my suggestions are
1; always keep your reciept (i use c/card so i have records)
2; wherever possible buy from a major servo with high turnover
3; use fuel doctor or equivilent in every tank
4;dont store diesel for long periods,even in fuel tank
5; fitting a 2nd filter is a good idea if your travelling in remote areas
6;if you have dirty fuel issues keep a sample,notify insurance company immediatly,or if not covered with insurance notify servo immediatly as they are liable,but dont give them all the sample,keep a bit in case they "loose it"
cheers
