Your thoughts guys...

 

http://www.ebay.co.uk/itm/4PCS-Car-Tire-Tyre-Pressure-Monitor-Valve-Stem-Cap-Sensor-LED-Indicator-New-/171098873076?pt=UK_Cars_parts_Vehicles_Wheels_tyres_trims_Valve_Caps_ET&hash=item27d6499cf4

 

 

Memory says that, when these first came out, they were implicated in a number of sudden motorway speed deflations.

Although they are a nice idea in theory, I tried some of these on a previous car and found them worse than useless.

 

Firstly in order to detect the pressure they hold the tyre valve open all the time, but the caps themselves don't seal properly, so they slowly let your tyres down.

 

Also, they seem insensitive to even fairly large pressure drops. Mine were still showing fully green when the tyres were 5-10 psi below what they were supposed to be. So not only do they let your tyres down, they don't even warn you that they've let your tyres down!

 

My set went in the bin after less than a month.

Check pressures weekly and each day have a quick look at the tyres as you walk up to the car in the morning. I find this method means I soon notice a slow puncture or something iffy. 

thanks for the feedback guys

You would be better off with one of these:

 

http://www.ebay.co.uk/itm/Universal-Fit-Tyre-Pressure-Monitoring-System-for-Pressure-Temperature-TMPS-/321161876963