What is the difference between 10w40 and 5w40 engine oil?
2 Answers
The difference between 10w40 and 5w40 engine oil lies in the low temperatures they can withstand: 10w40 engine oil can withstand a low temperature of minus 25 degrees Celsius, while 5w40 engine oil can withstand a low temperature of minus 30 degrees Celsius. The functions of engine oil are: 1. To alleviate friction and high temperatures; 2. To cool and lower temperatures; 3. To clean and remove impurities; 4. To absorb shocks and cushion impacts; 5. To prevent rust and corrosion. The method for changing engine oil is: 1. Lift the car, remove the protective plate, and place a container of about 10 liters under the oil drain plug; 2. Unscrew the oil drain plug, use an air gun to blow for two minutes at the oil filler port, tighten the oil drain plug after draining, and wipe it with a tissue to check for oil leaks; 3. Reinstall the protective plate, lower the car, and use a funnel to add engine oil through the filler port.
I've been driving for over a decade and tried many engine oil grades. The main difference between 5W40 and 10W40 lies in cold-start performance. Using 5W40 in winter ensures smooth engine starts with better fluidity and faster engine protection, especially in sub-zero temperatures; 10W40 works fine in summer as their high-temperature viscosity is similar with stable fuel consumption. Choose oil based on local climate – 5W40 for cold regions ensures quick starts and reduced wear, while 10W40 is cost-effective in warmer areas. I've also noticed unsuitable oil increases noise and can raise fuel consumption by up to 5%, with varying change intervals. Always consult your vehicle manual and avoid frequent brand switches that may affect performance. Simply put, lower W-number suits harsh winters, while higher numbers suffice in warmer regions.
