Air Compressor Buyers Guide
Gear

Gear: Air Compressor Buyers Guide

One of those tools you should never travel without is a 12V DC compressor. Apart from the obvious tyre-inflation purpose, compressed air can be used to re-bead a tyre that’s come off the rim, aid in a puncture repair, pump an air mattress, engage air-locking differentials and (if you have an air receiver) even operate power tools.

The humble air compressor comes in a massive variety of shapes and sizes, from your cheap-as-chips Chinamade single piston unit to the high-output twin piston setups from premium brands. Prices vary massively, as does performance.

Depending on your application, an el-cheapo pump may be fine, but bear in mind that most of the cheaper units may take up to 10 minutes per tyre to inflate it from flat to the recommended road pressure. Cheap compressors will have a shorter lifespan than highquality units, and may not be capable of engaging an airlocking differential.

When considering air flow, it is worth knowing that the rated air flow for a compressor is measured from zero bar, but that the compressor’s air flow is reduced as the pressure in your tyre increases. The ability of a compressor to maintain high air flow despite increasing pressures is important.

Most manufacturers will state for how long, and at what pressure, their compressor can operate. A few compressors may even offer a 100% duty cycle, which means that they can run continuously for extended periods without the need to cool down.

Unfortunately, as with most things, performance comes at a price, so that compressors with longer duty cycles, higher flow rates and better warranties will be positioned towards the top of the price list.

For the purpose of our comparison, we’ve chosen a selection of locally-available air compressors based on their price segment. Have a look at the cheaper options if you use your compressor only once in a while, but at the more expensive options if you frequently have to inflate large 4x4 tyres. All the compressors in our comparison are portable units, although most have the necessary brackets for permanent fixture to your vehicle.


Consider These

Why do prices vary so widely? It’s not just about place of manufacture or the number of pistons; there are other specific things to look for when you are making a buying decision.

Sound

Cheap compressors are often built without much in the way of sound deadening, so can be extremely noisy, despite being only small. Start them up in the shop, so that you can find out whether your particular choice sounds like an antelope in the mating season before you decide to buy it.

Durability

More expensive compressors may have Nikasil-coated cylinder liners and carbon fibre piston rings as opposed to alloy cylinders and plastic rings. You just know which one will last the distance. Of course, the added durability of more exotic materials comes at a price.

Dimensions

If you’re hard-mounting your compressor in your engine bay, make sure that your compressor of choice actually fits. Many portable compressors come with a handy carry case that you can store inside your vehicle. One of the reasons that the ARB CKMTP12 twin-piston compressor is so expensive is its unique, compact design. Remember that the single-piston setups are considerably more compact than the twin-piston units.

Warranty

Cheap compressors will, more than likely, be less reliable than expensive ones. Companies that have faith in their product will generally offer a longer warranty. You need to have faith in the product, too – or risk being stuck in the middle of nowhere with a flat and no back-up hand pump.

Electrical connection

Some lower output/lower draw compressors may use a connector that plugs into your vehicle’s cigarette lighter. Check first that your cigarette lighter socket produces the amperage necessary for your compressor as, if it doesn’t, you’ll end up blowing fuses. Some of the outlets in the vehicle are designed to carry heavier loads: check first, and don’t just casually put in a fuse with a higher rating. A more popular and safer electrical connection is that of crocodile clips that connect directly to the battery terminals. (All of the compressors that we list here have direct connections to the battery.)

Flow rate

The amount of air a compressor can pump out is measured in litres per minute (LPM). This is one of the vital statistics. However, as pressure rises (and load increases), a pump’s flow rate will gradually lessen. Pumps with larger pistons, or twin-piston pumps, will naturally have a higher flow rate, but are more expensive and less compact. However, not all manufacturers disclose their flow rate under pressure. You’ll notice in the listed specifications that the more premium brands are happy to divulge their flow rate as pressures rise. Some other brands are less keen to give all the information – possibly a clue to inferior performance.

Duty cycle

The amount of time a pump can work before it needs to cool down is a critical issue for these always-on 12V compressors. A pump with a 50% duty cycle that pumps for only two minutes at a time before it shuts down, or overheats, would be almost useless in the real world. However, if it has a 50% duty cycle and can pump for 30 minutes, it will prove more useful. Some pumps (like the ARB Twin Piston) have a 100% duty cycle, which means that they can pump continuously without cooling down. Duty cycles are measured at 22°C; so, in hotter temperatures, the manufacturer’s claimed duty cycle may be reduced. Most compressors have a thermal cut-off switch that will temporarily shut down the compressor until it cools.

