Is Higher or Lower Engine Oil Viscosity Better?
2 Answers
Engine oil viscosity should primarily be chosen based on what suits the vehicle. The best viscosity is the one that fits the vehicle's requirements. Below is information about engine oil: 1. When selecting engine oil, vehicle owners must understand the temperature environment in which the vehicle operates. They should then purchase oil according to the grade and viscosity requirements specified in the vehicle's manual. Carefully check the grade and viscosity markings on the oil's packaging, ensuring the oil meets the minimum grade and above. For example, in Sichuan, where temperatures vary throughout the year, multi-grade viscosity oil like SAE 15W-40 is typically suitable. In Chongqing, where summers are hotter, it's better to choose oil with a viscosity of 50. 2. The first few thousand kilometers of a new car are called the break-in period. During this time, minor protrusions on parts are worn down, allowing moving parts to fit together more tightly and operate more smoothly. Choosing the right oil during this period is crucial. Generally, oils with viscosity grades of 15W/40 or 40 are recommended for break-in. New cars or engines after major repairs have uneven or overly tight clearances between parts, which need adjustment during the break-in period. Using oil with higher viscosity can make it difficult to form a lubricating film on poorly fitted friction surfaces, leading to dry friction, excessive wear, and even mechanical failures like bearing seizure or crankshaft damage. Lower viscosity oils, due to better fluidity, provide superior cleaning and cooling effects. 3. If the vehicle is primarily used in the city where frequent traffic jams lead to stop-and-go driving, it's considered severe driving conditions, and it's advisable to shorten the oil change interval.
Having driven for nearly two decades, I can confidently share my thoughts on engine oil viscosity—a common concern. Higher viscosity means thicker oil, which offers better engine protection during summer heat or long-distance driving, reducing component wear, though it may slightly increase fuel consumption. Lower viscosity means thinner oil, ensuring smoother cold starts in winter, quicker ignition, and better fuel efficiency, but it might lack sufficient protection under high temperatures, potentially leading to engine overheating or wear. The choice between higher or lower viscosity truly depends on your car’s manual recommendations, as requirements vary by manufacturer. For instance, Japanese cars often recommend lower viscosities like 5W-30 or 0W-20, while older American models may suit higher viscosities like 10W-40. Seasonal factors also matter—I live in the north, so I switch to lower viscosity in winter and slightly higher in summer. Avoid arbitrary changes; mismatched viscosity can cause cylinder scoring or oil burning, damaging the engine long-term. When getting an oil change at a reputable shop, let them help select the right match for peace of mind and safety. Remember, balancing protection and efficiency is key—don’t compromise engine health for minor savings on fuel or costs.
