What Kind of Motor Oil Should I Use?

Choosing the right motor oil is one of the simplest and most important ways to keep your engine running longer and more efficiently. At ABC Auto Repair in Burien, we often get asked what kind of oil is best. The answer depends on two key factors:

·      Viscosity (often referred to as "weight")

·      Synthetic vs. Conventional oil

Below, we break it down so you can make an informed decision and extend the life of your vehicle.

1. Always Follow Manufacturer Guidelines

If your car is still under factory warranty, always use the oil type and viscosity specified in your owner’s manual. Using a different type of oil can void your warranty even if the oil is technically “better.” For cars out of warranty, you still want to follow those recommendations unless there’s a compelling reason not to (which we’ll cover below).

2. Why Viscosity Matters

Viscosity refers to the thickness of a liquid. With motor oil, it’s usually listed in a format like 5W-20 or 10W-30:

·      The first number (e.g., 5W) refers to the oil’s viscosity in winter (cold temperatures).

·      The second number (e.g., 20 or 30) is the viscosity at normal engine operating temperature.

·      Lower numbers mean thinner oil. Think of 5W as being more like water, and 10W more like syrup.

If you're driving in extremely cold weather, you may benefit from a lower winter number (like 0W), as thick oil takes longer to circulate when cold. However, you should never change the second number, since your engine operates most of its life at full temperature, and that’s when protection matters most.

3. Synthetic vs. Conventional: Which Is Better?

Most modern cars can use either synthetic or conventional oil—unless your manual says otherwise. So, is synthetic worth the higher price?

Generally, yes. Here’s why:

·      Longer engine life

·      Fewer oil changes needed (if you’re outside of warranty)

·      Better performance in extreme heat and cold

·      Less sludge and build-up over time

Synthetic oil changes are a little more expensive, but they’re often a better investment in the long run. Just make sure to continue changing your oil on schedule, even with synthetic.

4. Does the Brand of Oil Matter?

All reputable motor oil brands must meet SAE (Society of Automotive Engineers) standards. Look for the “SAE certified” label on the bottle.

While some auto enthusiasts swear by certain brands, the truth is: consistency, viscosity, and timing matter more than branding.

If you’re still unsure, our Burien oil change experts can help you select the best oil for your vehicle, driving conditions, and climate.

5. Motor Oil Maintenance Tips

To maximize the life of your engine, keep these tips in mind:

·      Use the correct viscosity

·      Stick to your oil change intervals

·      Check your oil level regularly

·      Don’t let your oil get too low or too full

Need an Oil Change in Burien?

We offer quick and professional oil change services in Burien for all makes and models whether you use synthetic, semi-synthetic, or conventional oil. We’ll also inspect your fluids, check your filters, and top off anything you need.