If you bought a new car and are confused what the "M" means on or near your gear shift, don't worry. Here's what is, what it does, and when to use it.

Get your car to around 20 to 25 mph before you shift to D3. At this point, slightly let off the gas when you shift. If you don't, you may damage the transmission.

When you put your car in D3, that means you've set third gear as your highest setting, whereas you can reach every gear of your car in D. Basically, D3 is used when you're driving uphill, downhill ...

It's a frustrating experience to attempt putting your car into gear, but having nothing happen. There are a few possible explanations for what's going on.

If you click that button, it'll lock out the highest gear. This can help when you need your car's full power to accelerate for passing, climbing a hill or pulling a trailer, J.D. Power says.

Throwing your car in neutral allows you to push it around, which is real handy if, say, your battery's dead and your car won't start or you break down in traffic.