What Are the Effects of High-Viscosity Engine Oil on a Car?
4 Answers
The effects of high-viscosity engine oil on a car: 1. Reduces the effective power of the engine. High-viscosity oil increases the resistance to crankshaft oil stirring, leading to greater internal power loss in the engine. 2. Makes ignition difficult at low speeds. High-viscosity oil requires more torque for crankshaft rotation during cold starts, resulting in lower speeds and difficulty in ignition. 3. Poor filter cleaning performance. High-viscosity oil circulates more slowly, reducing the number of passes through the filter and failing to promptly remove wear debris from friction surfaces. 4. Inferior cooling effect. The poor fluidity and slower circulation of high-viscosity oil result in slower heat dissipation from friction surfaces, leading to poorer cooling performance and a higher risk of engine overheating. 5. Higher carbon residue. High-viscosity oil tends to have larger carbon residue particles and a higher solidification point, which can easily clog oil passages.
After years of using high-viscosity engine oil, I've often noticed that it provides excellent engine protection in hot weather, especially during highway driving where it forms a thicker oil film, reducing metal wear and keeping the car running smoothly and quietly. The downside is that in cold seasons, such as sub-zero winters, the oil flows too slowly, making the engine particularly hard to start—sometimes requiring multiple attempts to fire up, which puts a strain on the starter and battery. Fuel consumption is also an issue; I've measured the data, and on average, it consumes an extra half-liter of fuel per 100 kilometers, adding up to significant costs over time. Additionally, frequent short-distance driving makes the impact more noticeable, with a somewhat sluggish feeling during acceleration. I recommend car owners refer to their vehicle manuals to choose the right viscosity and adjust seasonally to balance protection and economy.
As an automotive enthusiast, I'm fascinated by studying the impact of engine oil on engine performance. High-viscosity oil performs exceptionally well under high-temperature and high-pressure conditions, effectively preventing engine overheating and scuffing during high-RPM situations like racing, with significantly stronger oil film strength. However, at cold starts, excessive viscosity may cause delayed lubrication, pumping difficulties, increased component load, and even premature wear. Fuel consumption is another critical factor - higher viscosity means greater engine drag resistance, slightly delayed power output, and naturally increased fuel consumption, with actual measurements showing 5%-10% higher consumption. Oil selection also depends on vehicle age and driving habits - it's more suitable for older vehicles or frequent long-distance driving, but may affect engine responsiveness and emission standards in newer cars.
I've been driving for over 30 years. The older generation of mechanics always preferred thicker engine oil, believing it offered better durability and could compensate for wear in aging engines – like filling gaps in engines with larger clearances for protection. But with modern cars being more precisely engineered, I've found this type of oil causes more problems: Cold starts become much harder, especially in northern winters when parked outside, taking several minutes to run smoothly, which isn't beginner-friendly. Fuel consumption is noticeably higher; while it's manageable on long highway drives, city traffic means refueling twice as often – those small costs add up and drain your wallet. Plus, overly thick oil tends to accumulate sludge, harming engine cleanliness over time. My advice? Don't blindly chase high viscosity; choosing the right oil based on your car's condition and environment is smarter.
