Vehicle fuel (6)
(Another definition for diesel oil that I've seen is " Type of fuel".)
(Other definitions for petrol that I've seen before include "Common car fuel" , "Fuel for road vehicles" , "Mineral oil refined as fuel" , "Liquid fuel" , "Common motor fuel" .)
(Other definitions for diesel that I've seen before include "See lid, oddly, of the fuel" , "Rudolf __ , French-born German engine inventor, d.1913" , "Common fuel for heavy vehicles" , "Vehicle fuel" , "Fuel for heavy vehicles like lorries" .)