Much appreciate the advice chaps, not really keen on red as I the edon't want the stress. Am interested in the long-term effects of running bio-diesel on a ren traffic if anyones been using it for some time.....
5+ years with absolutely no problems what so ever for a Transit Connect.
All you need to worry about is changing the fuel filter once or maybe twice to start with as bio diesel clears all the muck out the fuel pipes which then clogs up the filter. It doesn't damage the engine, it just starves it of fuel when you accelerate.
It's a pretty simple job to change the fuel filter.
Aslo, check with the manufacturer of your van first to see if it's ok to use bio diesel. I'm certain that all Renault diesel engines are ok for bio diesel but check anyway.
Originally the diesel engine was made to run peanut oil.
Never, and I stress the 'NEVER', try to use untreated cooking oil or any untreated oil as fuel. It'll coke up your engine in no time.
With bio diesel, you'll never ever fail the emissions test for an MOT.