Oil Changes and Fuel Economy

When talk turns to fuel economy, oil changes aren’t typically the first thing mentioned. But that is starting to change.

Manufacturers now require increasingly lighter weight engine oil in vehicles. For example, they are replacing 5w30 and 5w20 with 0w16—an oil so thin and lightweight that it feels like you are pouring water into the engine!

This is just one of the changes driven by the corporate average fuel economy (CAFE) standards, which are set by the state and require all carmakers to average 54.5 MPG by 2025.

Oil Changes And Fuel Economy

For years, old school mechanics used 20w50 oil for their cars. It is high-viscosity, providing an ample cushion against metal-to-metal contact. It also acts as a more effective sealant than thinner oils. Today, though, two of the most popular oils are 5w20 and 0w30. The difference between them is apparent—the lighter weight engine oils look and feel like you are giving your engine a long, tall drink of water, while the heavier weight oils have the same consistency as the syrup you pour on your pancakes.

The reason this affects gas mileage is pretty simple. Though thicker oil protects, it also creates resistance inside the engine, slowing down moving parts and lowering your miles per gallon.

Switching to Thicker Oil

Customers sometimes ask if they can install 5w30 oil in a car requiring 5w20 to increase protection. Using a slightly thicker oil will not hurt internal engine components, but it might lower fuel mileage. Be very careful, though! Thicker is not always better, especially when it comes to engine oil. Using heavy oil, such as 20w50, in a modern vehicle will cause issues. We strongly recommend giving us a call before switching motor oils!

What are some other solutions manufacturers are coming up with to meet CAFE standards?

  • Lighter materials throughout the vehicle
  • Turbochargers
  • Gasoline direct-injection
  • Hybrid systems
  • Smaller engine sizes
  • 10-speed transmissions
  • Synthetic oils in transmissions

With all of these changes increasing the complexity of your vehicle, preventive maintenance from highly-trained professionals is more critical than ever. For hometown service you can count on, call the friendly, helpful experts at Certified Auto Specialists at 626-541-2149 or contact us online today!