Having driven manual trans for most of my life - I'm at a loss as to the purpose and correct use of the overdrive button in my 2011 Hyundai Accent. The supplied manual had little help.
After six months of driving with the recommended 'overdrive on' I was unhappy with mileage. The guys at the dealership had different opinions. One man even told me 'overdrive off' was for aggressive driving which did not appeal to me. I could not get an answer that satisfied me so I experimented. Driving in stop and go seemed great after I 'turned off' the 'overdrive' button. Then I headed up on the interstate and the car sounded and felt like I was traveling 50 in 3rd gear. I immediately turn the overdrive back on and it settled into it's normal hum.
So - decided to research fuel efficiency and here I am. Most answers other places suggest to always leave button 'on' yet another said while driving smooth hills to turn it off.
I just want the best mileage - and the least wear on car.
Thanks