QUOTE(GT4 BOOSTER @ Oct 1 2007, 06:06 PM)

you need to register with customs and excise , keep a record for 6 years , if you use over 2500 ltrs a year you pay duty on whatever over the 2500 .
a ratio of 70% derv 30 % veg oil is ok for this time of year . use less oil as the winter draws in.
carry a spare fuel filter and also make sure you can change the fuel filter by hand , not too tight
better still, drain off the fuel in the tank , there's a drain bung in the tank 17mm . flush it out with 5 litres of fresh derv , this flushes any crap out of the tank , oil sticks to tank particles and drags it into the filter , clogging it .
use redex on a regular basis too , cooking oil can glaze the pump and injectors . if you do experiance running problems , get back to neat derv asap .
you can also add a pint of unleaded in the winter , this thins the oil and also adds a bit more flammable mix to ease starting and running .