You'll see the letter M a lot in cars, especially those with a manual gearbox. It's there to indicate that the car is designed to be driven on petrol. It's usually followed by a group of letters that tell you more about the engine. For example, BMW M cars use a blue, violet and red color scheme with an M logo on the side. The M logo is a symbol of the company's motorsport success.
Most drivers of newer vehicles do not know what the M means in their cars. In fact, the M is a mode that can be activated in some automatic transmission cars. This mode can be used to give the driver more control over how their car is driven. It can also come in handy if the car's automatic transmission malfunctions - which is not uncommon.
If you are driving an automatic vehicle and have a M button on your gear shift, the first thing you should do is check your owner's manual. It should have specific instructions on how to shift your car into manual mode while you are driving.
Once you've done this, you should be aware that shifting up into higher gears will cause the engine to rev a lot more. This can be dangerous for the engine, so you should always release the brake and clutch when you're going up through the gears. It's also a good idea to warm up the engine before you start driving if you plan on going into M mode.