New research has revealed that as many as 21.8 million motorists in the UK do not know that their engine oil expires. 

A new study by Kwik Fit has found that a whopping two thirds 65 per cent of drivers do not know that oil deteriorates over time – particularly concerning as drivers of vehicles with old or dirty oil may not experience any noticeable effects until it is too late.

The research shows that many motorists are failing to regularly check or change their engine oil, which could potentially cause irreparable damage to their vehicles. 

Car manufacturers recommend that oil within the engine is changed every 12 months. Motoring experts say it is ‘extremely concerning’ that 3.7 million motorists in the UK believe they can safely wait over three years before their engine oil loses effectiveness. The research showed that one million drivers say they never have the engine oil in their car changed.

It seems that motorists really do get wiser with age when it comes to changing and replacing their oil. The figures reveal that those over 65 are most vigilant, with 68 per cent ensuring their oil is changed at least every 12 months, compared with less than half of those aged between 18 and 24. 

There is also a stark difference between the sexes when it comes to oil knowledge.  The Kwik Fit study found that female drivers are nearly three times more likely to be unaware of how frequently their car’s oil is changed than male motorists (24 per cent in comparison to nine per cent respectively).

Roger Griggs, director of communications at Kwik Fit, said: “These results are alarming, with many motorists admitting they pay very little attention to what is happening under their car’s bonnet. There seems to be a serious lack of knowledge when it comes to oil and this appears to be more common among younger motorists. These findings only confirm that more needs to be done to ensure people are aware of the problems and expense that neglecting regular oil changes can lead to.

“In addition, drivers need to make sure that they are using the oil that fits the manufacturer’s specification. Using cheaper oil can be a false economy if it does not meet the specific lubricant requirements of their engine. The most common failures we see due to incorrect or deteriorated oil is the blockage of the exhaust gas recirculation valve and the diesel particulate filter. Incorrect oil has even been known to cause significant internal engine damage and the effects are incredibly tricky (or complex) and expensive to reverse.” 

Engine oil will degrade over time due to dirt ingress and additive depletion – this is the natural result of the oil doing its job of keeping moving parts lubricated and clean. Motorists should always follow the manufacturer’s recommendations on how often oil should be changed and ensure that oil levels and subsequent top ups are given when required to maintain standards between oil changes.

Mr Griggs added: “It is important drivers check their own engine oil levels on a weekly basis using the dipstick and we recommend that the car is regularly serviced to ensure that the oil is changed every six months or so. Many engines that are using old or insufficient oil may experience knocking noises and in this instance, the car should be taken to a garage as soon as possible to avoid irreparable damage to the engine.”