Current Draw

The more powerful your compressor, the more current it will draw, so that if your vehicle has a small battery, it would be advisable to idle your engine when using your compressor for extended periods such as when pumping four tyres. A compressor will use its maximum draw when it is working hardest at maximum pressure.


Pumping Test

Pumping Test

 

This was not an entirely fair test. On one side of the ring, the battered remains of a cheapie that had rattled off every casing, and the on-off switch, after being subjected to a year of hard work. This version was originally supplied with a cigarette-lighter plug, since modified to use crocodile clips. Like other single-piston units, we estimate it produces 36 litres/ minute of pumping power.

On the other side of the ring, a relatively new twin-piston unit from Off Grid, supplied with heavyduty cabling, a decent hose line and rated at 160l/minute.

Our real-world test involved pumping a BF Goodrich KO2 265/75 R16 tyre from zero bar (flat on the ground) to 2 bar. The result? Cheapie: 6 minutes 21 seconds. Off Grid dual head: 2 minutes 10 seconds. That’s three times faster, per tyre. And the key reason why you want a proper compressor in your toolkit when you travel.


Air Compressor Selection

To make your choice of compressor easier, we’ve split the field into three price categories. We have excluded the tiny air compressors that plug into cigarette-lighter sockets and often cost under R500, simply because we don’t deem them suitable for inflating 4x4 tyres repeatedly.

Premium R5000+

ARB CKMTP12 Twin Portable Compressor

Expect to pay: R7600

 

ARB CKMTP12 Twin Portable Compressor

 

 

Hose style: 6m hose
Pressure gauge: No
Battery connections: Crocodile Clips
Motor cooling: Air & fan cooled
Max current draw: 50A
Duty cycle: Continuous
Air flow (litres per min): 174.3l at 0 bar/131.7l at 2 bar
Recommended max pressure: 10.3 Bar
Weight: 12.5kg (estimated)
Length/Width/Height (mm): 190/480/340
Warranty: 2 years
Accessories supplied: Plastic case
Retailers: 4x4 Megaworld, Safari Centre


ARB CKMP12 High Output Portable

Expect to pay: R5000

 

ARB CKMP12 High Output Portable

 

 

Hose style: 6m hose
Pressure gauge: No
Battery connections: Crocodile Clips
Motor cooling: Air-cooled motor
Max current draw: 32 amps
Duty cycle: 30 minutes
Air flow (litres per min): 75.1l at 0 bar/61.6l at 2 bar
Recommended max pressure: 6.9 Bar
Weight: 3.3kg
Length/Width/Height (mm): 208/440/238
Warranty: 2 years
Accessories supplied: Plastic case, extra nozzles
Retailers: 4x4 Megaworld, Safari Centre

 

Value R2000 - R4999

Ironman Flomax 160 L/PM

Expect to pay: R3150

 

Ironman Flomax 160 L/PM

 

 

Hose style: 5m coiled hose
Pressure gauge: In-line
Battery connections: Crocodile clips (2m cord with battery terminals)
Motor cooling: Air-cooled motor
Max current draw: 45A
Duty cycle: 40 minutes
Air flow (litres per min): 160 at 0 Bar
Recommended max pressure: 10 Bar
Weight: 9kg
Length/Width/Height (mm): 330x230x140
Warranty: 3 years
Accessories supplied: Carry bag, pressure gauge, extra nozzles
Retailers: Ironman 4x4


T-Max 160 HD Compressor

Expect to pay: R3195

 

T-Max 160 HD Compressor

 

 

Hose style: Coiled hose
Pressure gauge: Inline analogue gauge
Battery connections: Crocodile clips
Motor cooling: Air-cooled motor
Max current draw: 45A
Duty cycle: N/a
Air flow (litres per min): 160l at 0 bar/70l at 2 bar
Recommended max pressure: 10 bar
Weight: 8.4kg
Length/Width/Height (mm): 340/155/225
Warranty: 1 year
Accessories supplied: Carry bag, pressure gauge, extra nozzles
Retailers: 4x4 Megaworld, Safari Centre


Ironman Flomax 72 L/PM

Expect to pay: R2095

 

Ironman Flomax 72 L/PM

 

 

