Tachometer
The tachometer shows the engine speed in thousands of revolutions per minute.

Do not operate the engine with the pointer of the tachometer in the red zone. This may cause severe damage to the engine.
See also:
Limited slip differential (LSD) (STI)
The LSD provides optimum distribution of power according to the difference in revolutions between the right and left wheels that may be caused by certain driving conditions, thereby improving driving ...
Warning and indicator lights
...
Air conditioner compressor shut-off when engine is heavily loaded
To improve acceleration and gas mileage, the air conditioner compressor is designed to temporarily shut off during air conditioner operation whenever the accelerator is fully depressed such as during ...
