Is 10W40 Motor Oil Thicker Than 5W30? Understanding Viscosity Ratings
Discover why 10W40 oil is thicker than 5W30 at operating temperature and what those viscosity numbers mean for your engine.
0 views
10W40 is thicker than 5W30 at the engine's operating temperature. The first number (5 or 10) refers to the oil's viscosity at cold temperatures (the lower the number, the thinner the oil), and the second number (30 or 40) indicates the viscosity at the engine's operating temperature (the higher the number, the thicker the oil). Therefore, when warmed up, 10W40 oil maintains a higher viscosity, offering a thicker protective layer compared to 5W30.
FAQs & Answers
- What do the numbers in motor oil ratings like 5W30 and 10W40 mean? The first number indicates the oil's viscosity at cold temperatures, where a lower number means thinner oil. The second number represents the viscosity at engine operating temperature, with a higher number indicating thicker oil.
- Is 10W40 better than 5W30 for all types of engines? Not necessarily; 10W40 is thicker at operating temperature, which might benefit older or high-mileage engines, while 5W30 is thinner and often recommended for newer engines to improve fuel efficiency.
- Can I switch between 5W30 and 10W40 motor oil? Switching is possible but depends on your vehicle's manufacturer recommendations and operating conditions; using the correct viscosity ensures optimal engine protection.