The survey of 1,000 UK drivers from Mobil 1 and the Institute of Advanced Motorists (IAM) revealed that 96% say they either don’t care which oil is used in their car or simply go with what a mechanic recommends. More worrying still, even if they did care about this, 65% of respondents said they wouldn’t know which oil viscosity grade was recommended by their vehicle’s manufacturer anyway. An even larger percentage (69%) were ignorant as to which brand is recommended by their car’s maker.

Stressing the importance of choosing the right engine oil for the vehicle, Tim Shallcross, head of technical policy at the IAM, said: ‘Engine oil works in the harshest of conditions.  It must keep lubricating, cooling and cleaning your engine while being constantly hammered by huge pressures and exposed to temperatures ranging from the subzero of a midwinter cold start to the searing heat of the combustion chamber. Manufacturers know the demands placed on the oil and that is why they are so specific in the grade and quality they recommend.’ 

He added: ‘The wrong grade or specification can increase engine wear dramatically, risking expensive breakdowns as well as affecting the car’s value.’