432 Q8 Performance

Engine stresses and vibration scale with

• mean piston speed
• engine rpm only
• displacement volume
• stroke volume

Indicated mean effective pressure =

• indicated power per unit displacement volume
• the instantaneous pressure inside the cylinder
• the peak pressure inside the cylinder
• fuel consumption per unit indicated power

There is nothing called friction mean effective pressure.

• True.
• False.

When you talk to friends about a variety of big and small engines in the market, it is more accurate to use

• brake power
• brake mean effective pressure

Specific fuel consumption = fuel consumption per unit _________.

• power
• displacement volume
• engine weight
• intake-air mass

(Brain Builder) If I want to describe how efficient an engine is, I can use the specific fuel consumption.

• True.
• False.

Using more excess air should guarantee complete combustion in SIEs, but in reality the engine becomes less economic (high sfc), because

• the spark plug misfires.
• the fuel does not evaporate.
• the fuel does not mix with air.
• the fuel injector is faulty.