How Does Oil Viscosity Affect the Engine?

☝️ First, it's essential to understand the role of oil (engine oil) in the engine to grasp what viscosity is.

🛢️ The primary purpose of oil in the engine is to lubricate metal components, reducing friction. Excessive friction can lead to wear and tear on parts, and the lubrication process also helps cool the engine 🆒. Additionally, oil can seal the gaps between the pistons and cylinders, providing a protective layer that guards engine components 🚫 against sludge, acid, water, and other substances that can cause rust and corrosion. Finally, oil helps remove acids and silica oxidation from engine parts, and the 🌟 crucial element in all these functions is "oil viscosity."

Common viscosity options include: 0W-20, 0W-30, 0W-40, 5W-30, 5W-40, 5W-50, 10W-60...

How Does Oil Viscosity Affect New and Old Engines? ⚙️

The term "viscosity" refers to the thickness of the oil and its resistance to flow. A higher viscosity value ⬆️ indicates thicker oil, which is particularly important for the bearing clearances in the engine. Older engines were manufactured with much looser tolerances, so thicker oils like 10W-30 were the most recommended viscosity for OE in the 1990s and earlier.

However, modern engines utilize better technology and stricter tolerances during manufacturing 🔨, meaning that thinner oils must be used to ensure ✅ proper lubrication of engine bearings. Thinner oils can circulate more quickly and freely throughout the engine 🔄, and in most cases, the entire system will use less oil than before. In recent years, new engines from the VW Group even use 0W-20 viscosity oil, certified as VW 508 00 / 509 00. The primary reason for this is that 0W-20 operates with lower resistance ⏩ in the engine, allowing for fuel savings ⛽ without harming the engine.

Why Do Race Cars Use Thicker Oil? 🏎️

Thicker oil has a unique characteristic: it tends to adhere more easily to engine components. When engine tolerances deteriorate or when used in high-rev situations, such as in racing or off-road events, the adhesive properties of thicker oil come into play, providing better engine lubrication. Therefore, for more aggressive drivers who occasionally 🏔️ drive uphill, it's important to pay extra attention to this.

Ultimately, viscosity determines how engine oil responds to changes in 🌡️ temperature, pressure, and speed. However, it's crucial to avoid randomly using oils of different viscosities; you should always follow the 🏭 manufacturer's recommendations regarding oil viscosity.