During fuel strike of 2001? I used tescos sunflower oil in my landrover with tdi engine , had to thin it a bit with 28sec heating oil mainly to ensure good flow through the filters, lost a little power , stunk like a chip pan fire but never missed a days work and covered 150 miles per day throughout strike and never queued at fuel pumps once ! not sure whether common rail engines would cope as well as conventional diesels. Cant see any reason why not though, a diesel will near enough burn anything injectable. Many years ago "Tomorrows world" did a feature on South Africa and showed how tractors were running on straight sunflower oil there with only a loss of around 5% power. Also sunflower oil is a far better pump lubricant than low sulphur diesel, a small proportion added to every tank of fuel would certainly help pump and injector longevity.