Apart from the fact that it is gold coloured and helps the engine go, most people tend to gloss over its role in modern cars.
But a driver’s or fleet manager’s lack of interest could cost a company thousands of pounds through basic errors that a couple of well-chosen words and a slip of paper might put right.
Put simply, oil is the lifeblood of any engine and putting a bit of effort into choosing the right stuff will keep your budget in the black in the long-run.
For inspiration it is worth turning to Jonathan Garton, general manager of Total Lubricants, who achieves the impossible – he makes oil sound interesting.
He points out that oil is one of the most hi-tech parts of a car and all that stands between the engine running smoothly and the pistons self-destructing in a shower of metal shavings.
An infinitely thin layer of oil keeps all the moving parts of the engine from scraping against each other, which keeps the engine from wearing and allows it to last longer, remain efficient and stay reliable.
About 80% of modern oils are synthetic or semi-synthetic, which allows manufacturers to stretch service intervals to more than 20,000 miles for some models.
But, Garton points out, there is a price to convenience. He said: ‘Drain intervals for some manufacturers vary depending on the engine oil you use.
‘So if you have the highest quality oil, then the drain interval might be 20,000 miles, while a low grade oil brings the oil change interval down to 10,000 miles.
‘It is beholden on fleets, leasing companies and garages to put the right oil in. They need to remember that although synthetic oil is more expensive, it pays for itself in increased service intervals.’
Although it is difficult to imagine hassled company car drivers eagerly scanning the back of packs of oil to make sure they choose the right one if they need to top up, it is a valuable lesson to learn, according to Garton.
Details of the right engine oil lie deep within the untouched driver’s handbook or vehicle operating manual and are normally easy to find. The vast choice of engine specific oils available means taking time does pay off, especially with the latest engines.
He warned: ‘When an engine is fitted with a particulate filter, the filters can’t cope with things like phosphorous, sulphated ash and so on, which poison the catalyst.
‘You must use specialist oils or it is guaranteed it will damage the filter. It might just get the car through the first three years, but eventually the filter will fail and cost £1,000 to replace, all for a few pounds on oil.
‘All you need to do is use the right top-up oil and service oil.’
To help, the firm has created oil top-up packs that can be velcroed into the boots of cars, but the main challenge is education.
He said: ‘Technology is moving all the time, but drivers just need to look in the handbook. However, fleet managers need to be sure that garages are using the right service oil as well.’
Drivers also need to understand that modern engines still need to be treated with care, including regular oil checks.
Garton, who has been with Total 14 years, including spells in Turkey and Paris, as well as working in the offshore oil industry before joining the firm, said: ‘You should check your oil a minimum of once a month.
‘Many new cars have an oil level warning system too. All engines use some oil, but it is just knowing the right type to use if you need to top up. Most of the time, wrong means cheap.
‘Extended drain intervals have come back to bite people. When it was every 6,000 miles drivers did not need to check their oil between services, but at 20,000 miles it will not go that far without checks.
‘Drivers have got used to not needing to check and now they will have to learn that they must.’
Total’s oil range, which includes the Elf brand, is used in about one million cars and the firm sells some 30,000 tonnes of lubricants a year, worth £28.5 million.
Garton added: ‘Oil affects everything, such as reliability, cold starting performance, engine longevity, fuel economy and so on.
‘It can’t be a case of drivers just picking up a litre of oil they use in the lawnmower and just chucking that in.
‘If spending an extra few pounds of the right high-grade oil that will keep the engine going for longer, then it really is a no-brainer.
‘There is a lot of money to be saved, but companies need to educate their drivers and make sure their garages understand too.’