Hose style: 5m coiled hose
Pressure gauge: Inline
Battery connections: Crocodile clips
Motor cooling: Air-cooled motor
Max current draw: 30A
Duty cycle: 40 minutes
Air flow (litres per min): 72 at 0 Bar
Recommended max pressure: 10 Bar
Weight: 5.2kg
Length/Width/Height (mm): 300 x 200 x 130
Warranty: 3 years
Accessories supplied: Carry bag, pressure gauge, extra nozzles
Retailers: Ironman 4x4

 

Budget -R2000

Off Grid 150LT Dual Head Compressor

Expect to pay: R1995

 

Off Grid 150LT Dual Head Compressor

 

 

Hose style: 5m Rubber hose
Pressure gauge: Inline Pressure gauge with PSI & kPa
Battery connections: 1.8m Heavy Duty Lead with 100Amp insulated battery clamps
Motor cooling: Air-cooled motor
Max current draw: 45A
Duty cycle: 35-40min
Air flow (litres per min): 150 litre / min
Recommended max pressure: 10 Bar
Weight: 5kg
Length/Width/Height (mm): 300 x 150 x 200
Warranty: 2 years
Accessories supplied: Carry Case, Inline pressure gauge, extra nozzles
Retailers: Safari Centre & TJM Equipped outlets


Opposite Lock 72L/PM Air Compressor

Expect to pay: R1995

 

Opposite Lock 72L/PM Air Compressor

 

 

Hose style: 5m coiled hose
Pressure gauge: In-line pressure gauge
Battery connections: Crocodile clamps
Motor cooling: Air-cooled motor
Max current draw: 30A
Duty cycle: 20/30 mins
Air flow (litres per min): 72l
Recommended max pressure: 10.3 Bar
Weight: 5kg
Length/Width/Height (mm): 280x 150x 200 (Bag)
Warranty: 2 years
Accessories supplied: Carry bag, pressure gauge, replacement fuses and crocodile clamps, extra nozzles
Retailers: Opposite Lock


Trailboss 160L/PM

Expect to pay: R1895

 

Trailboss 160L/PM

 

 

Hose style: 7m coiled hose
Pressure gauge: In-line analogue gauge
Battery connections: Crocodile clips
Motor cooling: Air-cooled motor
Max current draw: 45A
Duty cycle: 40 Minutes
Air flow (litres per min): 160 at 0 Bar
Recommended max pressure: 10 Bar
Weight: N/a
Length/Width/Height (mm): 360/150/240
Warranty: 6 months
Accessories supplied: Carry bag, pressure gauge, extra nozzles
Retailers:Outdoor Warehouse


Adendorff 160L/PM Air Compressor

Expect to pay: R1595

 

Adendorff 160L/PM Air Compressor

 

 

Hose style: 8m coiled hose
Pressure gauge: Inline analogue gauge
Battery connections: Crocodile clips
Motor cooling: Air-cooled motor
Max current draw: 45A
Duty cycle: N/a
Air flow (litres per min): 160 at 0 Bar
Recommended max pressure: 8 Bar
Weight: 9.5kg
Length/Width/Height (mm): 590/400/290
Warranty: 1 year
Accessories supplied: Carry bag, pressure gauge, extra nozzles
Retailers:Adendorff


T-max Portable Compressor 72L/PM

Expect to pay: R1495

 

T-max Portable Compressor 72L/PM

 

 

Hose style: Coiled hose
Pressure gauge: Inline analogue gauge
Battery connections: Crocodile clips
Motor cooling: Air-cooled motor
Max current draw: 30A
Duty cycle: 40 minutes
Air flow (litres per min): 72 at 0 Bar/50 at 2 Bar
Recommended max pressure: 10 bar
Weight: 5.2kg
Length/Width/Height (mm): 300/140/185
Warranty: 1 year
Accessories supplied: Carry bag, pressure gauge, extra nozzles
Retailers: 4x4 Megaworld


Trailboss 72L/PM

Expect to pay: R1395

 

Trailboss 72L/PM

 

 

Hose style: 5m coiled hose
Pressure gauge: Inline analogue gauge
Battery connections: Crocodile clips
Motor cooling: Air-cooled motor
Max current draw: 30A
Duty cycle: 40 minutes
Air flow (litres per min): 72 at 0 Bar
Recommended max pressure: N/a
Weight: N/a
Length/Width/Height (mm): 260/110/180
Warranty: 6 months
Accessories supplied: Carry bag, pressure gauge, extra nozzles
Retailers: Outdoor Warehouse

 
 

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