Is 0w30 Oil Thinner Than 5w30?
3 Answers
0w30 is thinner than 5w30 oil. Both specifications have the same viscosity grade at 100°C, with the only difference being the low-temperature fluidity indicated by the number before the W. The minimum acceptable temperature for 0w30 is -35°C, while for 5w30, it is -30°C. Explanation of oil specifications: 1. Meaning of W: W (Winter) stands for winter. The number before W indicates the oil's low-temperature fluidity. A smaller number means better low-temperature fluidity. 2. Meaning of the number after W: The number after W represents the oil's viscosity grade at 100°C. A larger number indicates better engine protection under high-temperature conditions.
Indeed, 0W-30 engine oil is slightly thinner than 5W-30 at low temperatures. In the viscosity grade of engine oil, the number before the W indicates low-temperature fluidity—the smaller the number, the easier the oil flows during cold starts. For example, 0W can lubricate the engine faster in sub-zero temperatures, while 5W is slightly thicker at the same temperature, potentially making starts slower. I’ve driven in northern winters, and using 0W-30 noticeably made the car start more smoothly with less engine noise. At high temperatures, both have the same viscosity of 30, so there’s not much difference in driving performance. Choosing engine oil should consider the season and region—prioritize 0W in sub-zero areas. Don’t overlook the oil change interval during regular maintenance, especially for older cars that need more fluid oil to protect the engine, as insufficient lubrication accelerates wear. Paying attention to this small detail can really save a lot on repair costs.
Simply put, 0W-30 engine oil is slightly thinner than 5W-30 at low temperatures, offering better fluidity. The 'W' on oil bottles stands for Winter, with smaller numbers indicating easier cold-start flow. 0W remains fluid down to -40°C, while 5W only handles around -30°C. During cold starts, 0W-30 quickly coats engine components, reducing friction. At high temperatures, both have similar viscosity and perform comparably. With extensive repair experience, I've seen many owners overlook this - it's fine in summer but causes hard starts and high fuel consumption in winter. Always check your manual for oil requirements - newer cars often use lower W grades for eco-friendliness and fuel efficiency. Regular dipstick checks prevent issues; don't wait until engine noises signal oil change time.
