Most people don’t think much about their car motor oil, because they just take their vehicles into the auto repair shop to be serviced by a professional technician. Even if you’re not a DIY home mechanic, it helps to understand some car basics. Your motor oil, after all, is an important part of your engine, lubricating and cooling moving parts, keeping them clean and sealed from oxidation.
If you’ve ever looked for engine oil in the auto parts store, you’ll find dozens of brands, special formulations and grades. The most important piece of information to understand is the grade which tells you the range of the oil’s viscosity. Viscosity is a fluid’s resistance to flow, so oil labeled 5W30 would be less viscous than oil labeled 20W50.
The first number in the viscosity rating (in this example, 5 and 20) tells you how thin the oil is at cold temperatures, and the “W” stands for Winter. The second number (in this example, 30 and 50) indicates how resistant the oil is to thinning as the engine heats up. Ideally, you use an oil that is just thin enough when the engine is cold so you can start the engine, but it’s thick enough to continue lubricating and cooling your engine once it’s hot. If your motor oil is too thick when the engine is cold, you might not be able to start your car. However, if your motor oil is too thin when the engine is hot, it may not be able to lubricate your engine and protect it well enough from high heat.
The type of oil you need for your vehicle will depend on factors like the type of vehicle, manufacturer and driving conditions. A good place to always start is with your vehicle owner’s manual which will tell you what type of oil to use on your particular car and how often they recommend you change your oil. If you’re still unsure or no longer have a copy of your owner’s manual, your local auto repair mechanic can always help.
The Auto Stoppe is a local, family-owned and operated business serving the greater Austin area since 1980. We’re a full-service, auto repair shop providing exceptional service on both domestic and foreign vehicles.