2009 Audi TT Coupe — Owner's Manual
The engine turns at a speed 1,000 times the single digit in the display, e.g. if the needle is pointing at the "2" the engine is turning at 2,000 RPM. If engine RPM drops below 1,500, you should downshift to the next lower gear. The red area at the end of the scale indicates maximum permissible engine RPM after the break-in period. Before reaching this area, shift into the next higher gear (manual transmission), move the selector lever to position "D (Drive)" (automatic) or ease your foot off the accelerator pedal.
The tachometer needle should not move into the red range. If it does, then only for a very short period of time. You could damage your engine by driving at high RPM. Engine cold: as long as the needle remains at the left end of the gauge, the engine still has not reached its operating temperature.
Avoid high engine speeds, heavy engine loads and heavy throttle. Normal temperature: when the engine has reached its operating temperature, the needle will move into the middle of the gauge and remain there. If the engine is working hard at high outside temperatures, the needle may turn further to the right. This is no cause for concern as long as the warning light in the instrument cluster does not illuminate.