10W—30

10W tells how viscous the oil is at -18°C. The higher the number, the thicker the oil. If you live in a cold place, you should use 5W oil in winter, the engine will then get better lubrication when starting from cold.

30 tells how viscous the oil is at 100°C. If the engine uses oil when you have 30 oil, you can try changing to 40 oil, which is thicker. It may also help to change to thicker oil if you get blue smoke from the exhaust when you start the engine.

You do of course use an engine heater in the winter?

Lurium

• Should you have additives in the oil?
— Maybe, maybe not. It can work against its purpose if the additive and the oil are not compatible.

Pro-Long and QMI may be worth considering.

Control

Don't rely too much on the meter inside the car (if it works at all).

The car must be parked on a level surface, and the engine must be cold. Pull up the dipstick and wipe it with a paper. Put it back in and wait a bit. Pull it up again and read the oil level. It must be between the two measuring lines. If it is too little, you fill in a little, if it is too much, you drain a little.
NB! It is very important that the level is not above the top line.

— How often?

Minimum every weekend.
Incidentally, you can never check the level too often.

Oil change

Oil filter for CX diesel.

• The bottom plug is easiest to loosen with a large pair of wisegrip pliers.

1. The engine must be warm or lukewarm.
2. Raise the car to the highest position and place solid jack stands under the front jack mounts (and preferably also under the rear ones if it has a tendency to sink back down quickly).
3. Pull the dipstick up a little and loosen the oil filler cap.
4. Drain the oil (be careful not to burn yourself; e.g. use winter-lined work gloves).
5. Remove the old oil filter (you may need to use oil filter pliers).
6. Fill the new oil filter with new oil.
7. Wait an hour so that the engine can drain well.
8. Put on a new gasket (copper disc) and screw in the bottom plug.
9. Drain the oil out of the new filter (if it is to be mounted upside down), apply oil to the gasket, and screw it on until the gasket barely touches. Then tighten ¾ turn.
10. Fill in new oil.
11. Wait 5 minutes and check the level.
12. Start the engine and check that you have no leaks (the sump plug, the sump, the oil filter).
13. Remove the jacks and put the car in its normal position.
14. Write down the mileage and oil type, and that the oil filter has been replaced.

— How often?

Oil at least twice a year: Late autumn and early spring, regardless of mileage. If you do a lot of short driving distances in the winter, and you don't use an engine heater, you should also change it once in the middle of winter.
Oil filters should be replaced once a year on petrol engines, and twice a year on diesel engines.