Portable 12V compressors are small air compressors which run directly from a car battery. They're traditionally used by four-wheel drive enthusiasts to adjust tyre pressures.
A 12V compressor may seem unnecessary for those who rarely venture off paved roads, but there are a number of reasons why it could be a handy item to keep in the boot of your sedan, hatchback or convertible.
Serious four-wheel drivers routinely change tyre pressures to adapt to differing driving surfaces. While the manufacturer’s recommended tyre pressures are fine for the highway, when it’s time to leave the tarmac these pressures are generally too high for off-road use. Deflating tyres for driving on sand, mud or snow increases the surface area in contact with the terrain or “contact patch”, thus improving traction. However, when the off-road fun is over, tyres must be re-inflated to ensure safe handling, and minimise damage through wear and overheating.
Regardless of which type of vehicle you drive, owning a 12V compressor might make sense. Tyre pressures can be checked and maintained anywhere, anytime. Ensuring correct tyre pressures is one of the simplest and most beneficial things you can do as a motorist. It can improve your car’s handling, safety and fuel economy while ensuring the maximum lifespan of your tyres.
- ARB CKMP12
- Bushranger Black Max Compressor 55X12
- Dr Air Pro Flow AC495
- Dr Air Typhoon AC402
- Mean Mother Adventurer II MMACA2
- Repco RAC085
- TJM 013TJMCOMP
Our tester, Peter Horvath, times how long it takes to inflate one 4WD tyre from 0 to 40, and four from 20 to 40 psi. He also measures noise and evaluates each model for ease of use.
For more information about car accessories, see Cars.