Steelmate TP-70 Tyre Pressure Monitor

All new cars have to be fitted with tyre pressure monitors from this month, but you don’t need to splash out on a showroom-fresh model to benefit, as the Steelmate TP-70 is an aftermarket system that works on your existing car.

All you have to do is unscrew your valve caps, and replace them with the four sensors included in the kit. These are a little bulkier than your standard valve caps, but they’re clearly labelled so are easy to fit – you can be up and running in five minutes, with no need to remove the tyres, like on rival systems.

Each sensor is powered by a watch battery, which should last up to four years. They send data wirelessly to a tiny display on top of a 12-volt plug. This makes the plug bulky in the socket – nothing was obstructing the input in our Ford C-MAX test car, but if you have 12V ports inside an armrest, you won’t get on with the TP-70.

Lights in each corner of the display refer to the tyre in each corner of the car, and by clicking the button on the device, you can toggle through these, to see what reading they show. We’d already checked the pressures using a trusted gauge, and the system gave the same readings for each tyre. It also highlighted a slow leak on one of our tyres. For £89.98, this is a time-saving bit of kit.