What are the effects of thin engine oil on the engine?

[LaJonathan]

Thinning engine oil can lead to excessively low oil pressure and cause semi-dry or dry friction between various mating components. Below is relevant information about engines: 1. Introduction: An engine is a machine capable of converting non-mechanical energy into mechanical energy. 2. Classification: Includes internal combustion engines (reciprocating piston engines), external combustion engines (Stirling engines, steam engines, etc.), jet engines, electric motors, etc. 3. External combustion engines: These refer to engines where fuel is burned outside the engine. 4. Internal combustion engines: Internal combustion engines, or reciprocating piston engines, differ most from external combustion engines in that fuel is burned inside them. There are many types of internal combustion engines, with common gasoline and diesel engines being typical examples.

[DeAnderson]

Speaking from over 20 years of driving experience, using thin engine oil is no trivial matter. It may work fine during cold starts—flowing quickly to warm up the engine faster and making startups smoother. But the real trouble comes during high-temperature, high-speed driving: the oil film becomes too thin to properly cushion metal components, leading to friction and scratches. After I once switched to thinner oil, my engine started making a loud humming noise during uphill climbs, with the oil pressure gauge constantly warning me. A later inspection revealed worn piston rings. Long-term use of thin oil increases component wear and can lead to oil burning issues, with shockingly expensive overhaul costs. My advice? Don’t risk saving a few bucks on oil—always stick to the viscosity recommended in your vehicle’s manual (e.g., 5W-30 for most modern cars). Check oil levels regularly during maintenance, and if issues arise, switch back to standard oil promptly.

[IrisFitz]

As someone with some automotive knowledge, I believe low oil viscosity has its pros and cons. It reduces internal friction, improves engine efficiency, and saves some fuel, especially enabling smoother cold starts. However, it becomes risky under high temperatures and heavy loads—oil that's too thin turns watery, with poor lubricity and fragile oil films. I once tried thin oil on the highway, and the engine noise was deafening, with unstable oil pressure triggering warning lights. The mechanic said it accelerated component wear. This not only causes short-term discomfort but also shortens engine life and increases maintenance costs. Thin oil may work for short city trips, but avoid overly low viscosity grades for frequent long-distance driving or hot climates. Stick to the manufacturer-recommended oil type to balance protection and economy, avoiding more losses than gains.

[ArthurLee]

Daily short-distance driving revealed significant impact from thinning engine oil. After switching to lower viscosity oil, the engine noise increased, making driving less enjoyable. Cold starts were easier, but during summer highway driving, oil pressure dropped with increased noise. When using the wrong oil, the engine light came on, and inspection showed accelerated wear. Now using the recommended 5W-30 results in quieter operation and smoother performance. It's advised not to switch to thinner oil just for fuel economy—risks are high. Regularly check oil levels during maintenance to prevent issues, ensuring lower upkeep costs and greater peace of mind.