With the recent cold weather, I've noticed that the water temperature on my car is very slow to warm up. So with an ambient temperature of -1 degrees it took 10 minutes/6 miles of normal driving for the temperature gauge to get to the normal temperature. Is this normal given the cold weather or slow enough to indicate a thermostat issue? If I have a thermostat issue, is this something that "must" be fixed or just one of those things you can live with and just accept a bit of reduced fuel economy at the start of every journey?

Of course the cold weather means it isn't as quick at warming up, but it depends how you drive, if your tickling the throttle and just cruising along it will take about 3-6 miles to warm up. But if you do a few full throttle moments, puling away from lights, or going down slip roads etc, then it will be at 90 degrees in 5 mins. (or at least thats how the vrs behaves)

If it was a thermostat issue it would never warm up, or be constantly hot, depending on if it stuck open or closed. But if its gets worse and seems more like a thermostat problem i would say given the cold weather i would fix it sooner rather than later, because spark plugs, oil, etc is designed to run at certain temps and if the engine is running too cold it wont be too smooth and will start stuttering in cold weather. Will also make things like your idle control valve work harder.

Sounds normal. My VRS is warm in 3 miles in warmish weather, but takes 6 miles in cold weather to reach proper temperature. Diesels do take a while longer than petrol engines though.

Nice colour that! (same as mine)

Sounds normal to me too. I've just sorted this out on our 1.4 mpi.

Booked in next week for the rest of our 'teething' issues and then hopefully we can enjoy the car.

But if you do a few full throttle moments, puling away from lights, or going down slip roads etc, then it will be at 90 degrees in 5 mins. (or at least thats how the vrs behaves)

That style of driving should NEVER be recommended though.

Premature engine wear is caused by driving a car hard before the oil has fully warmed up.

Providing the car does fully warm up (as you say it does after around 6 miles) then there seems to be nothing wrong with the thermostat.