13-06-2013, 11:34 PM
In a diesel engine, it's normal for a small amount of fuel to contaminate the sump oil. With mineral diesel, this isn't much of a problem, but with veg it can be. Many people advise halving the oil change interval if running veg. Personally I change the oil on my 406 every 3,000. With these very short intervals, you don't need expensive oil. I also bulk buy filters and stock up on oil when I see special offers (currently running Halfords semi-syth at £10 for 4 litres). £12 or £15 every 3,000 miles is really not a significant cost.