When I drive with shifter in "D", how do I know which gear I am in? Say I am driving at 40 MPH, tap the shifter once to the left and display shows "4". Does it mean I was and am in 4th gear, or I was in 5th now I am in 4th, since I tapped once?

I wish there is a displayed gear number to tell us which gear I am in when shifter is in "D".

 

Yes, you were in 5th gear before you tapped the shifter once to the left, which made you go into 4th.

 

Thanks. I knoe I will get answers. So I think I have been in 5th gear for most times when I am driving around on city streets.

 

You are indeed mostly in 4-5th gear around town. Even my old 4 speed Pontiac is smart enough to stay in third below about 70kph.

HTH