432 Q18 LTC Engines

Diesel Exhaust Fluid (DEF) is used to treat

• NOx

• CO

• soot

• all CIE emissions

(Brain Builder) Selective Catalytic Reduction (SCR) forces the CIE to operate near stoichiometry.

• True.

• False.

GCI engines have higher compression ratios than SIEs.

• True.
• False.

GCI engines run primarily on diesel because it autoignites faster than gasoline.

• True.
• False.

The fresh charge in GCI engines is

• air only.
• fuel only.
• fuel-air mixture.
• air + residual gases.

A gasoline-air mixture will autoignite if compressed with a high enough compression ratio.

• True.
• False.

Volumetric autoignition means

• autoignition is triggered by low volumetric efficiency.
• the entire clearance volume autoignites simultaneously without a flame front.
• heat released per unit volume.

Volumetric autoignition is a form of engine knock.

• True.
• False.

GCI engines run stoichiometrically like SIEs.

• True.
• False.

Super/turbocharging is optional but recommended in GCI engines.

• True.
• False.