$7.$ What impact does reducing the engine's internal friction have on performance?

$-$ A$)$ Decreases the engine's power output

$-$ B$)$ Increases the engine's fuel consumption

$-$ C$)$ Improves the engine's efficiency

$-$ D$)$ Reduces the engine's thermal efficiency

$8.$ Which factor can negatively affect the brake mean effective pressure $($BMEP$)$ of an engine?

$-$ A$)$ Higher compression ratio

$-$ B$)$ Increased turbocharging

$-$ C$)$ Poor fuel quality

$-$ D$)$ Improved lubrication