Warm up time on a 4.0 TDI

[sutherland]

After years of driving petrol Audi V8s, I recently switched to a 4.0 TDI. So far it's been a good experience, but I am wondering how long these engines normally take to war up? Yesterday, I had to drive for about 10 miles and 17 minutes before the guage reached 90C whereas my petrol A8s were at normal temperature fairly quickly even when it is freezing outside. I also do not recall other diesel cars taking such a long time to warm up.

Is this normal behaviour for a 4.0 TDI or do I have a lazy thermostat or something?