Why Are 5W-30 and 5W-20 Oils So Common?

Schedule Oil Change
Service Area

$92.73 - $160.32

Price range for all vehicles
Average rating from 17,791 customers who received a Change Oil and Filter.

In terms of taking care of your car, there's not much more important than changing oil. The reason 5W-20 and 5W-20 motor oils are so common is because they work very well with a wide range of engines. Most often, these types of oils best cover the range of possible temperatures, with a 5W-20 oil more geared toward colder climates and a 5W-20 oil more appropriate for warmer temperature extremes. For the most part, either one should work just fine in an engine regardless of the prevailing temperatures.

The difference between 5W-20 and 5W-20 motor oil

The main difference between 5W-20 and 5W-20 motor oil is that the latter is less viscous (or thick). When used in a vehicle's engine, 5W-20 oil creates less friction due to its thinner viscosity, meaning it causes less drag across engine parts like the crankshaft, valvetrain, and pistons. This can provide a slight bump in fuel efficiency.

The thinner nature of 5W-20 oil also allows the oil pump to move it from the oil pan to the rest of the engine more easily. This makes 5W-20 preferable for very cold climates, when having thinner oil that can flow easily on start-up is important. Where 5W-20 comes into play is in hotter climates where thin oil tends to break down under higher temperatures. This translates into the strength of the 5W-20 oil keeping it from breaking down as quickly as the 5W-20 oil, providing better overall engine part protection.

Single viscosity vs. multiviscosity oil

Designed to operate in a multitude of temperature ranges, a multiviscosity oil represents one of the best motor oils for cars. The single viscosity oils of the past provided protection during either hot or cold weather, depending in large part on the weight, or lower temperature extreme at which they operated. This usually meant using a 5W-20 oil in the fall and winter and a 10W-20 in the spring and summer.

A multiviscosity oil, on the other hand, uses special additives to improve the viscosity of the oil. Called, ironically, viscosity improvers, these additives expand as the oil heats up, providing a higher viscosity at warmer temperatures. After the oil cools, these improvers shrink, making the oil thinner, best for use during cooler engine operation.

How oil additives help clean and protect an engine

Oil manufacturers use additives in oil for cars to improve the performance of the oil when it comes to lubrication. In addition, some other affects of additives in oils include cleaning engine deposits from engine parts, inhibiting corrosion or rust inside the engine, and keep the oil from breaking down as bad either due to oxidation or extreme temperatures.

Which oil should vehicle owners use?

When looking for a motor oil that works best in your vehicle, keep certain factors in mind. While not a lot of difference exists between the protection provided by a 5W-20 AND 5W-20 oil, there is a slight difference in the viscosity levels of each. The thicker 5W-20 should see a slight advantage when operating at higher temperatures, while the thinner 5W-20 oil should provide better engine protection at lower temperature levels and has the added benefit of slightly improving fuel efficiency.

The flexibility of today's synthetic motor oil means that both 5W-20 and 5W-20 oils work equally well to protect your engine regardless of the climate or season. Castrol provides a wide range of multiviscosity oils to suit your engine. YourMechanic brings top-quality Castrol synthetic or conventional oil to every mobile oil change.


Next Step

Schedule Oil Change

The most popular service booked by readers of this article is Oil Change. Yourmechanic’s technicians bring the dealership to you by performing this job at your home or office 7 days a week between 7AM-9PM. We currently cover over 10k cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Oil Change reviews

Excellent Rating


YourMechanic Oil Change Service

Average Rating

4.9/5

Number of Reviews

17,791

Rating Summary
16,631
769
155
72
164
16,631
769
155
72
164

Joseph

31 years of experience
540 reviews
Joseph
31 years of experience
Toyota 4Runner - Oil Change - Dallas, Texas
Very professional job. Showed up on time and completed the work as requested in a timely manner. Very happy with the job done by Joseph.
Cadillac CTS - Oil Change - Dallas, Texas
Joseph was very professional. He made sure to communicate with me about everything. He worked quickly and answered all my questions. Will use him again!

Ryan

6 years of experience
8 reviews
Ryan
6 years of experience
Audi S4 - Oil Change - Lansdowne, Pennsylvania
Showed up on time and completed the oil change in a timely manner without any problems, went very smooth, would recommend.
Volvo V90 Cross Country - Oil Change - Philadelphia, Pennsylvania
I did an oil change with him. Ryan showed up even little earlier and was very thorough and detail-oriented. He did every step very carefully and even wiped off the area. I appreciate his professionalism.

Jerimiah

17 years of experience
324 reviews
Jerimiah
17 years of experience
Toyota Corolla - Oil Change - Las Vegas, Nevada
Jerimiah is always friendly and professional. He is quick, efficient and always goes above and beyond!
BMW 328is - Oil Change - Las Vegas, Nevada
Jerimiah, as in the past I felt confident that you would give me your professional advise should you find it necessary to point out a potential need for other services. As I pointed out to you I feel that with the competence of a mechanic there should also be a trust to make the owner save for her/him and others while driving...Thank you

Peter

23 years of experience
227 reviews
Peter
23 years of experience
Porsche Cayenne - Oil Change - Tarzana, California
Peter was great. Performed oil change fairly quickly, very professional and provided a few good tips about my vehicles.

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE