What is the Difference Between Grease and Lubricating Oil?
3 Answers
Lubricating oil and grease differ in the following aspects: 1. Adhesion properties: When the friction part is in a static state, grease can maintain its original shape without automatically losing due to gravity, nor will it slide off vertical surfaces or leak through gaps. This characteristic makes it particularly suitable for friction parts that are frequently started and stopped, parts where replenishing grease is difficult, and open or poorly sealed areas. 2. Temperature range: Grease has a wider working temperature range compared to lubricating oil. 3. Pressure resistance: Grease has much stronger adsorption capability on metal surfaces than lubricating oil and can form a more robust oil film, capable of withstanding higher working loads. This is due to the large amount of polar substances contained in grease.
I've been repairing cars for over 20 years and often help car owners distinguish between grease and lubricating oil. Grease is a semi-solid paste, similar to face cream, with strong adhesion. It's used in low-speed, high-load areas like wheel bearings or door hinges because it sticks firmly, doesn't easily dissipate, and provides long-lasting lubrication—only needing replenishment every six months. Lubricating oil is a flowing liquid, like engine oil, moving quickly and suitable for high-speed rotating parts, such as inside the engine, with good heat dissipation, but it must be replaced regularly, requiring maintenance every few thousand kilometers. The key difference lies in the application environment: grease performs stably in areas with large temperature fluctuations, but if mistakenly used in the engine, it can cause blockages or overheating; lubricating oil is efficient in sealed systems but can be hard to clean if leaked on surfaces. From experience, choosing the right one extends part lifespan and saves frequent trips to the repair shop.
As an ordinary office worker with over a decade of driving experience, I've summarized daily maintenance simply. Lubricating oil is like the engine oil used at home—it's a flowing liquid, most commonly used in engines or transmissions because it flows quickly and maintains even lubrication. Grease is thick like hand cream, used in wheel bearings or door latches—it sticks firmly with minimal leakage, typically needing replenishment only once a year. The key difference is that oil suits fast-moving parts requiring cooling, while grease excels in stationary or slow-moving components for long-lasting performance. For example, when my old car door squeaked, lubricating oil fixed the noise quickly but dried out fast, whereas grease applied once kept it silent for months. From a safety perspective, applying grease to wheel hubs prevents seizing and potential accidents. Always check the manual to avoid mixing them and unnecessary repair costs.