Should Malibu use 5w40 or 5w30?
3 Answers
The oil cap on the Malibu indicates 5w30, so it is recommended to use 5w30. Difference in high-temperature viscosity: 5w30 has lower high-temperature viscosity, offering better fluidity and faster engine cooling; 5w40 has higher high-temperature viscosity, with poorer fluidity but less fluctuation and greater stability. Different applications: 5w30 can effectively reduce fuel consumption and has lower noise, making it suitable for new cars or naturally aspirated engines; 5w40 has higher viscosity and is more suitable for older cars. The number after the 'W' in the oil grade indicates the kinematic viscosity of the engine oil at 100 degrees Celsius. A higher number means greater viscosity, ensuring better and more stable protection at high temperatures, meaning it is less likely to thin out under high temperatures.
For cars like the Malibu, the official manual mostly recommends using 5W-30 oil, especially if your car is a 2013 or later model. I’ve driven an older Malibu and always used 5W-30—it starts quickly, has low fuel consumption, and runs smoothly for daily commutes without any issues. Choosing oil depends on viscosity: lower numbers like 5W-30 make cold starts easier, while W-40 offers better protection at high temperatures. However, the Malibu’s engine is designed for thinner oil, and using the wrong type may increase fuel consumption or accelerate wear. I suggest checking your owner’s manual or the maintenance alerts in your car’s app first. If you don’t have the manual, search online for your model year. If you live in an extremely hot area, using W-40 temporarily is fine, but avoid long-term use to prevent engine lifespan issues. Don’t delay oil changes—I do mine every 6,000 km to keep the car in good health.
I think 5W-30 is sufficient for the Malibu, especially if you drive gently. I don't drive long distances often, mostly city driving, and 5W-30 keeps the engine running smoothly with good fuel consumption control. On the other hand, W-40 has higher viscosity, which provides better protection against high-temperature damage if you enjoy speeding or frequently drive on highways. But I suggest not rushing to switch—first, check your car's model year; newer cars are better off with W-30 for peace of mind. Choosing the right oil isn't trivial—it affects power response and wear rate. During hot summer months, check the oil level more often to prevent leaks. I usually ask the mechanics at the repair shop to test the engine condition with a diagnostic tool—it's much better than guessing blindly, saving money and ensuring safety.
