Right so I now have a cheap infrared laser thermometer to do the "turnip test" :)
2001 TD4 72,000 with original VCU , 4 matched tyre all tread within 1mm front/back .
journey from work 7 miles mostly at 30mph with traffic
outside temp - 6.2 c
IRD - 52 c
Rear diff-16c ? ( wet so...