on automatic civics, what do D3 and 2 do? i notice when i put it in '2' it just didnt shift at all. just curious

 

I'm not sure what they do, seeing as I drive a manny, but my van's (Honda Odyssey) manual says to use them when towing or going up steep hills and stuff like that.

 

it keeps it from shifting up. if you put it in 2, then it locks it in 2nd gear, so it will be slow as hell on the low-end, as you wont have first.

 

It's actually for carrying heavy loads. If you going to tow or carry some REALLY heavy , that's what you'd use. It actualy utilizes more horsepower and torque out to your engine(if you have any). That's why if you try shifting in an automatic when you race, you'll actually loose speed, because the engine uses the horsepower, not the speed.