When I were a lad (1970's/1980's) and the only vehicles that used diesel were vans, buses and lorries diesel was CONSIDERABLY less expensive than petrol.
Clearly there must have been a change in the way Crude Oil is refined since then
Get off ya arse and go search e-bay,then come back,if you cant find it i will give you an item number,lol chemical reaction,waaaaaaaaaaaaa what a fag its only a dye,like the red is only a dye.