As has been said red diesel will not harm a DERV (Diesel Engined Road Vehicle) BUT the dye in it WILL stain the internals of the IC system. If HMRC find any trace of that die in a DERV they have the powers to seize the vehicle as well as heavily fine the perpetrator - and they WILL do it!
As to why fuel is so dear, the oil sheiks are the last people to blame. They are so filthy rich because the sell so much of the stuff. Here are the people more to blame: Oil companies, oil speculators, Governments (tax).
t
June 2008