It’s a familiar scenario. You drive onto a petrol station forecourt and pull up alongside the pumps. Staring back at you is a range of multi-coloured nozzles labelled with an equally confusing array of names: Fuel Save, V-Power Nitro+, Synergy, Synergy Supreme+, Regular Fuels, Ultimate, Momentum. The list goes on, with all retailers offering standard and premium fuels. The question is: should drivers fill their car with premium fuel?