Can a simple oil change give you a significant increase in fuel economy? Can the cost of changing your oil provide savings for your wallet? These are questions that oil geeks talk about all the time on various forums. With the impressive power gains, we had gotten with Idemitsu Zepro Eco Medalist synthetic oil in our last dyno test, we knew that the oil was getting the power via a reduction in mechanical friction, less viscous drag and through less resistance from windage.
These reductions in friction and drag that freed up an amazing 11% gain in power from our Civic’s K20A3 engine would have to get us gains in fuel economy as well. How much would the mileage increase? We would find out!
The EP3’s K20A3 engine is designed for low friction, low viscosity oil with the appropriate tight bearing clearances. The factory recommended oil viscosity is a thin 5W-20.
The Tundra has a recommended factory fill weight of 5w30. It is a heavy duty engine and still has the tighter clearances to run lower friction oils.
Since the Tundra is the MotoIQ workhorse we would get fuel economy reading in both normal driving and while towing.