GAS-EXCHANGE CONTROL
Although throttle-valve control represents the primary method of regulating the primary method of regulating the flow of fresh air into the engine, a number of other systems are also capable of adjsuting the mass of fresh and residual gases in the cylinder.

GASOLINE
Fuels for spark-igniton engines are basically hydrocrabon compunds, but can also contain oxygenous organic compounds or other additives for improved performance. The basic classes are regular and premium fuel, with th latter having enhanced knock resistance for use in high-compression engines.

GASOLINE ENGINE
The spark-ignition or Otto-cycle1) powerplant is an internal-combustion(IC) engine that relies on an externally-generated ignition spark to transform the chemical energy contained in fuel into kinetic energy.

GASOLINE FUEL-INJECTION SYSTEM
The gasoline fuel injection and the ignition are what get the engine running. The gasoline is injected into the intake manifold onto the engine's intake valves. The resulting air/fuel mixture is drawn into the combustion chambers when the pistons move downwards. When they move back up again, the A/F mixture is compressed and at the ignition point ignited by a spark generated by the spark plug. The resulting combustion energy forces the piston downwards and via the conrod the piston's linear motion is converted to crankshaft rotation.

Ground Effect
The phenomenon that occurs when the airflow between a moving object and the ground creates downforce.

GROUP INJECTION
Group injection combines the injectors in two groups, with each group being triggered ounce per cycle. The time interval between the two triggering points is equal to one crankshaft rotation period. This arrangement makes it possible to use the engine operating point as the essential criterion in selecting the injection mode while also preventing undesireable spray through the open intake valves throughout a wide range in the program map.