Oil Change | Hampden, MD | AutoStream Car Care Center

A Primer for Better Understanding Oil Viscosity

Selecting the Right Oil for Your Vehicle

You know that oil is essential for your car, but do you understand viscosity? Do the many choices on store shelves overwhelm you? Worry no more. At AutoStream Car Care Center in Hampden, Maryland, we’re glad to explain oil function, viscosity, oil types (conventional, and full synthetic, synthetic blend, and high mileage) to you. Better yet, let one of our ASE certified technicians take care of oil changes and other preventive maintenance services for you. We’ve been helping our neighbors with vehicle repairs since 1999 no matter what make or model they drive. We look forward to assisting you, too!

A Review of Oil’s Functions

To understand the viscosity topic, it’s helpful to review exactly what motor oil does in your vehicle. Oil’s job is to lubricate the moving metal engine parts, reducing friction and the possibility of metal shavings sloughing off to then make contact with parts they shouldn’t. Further, it removes some of the heat generated by the internal combustion engine’s friction. This helps prevent warping since metal is malleable and can change shape if enough heat is available. Finally, it suspends debris so that dirt and particles cannot directly contact the engine components. As oil ages, it can lose some of its effectiveness. The old oil can then combine with dirt to form sludge.

What Viscosity Numbers Mean

As you can see from reviewing oil’s functions, how effective lubricant can be is impacted by its ability to coat well. This, in turn, is affected by viscosity. How motor oil behaves within an engine can change, particularly when weather (temperatures) changes. Viscosity is a descriptor of how well oil pours. Lower viscosity oil is thin and pours more easily in cold weather than does it’s counterpart, the thicker, higher viscosity lubricant. That’s relevant because lower viscosity oil is helpful for reducing friction between engine parts and getting moving quickly when you crank your car in cold temperatures, but higher viscosity oil is more effective at creating a thick protective film over those parts. Also, the thicker oil is great at sustaining oil pressure if you haul heavy loads.

When you buy oil, look at the SAE scale. The number before the “W” indicates how well the oil flows at 0 degrees Fahrenheit. That tells you the viscosity. The oil thickens less in cold weather if the number is low. The next two numbers indicate the viscosity at 100 degrees Celsius. This lets you know how well the oil can resist thinning at high temperatures. Lower numbers thin out quicker than do higher ones. For reliable oil change services that include selection of the correct viscosity for your car, schedule an appointment with AutoStream Car Care Center in Hampden.

Written by Doug Grills