I drive a 02 accord coupe auto and whenever I have to wait those long lines for the left turns, I leave my tranny on neutral and wait for the green light to put it back to drive...is it okay to switch to neutral whenever i'm on a red light like I would for a stick? is that good for auto or bad?
also, how often do i have to change the spark plugs? i'm at 68k

 

i think it is fine to go from neutral to drive so long as you arent neutral dropping it.

 

I do that when the car is still warming up so it can warm up a little quicker. But as far as doing that at stoplights after it's warmed up it makes no difference, no help or hurt.
You only need to change your NGK platinum plugs at 105K miles.

 

leaving the car in gear does not hurt either.........

 

i put it on neutral because i believe it saves gas compared to putting it on drive on the long left-turn stoplights...is that right?

 

doesn't make a difference in terms of fuel economy.....