Overdrive should stay on (light off) all the time for best fuel economy

Overdrive off (light on) means you are limiting the maximum gear to 3rd gear and it won't engage 4th gear (for old vios gearbox)

Of course you can do both for your "normal drive" vios gearbox is very hardy, you can literally throw it around and it still work

Car owners nowadays don't read the user manual or even Google?

This post has been edited by amduser: Jan 11 2017, 05:36 PM

I did Google before because my previous car is vios too