Berkut line, this model comes in a sturdy, heavy-duty cordura cloth bag.
Tire Pressure: Controlling and Adjusting
“…I lie under the “Moskvich” with an oil syringe in my hands and gradually transfer the contents of the syringe both into the oil caps and onto my physiognomy. It’s hot and stuffy under the car, and the underside is covered with a thick layer of dried mud…”
A. and B. Strugatsky. “Monday Starts on Saturday”.
Modern car owners are not like their fathers and grandfathers. Not only have we forgotten what kingpins are, but we safely ignore daily oil level checks, tire pressure checks, and much more. Certainly, there is no need to check a lot of parameters of a modern car every day, but it is worth doing it at least once a week: less money will be spent for repair of timely discovered defects, and your expensive tires will work longer.
Can you detect pressure drop of 0,2 atmospheres by eye, for instance? Hardly… And such, it would seem, insignificant leakage will not be in your favor at sudden high-speed maneuver, and at the same time it will noticeably accelerate tread wear and increase consumption. Decrease of pressure by 10 % from the norm decreases car running time by 20 %. And, in spite of the fact that formally the coasting is coasting on inertia, its decrease influences the increase of fuel consumption in any mode of driving.
My point is that it is rather easy to control vehicle behavior on road by regulation of pressure in tires, having a qualitative compressor with a precise pressure gauge. Of course, you will not be able to radically increase the handling or passability of the car, but adjusting the pressure in accordance with road conditions will always be noticeable. In sand, dirt, wet grass, you can lower tires up to 1.5-1.3 atmospheres, increasing the contact patch area with a surface, on high-speed runs on good roads – to raise the pressure by about 0.1-0.2 atmospheres of the norm. If the interior is fully loaded with passengers and luggage, the pressure can be increased even more, by 0,3-0,4 atmospheres from the norm.
The frail non-breed electric pumps pump a completely deflated wheel for a very long time, with each minute more and more overheating and losing performance. Let’s see how the right compressors do it.
We take three wheels (R17 235/65, R15 185/60 and R13 175/70), lower them to zero and inflate them to 2.5, 2.0 and 1.8 points respectively. We test the “Berkut R17” connected to the battery terminals with the engine running and with the engine stopped, and less current consuming “Berkut R14” having a plug to the cigarette lighter – only with the engine stopped. The second is acceptable as the compressor is smaller, but we recommend to use the compressor with the started engine: it not only saves from discharging of the battery but also provides easier start of the compressor under loading and faster inflation and more careful treatment of car circuits due to decrease of current.
The result, I must say, is excellent.
By the way, if your pump has a large margin of safety and does not belong to the category of “auchan-compressors”, which need to save in it tiny crumbs of life, it will perfectly cope with the work with a much larger volume than the wheel. For example, with Berkut R17 it is not difficult to switch “from wheels to oars” by inflating your boat with it. However, you will need to have an adapter from the tire “nipple” to the boat valve like Ceredi, Bravo or another, used on your boat. This adapter can be purchased or you can make it yourself by buying a boat connector and a tire “nipple” separately. You need to unscrew the nipple from the latter, cut the rubber thickening with a knife and insert it tightly into the nipple.
Inflation speed, of course, is not high (for 280th two-cylinder boat it took us 23 minutes). Yes, the compressor is still designed to deliver pressure, not cubic capacity. But there is usually no hurry in the nature, and R17 rattles quietly and undisturbed and does not need a running motor, as the current consumption is very small when working on a large volume. So you can handle a boat, too, if you want to.
A cheap compressor, on the other hand, will probably spend its whole life on this job. Life, it should be said, is short and hard.
