What is the difference between 5w40 and 0w40 engine oil?
2 Answers
The main difference lies in their resistance to external low temperatures. 0w40 has better low-temperature fluidity compared to 5w40. Different definitions: 0w40 is a synthetic oil, which is artificially manufactured. During production, various natural substances are chemically decomposed and then synthesized with other materials to ultimately produce synthetic oil. 5w40 is a semi-synthetic oil, one type of automotive engine oil, which uses semi-synthetic base oil. Different focus areas: 0w40 fully synthetic oil contains 100% non-conventional, high-performance fluids; 5w40 semi-synthetic oil (also known as blended oil) contains a smaller percentage of these high-performance fluids and includes conventional mineral oil.
From a professional perspective, the core difference between these two engine oils, 5w40 and 0w40, lies in the number before the W, which represents low-temperature fluidity. The 0w40 performs better in tests at -35 degrees Celsius, making the engine easier to rotate during cold starts in extremely cold weather, thereby protecting critical components. On the other hand, 5w40 is more suitable for relatively warmer environments around -30 degrees Celsius. Both share the same high-temperature viscosity of 40, providing similar high-temperature protection. When choosing, consider the climate—0w40 is superior for those living in cold northern regions or areas with extreme winter cold, while 5w40 is sufficient for milder southern regions. It also affects fuel efficiency: oils with better low-temperature fluidity reduce starting torque, potentially saving 1-2% in fuel consumption. In summary, selecting the right type based on your driving region can extend engine life and provide peace of mind. I base my conclusions on data, which is determined by international viscosity standard tests.
