How Much Oil Does A Car Take

Motor Maintenance Guide


Checking and topping up your car engine oil is an essential part of car maintenance. But what does oil actually do in your car, and why is it important to top it up regularly?

Oil plays an essential part in the smooth and safe running of car engines, helping to prevent friction - which can cause overheating. It does this by lubricating all of the moving parts of your engine. It also channels heat away from the combustion cycle in your engine, which is where carefully controlled explosions or combustion of the fuel-air mixture take place. Lastly, oil acts as a cleaner, picking up any dirt or dust that may have found its way into the engine.

Without engine oil and, crucially, without the right type and quality of oil, your engine won’t perform at optimum efficiency. Just as important, it may be at risk of overheating, which means that it wouldn’t be fully safe to drive. Metal parts will rub together, creating too much friction and leading to serious and irreversible damage. This means that something as simple as forgetting an oil check could turn into an expensive headache.

As a car owner, it’s your responsibility to make sure that maintenance tasks such as checking and refilling oil are carried out regularly. If you forget about it or use the wrong kind of oil, it could damage your engine and cause a breakdown.

How to check and top up your car oil

If you don’t know how to check oil levels, or when you should top up or change engine oil, you’re not alone. Around 8 in 10 drivers don’t know when to change their oil, which could be putting their car engines at risk.

Here are the essential facts you need to know:

  • Cars generally take around one litre of oil - remember that you don’t need to put this much in if you’re only topping up the oil.
  • It’s crucial to choose the right type and quality of oil for your car - the owner’s manual of your car should have all the details.
  • On average, oil should be changed every 5,000-7,500 miles if you have a modern car. If your car uses full-synthetic motor oil, you may not have to change it until you’ve travelled 15,000 miles or more. For older cars, the oil may need to be changed more regularly.
  • Your engine oil should be drained and replaced with new oil during its annual service - so depending on your average mileage, you may not need to do it yourself.
  • However, you should check your oil level every few weeks, and especially before long journeys, just in case it needs topping up. Some cars have electronic systems which inform you when oil levels are a little low, so a light will flash up on the dashboard - never ignore these important warning signs!

To top up your oil, open your bonnet and find the dipstick - making sure the car engine is off and fully cool. The dipstick is usually brightly coloured, with a round or T-shaped handle, so it should be easy to spot.

Remove the dipstick and wipe clean with a cloth, then pop it back in until you hear a click. The next step is to take the dipstick out again. You can then see how far up the oil is on the stick. You’ll see some markers showing the minimum and maximum levels, with the optimum level somewhere between these points (ideally near the top). If the oil level is below the halfway point, you should top up.

Make sure to choose the right engine oil, locate the oil filler cap (there’ll usually be an oil can symbol or the word ‘oil’ nearby) and pour the oil in. A funnel is an excellent tool here, helping you to avoid splashes. Do it slowly, adding just a little at a time to avoid overfilling.

What happens if you overfill your car with oil?

Putting too much oil in your car can cause damage to the engine. In fact, it can be just as bad as not having enough oil.

When a car is overfilled, you may notice that oil starts to leak, or you’ll see dense white smoke which indicates that excess oil is burning. Too much oil can cause pressure on the crankshaft, problems with spark plugs and poor lubrication performance. So in short, it’s not a good idea to overfill your car with engine oil.

As mentioned previously, the way to avoid this is to top up the oil very slowly, adding a little at a time. Remember that most cars take a maximum of one litre. Wait a moment or two for the oil to run down, then recheck the dipstick to see how much more you’ll need. It can take a little time, but it’s worth being cautious to avoid damaging your car.

Can you drive a car with an oil leak?

You shouldn’t drive with an oil leak if you can avoid it. It’s a fire hazard and can cause breakdowns, as well as leading to premature wear to seals and rubber hoses.

You can usually visually spot an oil leak by checking under and around your car when parked, but you can also do regular dipstick tests to see if the oil level is dropping unusually quickly. You may even see or smell smoke when you’re driving, which can be a more alarming sign of an oil leak - this happens when the oil is burning.

If oil levels are low and you suspect a leak, top up the oil to the minimum safe level and get yourself to a technician right away. Ideally, one who can carry out a home visit, but you should be able to drive a short distance to get to a garage.

Oil leaks are always best dealt with as quickly as possible. Don’t put off calling a technician, as a small leak can soon turn into a large one, and you don’t want to risk your safety and the condition of your engine or find yourself having to make a car insurance claim.