Should the Reiz use 5W30 or 5W40 engine oil?
2 Answers
The oil used in the Reiz is a fully synthetic oil specifically designed by Toyota for the Reiz and Toyota's 2.5-liter engine characteristics. If the vehicle does not frequently run on highways, it is recommended to use fully synthetic 5W30 oil; if it frequently runs on highways, fully synthetic 5W40 oil is better. Below is more information about engine oil: 1. The oil number represents different categories of engine oil. Numbers such as 20, 30, 40, and 50 indicate the viscosity of the oil, with higher numbers representing thicker oil, suitable for use in high-temperature regions. Among these, 0W, 5W, 10W, 15W, 20W, and 25W, where W stands for Winter, the smaller the number before the W, the better the low-temperature viscosity. 2. The higher the engine compression ratio, the higher the required gasoline grade.
I've been driving the Toyota Mark X for eight years, consistently using 5W-30 engine oil. It runs exceptionally smooth with low fuel consumption, perfectly meeting daily commuting needs. Toyota manuals generally recommend low-viscosity oil. 5W-30 flows quickly, ensuring responsive engine performance after startup, even in winter without sluggishness. If your vehicle has exceeded 100,000 kilometers or you live in a high-temperature area with frequent summer driving, 5W-40 might offer better stability due to its thicker oil film that protects engine clearances. But don't switch arbitrarily—using high-viscosity oil in new cars can increase fuel consumption and reduce responsiveness. The key is to use fully synthetic oil with brand certification and change it regularly without delay to maximize engine longevity. Driving habits also matter: frequent high-speed driving may warrant 5W-40, while urban cruising suits 5W-30—always check the manual rather than guessing.
