Viair portable 12 V tire inflator

What it is good at

• Adding air at home rather than hunting for a working pump
• Running from the 12 V socket so there is no battery to keep charged
• Reaching all four wheels with the hose supplied, including a spare in the trunk

Check before you buy

• Duty cycle: how many minutes it runs before it must cool, which decides how many tyres in one go
• The gauge — dial or digital — and whether it can be read while the pump is running
• Hose length and the connector against your valve stems, including any valve extensions on the wheels

Who it is not for

Anyone who wants to run air tools or spray a panel. Those need a compressor with a tank rather than a tyre inflator.

Tyre pressure is the cheapest maintenance there is, and the reason people skip it is the queue at the air line. A 12 V inflator removes that excuse: it lives in the trunk and runs from the socket you already have.

Look at the duty cycle rather than at the quoted maximum pressure, because a pump that needs ten minutes of cooling between tyres is not much faster than driving to a station. A screw-on connector holds better than a lever clamp on some valve stems, and one that reads while running saves you a second pass with a separate gauge.