Oil is your engine's lifeblood: it lubricates, cools and cleans. Running low — even for a short time — can cause expensive damage, and many engines use a little oil between services as normal. Checking it takes two minutes and needs no tools. Do it every couple of weeks, and always before a long trip.
You'll need
- A clean cloth or paper towel
- The correct engine oil for your car (grade in the owner's manual, e.g. 5W-30)
- A funnel (helpful, not essential)
⚠ Safety first
- If the red oil-pressure warning light (an oil can) comes on while driving, pull over safely and switch the engine off straight away. Don't restart until you've checked the level — low oil pressure can destroy an engine in minutes.
Step by step
- 1
Park on level ground
A slope gives a false reading. Switch the engine off and put the handbrake on.
- 2
Let the oil settle
Most manufacturers recommend checking with a warm engine that's been switched off for 5–10 minutes, so the oil drains back into the sump. Checking first thing in the morning, cold, also works. Your manual says which it prefers.
- 3
Find the dipstick
Open the bonnet and look for a loop or T-shaped handle, usually yellow or orange, sticking out of the engine. Some newer cars (including many BMWs and Mercedes) have no dipstick at all — the level is shown on the dashboard or infotainment screen instead.
- 4
Pull, wipe, reinsert
Pull the dipstick all the way out and wipe it clean. Push it fully back in until it seats, wait a second, then pull it out again. This second pull is your real reading.
- 5
Read the level
The oil should sit between the MIN and MAX marks (these may be two dots, two lines, the letters L and H, or a cross-hatched area). Near MAX is ideal. At or below MIN, top up. Put the dipstick back when you're done.
- 6
Check the colour and feel
Fresh oil is amber and translucent; it darkens to brown with use, which is normal. Black, thick or gritty oil means it's overdue a change. Milky, creamy or frothy oil can mean coolant is getting into the oil (for example a failing head gasket) — don't drive the car; get it inspected.
- 7
Top up if needed
Unscrew the oil filler cap on top of the engine (marked with an oil can symbol — not the coolant or brake-fluid caps). Add oil in small amounts, about 200–300 ml at a time. The gap between MIN and MAX is roughly one litre on most cars.
- 8
Wait and recheck
Give the oil a minute or two to run down, then check the dipstick again. Repeat until the level is close to MAX, but don't go over it. Refit the filler cap firmly and wipe up any drips.
Pro tips
- Use the exact grade and specification in your manual. The wrong oil can harm modern engines, especially turbocharged and diesel engines with particulate filters.
- Overfilling is harmful too: it can make the oil froth, raise pressure and damage seals. If you've overfilled noticeably, have the excess drained.
- Motorbikes: many bikes use a sight glass instead of a dipstick, and must be held upright (not on the side stand) for an accurate reading. Your manual explains the procedure.
- Suddenly needing to top up much more often is a sign of a leak or of the engine burning oil — worth having it checked.
Stop and get a mechanic if…
- The oil is milky or frothy.
- You need to add more than about a litre between services.
- The oil-pressure light comes on even though the level is correct.
General guidance only. Your owner's manual has the final word on specs, fluids and procedures for your vehicle. Last reviewed 24 September 2026.