The RAC635 is a multi-award winner. It won Auto Express’ Best Buy Award in 2014, and Professional Driver magazine’s Best Buy for mini air compressors. The experts agree: this is the best mini digital air compressor there is. ALL THE EXTRAS. Includes LED light with three settings (bright white to illuminate, flashing white for attention and flashing red for SOS), three piece valve set for bikes and balls, and case for tidy storage

It’s noisy, dishing out 77dB in operation. And the pressure gauge can be difficult to read since, because it goes up to 250psi, that crucial 0 to 60psi zone is crammed into the first quarter of the dial. However, it pumped up our test tyre from 20 to 30psi in just under two-and-a-half minutes, with no fuss or faff. It’s a shame that the supplied accessories are so basic – just a ball inflator and two adaptors for inflatable toys – still, if you’re looking to spend as little as possible, then the Storm Force Mini does the job.There are a few extra attachments to allow the inflation of bicycle tyres, footballs or inflatables like dinghies or air beds. So if you’re outdoorsy then it’s a worthwhile thing to keep in the car even if you’re not too worried about your tyres. Build quality is sturdy - in our testing we dropped and bashed the unit and while it does have a few little scratches here and there it’s still in one very chunky piece. Should I buy one? Larger inflators include rechargeable batteries, which make them completely portable. These are a better option if you want to pump up, say, bicycle tyres, without having to wheel the bike next to your car. You may also need a larger inflator for tyres that need higher-than-average pressures, such as a larger van or campervan. What about extras? The pressure is usually shown in two formats: bar and psi. There are typically two sets of these. The lowest is for normal use, but you may well see another set of higher pressures for when the car is heavily loaded, increasing the weight that’s pushing down on the tyres. If you want to be equipped for every flat tyre eventuality, the VonHaus Cordless Tyre Inflator has you covered. It will run for up to ten minutes from the supplied 1.5A lithium-ion battery, but if you forget to charge it you can always switch to the bundled 12V adaptor, which comes with an unusually generous 3.5m cable. It has a small, but still readable, digital pressure meter. And you can just set your desired pressure, pull the trigger and let it go to work: it will stop when it reaches the right level.

SEE THE DIFFERENCE. Watch the video to see the RAC635 in action, and scroll down for more information on the award-winner The built in LED light makes inflating at night easier and safer, and can be set to SOS mode to attract attention or warn other motorists. Express delivery option to offshore, highlands and remote postcodes may take longer than the usual one working day. The surcharge may not apply to small items being sent via Royal mail or MyHermes etc... Where possible we will try our best to avoid courier service for surcharge areas. Plugging it in and connecting it to your car’s tyre valve is very easy and intuitive, although you might miss that torch function of the 635 if you’re attempting to do it on the side of a dark road. The three-metre power lead unwinds easily and is long enough for most purposes.As well as being capable of pumping up car tyres, this air compressor also comes with a handful of other adaptors to inflate bicycle tyres, inflatables and footballs. Should I buy one? Tyre pressures are typically between 30psi and 40psi (or 2 bar and 2.8 bar). How to test your tyre pressure EASY TO USE. Simple autostop feature allows you to preset the pressure you need, and it will automatically stop inflating once that pressure is reached. Accurate inflation, every time Each of the inflators tested here has a gauge that gives you an instant readout that lets you know whether the tyre needs pumping. To use them, simply remove the dust cap from the valve on the tyre and push the end of the air hose over it, before pressing or releasing any catch to clamp it in place. Petrol station tyre inflators have pressure gauges, too, but these aren’t always accurate so it’s best to test using your own equipment.

Size is probably the most important thing. The smallest inflators are around 20 x 20cm, so you can leave them in your car without losing too much luggage space. The best don’t skimp on the length of the power lead and air hose, which makes it easier to reach all four valves. Most can be preset to stop inflating when your tyre reaches the correct pressure. Once the tyre has reached the pre-selected pressure the system switches itself off and can be disconnected. Easy. If you need to use the compressor at night then it’s fitted with a torch, plus there is a flashing red light for signalling in an emergency and a valve for letting air out of a tyre if needed.

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DOUBLE AUTO EXPRESS WINNER. Trust the experts - Britain's most popular car magazine has chosen the RAC635 Tyre Inflator as their Best Buy twice - in 2014 and 2016. Proven to be the best there is FREE UK delivery applies to Zone A, UK Mainland England, Wales and Southern Scotland (Central Belt of Scotland) and Excludes surcharge post codes and areas.