Motor oil helps maintain your engine's durability, efficiency and lifespan.

But choosing the right motor oil can be a tricky task.

The wrong motor oil may accelerate engine wear or cause premature failure.

To choose the right oil for your car, consider these three factors.

One of the first things you'll need to think about is viscosity.

Viscosity is a measure of how well oil flows at different temperatures.

In most instances, there are two parts to viscosity numbers. For example, 10W-40.

The first number and letter indicate how the oil will flow in cold temperatures. The "W" stands for winter. The lower the number, the better the oil flows when it's cold outside.

The second number indicates the oil flow when the car is running. The normal operating temperature of most engines is 195 to 225 degrees Fahrenheit. The lower the number, the better it flows at these temperatures.

You can find the right viscosity for your vehicle by looking on the oil cap or in the owner's manual.

Secondly, consider if you should use non-synthetic or synthetic oil. It may simply be a matter of preference.

Non-synthetic — or conventional — oil is petroleum-based. It functions well for a majority of engines, but may need to be changed more often than synthetic options.

Synthetic oil is man made. It's designed for withstanding higher temperatures and for high-tech engines. It can be more expensive than non-synthetic oils and may not be necessary for every vehicle.

Check your owner's manual for your engine's specific needs.

Finally, if your vehicle has more than 60,000 miles on it, you may want to consider high-mileage oil. You can also choose from synthetic and conventional types.

High-mileage oil contains special additives to help keep long-running engines running their best.

Looking for more car tips? Visit allstate.com/blog.