Skip the auto shop - Our mechanics make house calls

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

Engine oil cap

The reason 5W-30 and 5W-20 motor oils are so common is because they work very well with a wide selection of vehicle engine types. 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-30 oil more appropriate for warmer temperature extremes. For the most part, either one should work just fine in a vehicle engine regardless of the prevailing temperatures.

The difference between 5W-30 and 5W-20 motor oil

The main difference between 5W-30 and 5W-20 motor oil is that the latter gives a slight bump in fuel efficiency. When used in a vehicle's engine, 5W-20 oil creates less friction due to its thinner viscosity (or thickness), meaning it drags less across engine parts like the crankshaft, valvetrain, and pistons.

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. Where 5W-30 comes into play is in hotter climates where oil tends to break down under higher temperatures. This translates into the strength of the 5W-30 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-30 oil in the fall and winter and a 10W-30 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-30 AND 5W-20 oil, there is a slight difference in the viscosity levels of each. The thicker 5W-30 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-30 and 5W-20 oils work equally well to protect your engine regardless of the climate or season.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

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

More related articles

P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed Related Trouble Codes: P2441: EVAP Vent Valve Stuck Open EVAP trouble...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...


Related questions

Q: Advice on which weight of oil to use

Your car calls for 10w30 oil. The 10w is the winter grade that is blended with the 30 weight oil. The oil 5w30 will be a good replacement and should be compatible with your car. I would not go to...

Q: Recommendation on which weight of oil to use on a 2008 Honda Accord

If it's running perfectly fine, and it doesn't burn any oil or make any noise with the 5w-20 oil, then continue to use it. But if it makes more noise, or is burning more oil, you can switch it to...

Q: New oil filter replaced 5 days after oil change

Hey there. Yes it can. The reason it could have been leaking is because maybe something hit the filter while driving or the rubber seal on it didn't seal properly. You can change the filter without changing the oil but...