What is the difference between 5W-30 and 10W-30

Oil is the lifeblood of every motor. Without it, your ride is nothing more than a paperweight on wheels. With respect to preventative maintenance, changing the oil on a regular basis is crucial. It can easily mean the difference between your engine going 100,000 or 200,000 miles, not to mention the high cost of repairs that come with increased wear and tear! A job that can take any semi-experienced car owner about 20 minutes to complete, an oil drain and refill is not something to take lightly.

Oil thickness: why it is important
Now that we have established the importance of this fluid, you may be wondering what type to use in your motor. The viscosity or thickness of particular oil determines what engine temperature it will flow better. The higher the initial number, the thicker the oil is. Therefore, drivers who live in colder climates or those prone to near or below freezing temperatures during the winter months, are advised to use a thin grade oil (e.g. 5W-30) at the appropriate time of year.

All vehicles are designed to handle specific oil weight/viscosities, and this information is usually labeled on the top of the crankcase, typically on the oil cap for convenience. In order to keep your motor protected and running optimally at all times, never use an oil that is outside of the manufacturer’s stated recommendations.
Thinner oil is needed to flow quicker in a cold motor, which is why there is no need to insert anything less than 10W-30 in a car in summertime. Of course, certain high-performance oil types are made to withstand extreme conditions, including temperature, aggressive driving, dusty/dirty climates, etc. The better quality the oil (i.e. fully synthetic vs. conventional), the longer you can go without changing it. Ken Scales Auto advises Oregon residents to change install 5W motor oil before the first freeze, especially for folks who live in the eastern part of the state.