Sythetic oil got me 40mpg

[ardvark2175]

Bought a 2012 Yaris LE automatic. I was pretty much getting the advertised fuel economy of 32 / 35. The following service was done to the vehicle. 50 miles at purchase, installed K&N washable air filter. 500 miles, oil change standard Valvoline 5w30. 2500 miles, oil change with standard Valvoline 5w30. 5000 miles, oil change with Semi synthetic Valvoline 5W30, cleaned air filter. 10000 miles oil chance with full synthetic Valvoline 5W30, transmission flush with AMSOIL Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid. Immediately after going full synthetic I gained 5 mpg. I get 40 mpg regularly now driving the same 180 mile route driving 60 and 65. Just thought I would share. was pretty jealous of the 40 mpg guys, but am happy to be joining the club.