
Car engine oil normal values vary depending on the engine type: 1. For gasoline engines, the normal range is between 190 to 490 kpa; 2. For diesel engines, the normal range is between 290 to 590 kpa. The functions of car engine oil include: 1. Lubrication: Reducing friction and wear between moving parts; 2. Cooling: Absorbing heat generated in the combustion chamber and piston top to cool the engine; 3. Sealing: Filling the gaps between piston rings and cylinder liners to prevent combustion pressure leakage; 4. Cleaning: Preventing contaminants and oxide impurities from adhering to internal engine components, maintaining cleanliness; 5. Rust prevention: Neutralizing acidic substances produced by combustion gases to prevent engine rust and corrosion.

I've been driving for over a decade and make it a habit to check the dipstick weekly. That little metal strip has two marked points - the oil level should ideally sit between them. The most accurate reading is taken when the engine is cold, like first thing in the morning before starting - pull it out, wipe it clean, then reinsert it. If it's below the lower mark, top up with the same grade oil immediately, otherwise insufficient lubrication could cause cylinder scoring; if overfilled beyond the upper limit, the crankshaft churning the oil will produce white smoke and fuel consumption will spike. Remember when changing oil - don't pour in the whole container at once, add three-quarters first, wait ten minutes, then check the dipstick before topping up. Older vehicles need more frequent checks as they naturally consume some oil - about half a liter every 5,000 kilometers.

Last time during maintenance, the technician taught me that more engine oil isn't necessarily better. The normal range is between the L and H marks on the dipstick. After turning off a warm engine, wait five minutes before measuring, otherwise the oil clinging to the walls will give a falsely high reading. My Honda usually takes about 3.7 liters to reach the midpoint, while my friend's Volkswagen requires over 4 liters. The dashboard will show a red warning light when oil is insufficient, but don't wait for the alarm to take action. When adding oil, it's better to pour less and top up twice rather than overfill at once - excess oil can only be removed by extraction. Also, in northern winters, using thinner oil with the same dipstick level helps with cold starts.

Novice drivers often overlook checking the oil level, but it's actually very simple. Half an hour after turning off the engine, pull out the dipstick and observe the oil mark position on the metal rod - ensure it's between the minimum and maximum indicator lines. From my experience, the ideal position is one-quarter above the midline. If it's low, try adding half a liter; if overfilled, you must drain some as excess oil can damage the catalytic converter. After maintenance, recheck at 2,000 km, especially for turbocharged vehicles which consume oil faster. Always keep a bottle of the same specification oil in your trunk, and checking before long trips gives peace of mind.


