Certain automatic cars have a D3 written on the gear shift, often found directly below or to the right of D. It's probably something you always skip over and never really thought about while running ...

No vehicle, not even your own feet, can take you farther with less energy than a bike. And when a bike has multiple gears-two or three chain rings up next to your pedals and up to 11 cogs on your back ...

When did you last think about what goes on under the hood while cruising down the freeway in your trusty automatic ride? As you relax and enjoy the open road, the intricate dance of gears is probably ...