ok i found some facts for the engine on the net....
Two engines are available; both are inline six-cylinder engines. As the nomenclature indicates, 325 models get a 2.5-liter engine, while 330 models get a 3.0-liter engine. Wagons are only available with the 2.5-liter engine; sedan, coupe, and convertible are available with either engine.
The 184-horsepower 2.5-liter engine is used in the 325i sedan ($27,100); 325i sport wagon ($29,500); 325Ci coupe ($29,100); 325Ci convertible ($36,100).
The 225-horsepower 3.0-liter engine is used in the 330i sedan ($33,990); 330Ci coupe ($34,990); and 330Ci convertible ($42,400). In addition to the increased power, 330 models come with more standard equipment and design upgrades. One example: 17-inch wheels with V-rated tires in place of the 325's standard 16-inch wheels with H-rated tires.