babyRR.com - The Range Rover Evoque Forum

The Tyre Pressure Monitoring option (TPMS) costs £405 and is very basic in what it does. It simply warns you when a tyre is significantly under-pressure but for the rest of the time, it is invisible. There is nothing to see, touch or get excited about what your £405 has bought you.

Audi provide the same function in the Q3 for £85. What's missing is a graphic on the driver display of the actual pressures in each of the 4 tyres which vary as they heat up, for example, but which also allows you to detect a slow puncture before it has done any harm. This is what the systems in Porsches and Mercedes do, for about the SAME cost as the LR system. It's very useful to be able to see the actual tyre pressures while driving. Hands up all those who don't check their tyre pressures every week?

I wrote to LR - Mike Cross actually - to complain about the low level of function and I had a helpful reply from LR External Communications. First, they bothered to reply and the author had spoken to engineering who confirmed the function is as described but it's hoped to improve on it in the future (Later Model Years? Software Refresh?). He also said he would pass my comments about the cost - uncompetitive, poor value for money compared to Audi, Porsche, Mercedes - on to the department who deal with these things.

So, helpful in the sense that they have taken my comments seriously, though unhelpful to me in that the TPMS does not provide the function I expect for the cost and I'm now going to remove it from my build.

Well done Mark - unfortunately it's too late to remove it from my car's spec as it is build early next week

This basic system was £35 on the Scirocco when we bought it, but unfortunatly forgot to tick the order box.

This basic system was £35 on the Scirocco when we bought it, but unfortunatly forgot to tick the box,
however found out it was a function already built into the electronics system and was simply a process of enabling it with VAG software otherwise known as VCDS- basically most new cars are hardware configured to allow ease of build and then the software is switched on or off depending on different markets and if a customer is willing to pay for it as an option. Its like everything nowadays -somethings you are just not ment to know about.

The basic system uses the wheel rotation sensors - which are there to detect wheel lockup for ABS - to detect a change in relative wheel rotation speeds which would imply low pressure in a tyre. A flat tyre has a small rolling radius and therefore rotates faster. The software monitoring the wheel rotation would have to filter out short term variations - wheel slip, cornering - and also a static difference due to tyre wear, asymmetric loading and unequal but still within tolerance inflation pressures. As Quattroman says, enabling this is just an option used by say the ABS Control Unit.

The better system - which is used by LR - has a sensor in the tyre valve which transmits to an aerial in the wheel arch. The data of actual pressure (and possibly temperature) is then displayed to the driver and a warning issued when the pressure is too low. The sensors are battery powered and intelligent enough to only transmit when there is a change to conserve power.

So LR are using the right hardware but someone has been asleep on the job when the software was spec'd and developed. I had hoped that there could be a software upgrade but I'm not going to risk it.

I've now emailed the dealer and told him to delete the option unless he can supply it for the same price Audi charge for the same function, £85. I don't think he will!