A survey commissioned by Mobil, purveyors of sensational engine oil, has found that 75% of British drivers don’t know how to check their car’s oil. Half of all drivers don’t even know why oil is used. Mobil sells oil, by the way.Most staggeringly, 94% of motorists surveyed by Mobil – the company that sells Mobil 1 oil – are unaware that using the correct oil can significantly prolong the life of an engine, as well as improving fuel economy. Mobil sells Mobil 1 oil.