Transmission Mystery!

"S" mode is sport shift mode, it allows you to manually shift the auto transmission. However, it basically means you can set the highest gear the transmission will up shift to. It will always downshift and up shift automatically based on the highest gear you select. For example, if you set "5" you now have a 5 speed auto transmission, if you set "4" you have a 4 speed auto transmission, etc. I have found that on the Auto Transmission, that 6 gear is way to high. And as others have experienced, it constantly shifts between 5 and 6 even on flat roads at the slightest headwind and incline. When I use "S" mode, I set "5" so that 5th is tyhe highest gear the transmission uses. I have noticed much better performance and better MPG this way (about 1.2 mpg)

5th gear and 6th gear are both overdrives. Toyota added 6th to try and get the MPG up, which may work okay in the lab and dyno, but not in real world conditions.