Hi IAN.
If its really cold i will just top the tank up with more diesel this time of year no problem 50/50
I change the fuel filter twice a year.
Van is a 2001 pre common rail 3.5 dti
Well 1000 miles went 9000 miles ago no blow ups yet!!!!!
Not used it in motorhome yet i use all my allowance up in van. Yes its legal think its up to 12000 miles but how they work it out i dont know.
Cheers Tony