Rover 75 / MG ZT PRT Thermostat -1.8 K Series - PEM100990 / PEL500110 (inc Turbo)
If your temperature doesn't quite reach half-way or have overheating problems you can't pinpoint, you probably have a stuck thermostat.
This is a quality replacement for the PRT thermostat, and will restore normal functionality. This is an 82 degree item.
The PRT thermostat was added to later cars as a measure to combat HGF - make sure you have one fitted to your car before ordering. You'll see it located within the rubber cooling pipes in your engine bay.
Originally PEM100990 referred to the 88 degree item - since these are 82 degrees, I've also added the 82 degree part number (PEL500110) as this is cross-compatible.