My brother in law is a fuel injection mechanic and we had this discussion a while back. He said basically what Blackhawk said - dilute diesel with jet fuel for the older low pressure injection systems [couldn't come up with a percentage though] but under no circumstances put it into modern high pressure systems [eg the French HDi engines] or your pump will soon be ubergerfooknackered. You do of course go into the tax implications with your eyes wide open.