A few years ago I bought a new car, and was proudly showing it off to some colleagues when one of them sniffed and said: “I had one of those once. It blew up.”

I felt rather deflated until he added, almost as an afterthought, “Of course, I never put any oil in it.”

He found out the hard way that, even if you get your car serviced regularly by a garage, it's still a good idea to keep an eye on the levels of essential fluids.

Most drivers know the basic drill for checking the oil level: make sure the car is parked on level ground, let the engine cool, open the bonnet and find the dipstick – often the top of it is a small ring coloured yellow. Pull out the dipstick, wipe the bottom end of it clean with a rag or a paper towel, then push it back into its hole and pull it back out again.

There will be two marks on the dipstick – the upper one is the maximum oil level, the lower one is the minimum. If the level of oil is below the minimum, add oil through the filler on top of the engine. The car's handbook will say what type of oil you need, and should also tell you how much you would need to add to top-up from 'min' to 'max'. If you can't find a figure, estimate a coffee-mug's-worth, wait a minute or two for the fresh oil to work its way through the engine, then recheck on the dipstick.

Overfilling wastes oil and in extreme cases can cause engine damage – so it's worth taking a few minutes to get it right.

But if you do find your engine needs topping up regularly, ask yourself where the oil has gone – and why. There are only two causes of oil loss – leaks (look for stains on the drive) and engine wear (look for blue smoke from the exhaust). Most modern cars will use very little oil between services, so if you have to keep topping up that’s an indication there’s something amiss.

Oil Tips

  • Don’t wait for the oil light to come on before you top up the engine – the oil light indicates low oil pressure, not low oil level. If it comes on while the engine is running, there’s already a chance damage is being done.
  • Some modern engines no longer have dipsticks – instead they automatically check the engine oil on start up and display a warning in the instrument panel if the level is low. If you can’t find a dipstick, consult your car’s handbook.
  • Look out for ‘summer check’ offers at car dealers – these check oil and other essentials, either for free or for a small fee. The process only takes a few minutes.