I was just explaining to him in simple ways.
I also know that OD off will not help in hilly areas like climbing natliagali road because on that roads any auto have to climb in 1 or 2nd gear. For which L or 2 is recommended to lock gear.
In D or 3 it will still upshift to 3 or 4 gear when throttle is left.
Many people have zero understanding of auto transmission. They just put it in D and drive. I know about the complete concept of D, Over drive, 3, 2 and L.
4 speed auto On Motorway 120km/h in final gear is around 3000rpm.
If OD OFF is on it will shift to 3 gear and certainly rpm will raise to 4000-5000rpm.
Agree on the use of OD for engine braking but On downhill L or 2 will provide more braking than OD beacuse being in lower gear like 1 or 2 when speed is between 20-50km/h usually in hilly areas.
Or ye be bilkul sahi bat ha ke log bas fazool batien sun lete he ke manual charyi pe achi ha or auto bekar. But I find auto more practical because there no clutch is involved just put in L or 2 according to speed and enjoy best possible acceleration.
Drove my 1.0L Vitz in L gear on some steeps of natayagali with 5 person and people were struggling with their 1300 Corolla and city.