this was always so confusing to me...and recently i saw someone on the forums that asked the question i had once asked...it was fun to see someone else trying to understand what ended up being a really simple thing...
Originally Posted by mdwman 
\\what do the different designations (318, 320, 323, 325) represent? Mark
the 3 is for the series in the lineup of BMWs. the others being the 1, 5, 6, 7, Z, ect.
the next group ie; 23, 18 ect. is the size of the engine in liters. 23 is a 2.3 liter 6 cylinder and the 18 is a 1.8 liter 4 banger.
the next letter tells more about the car. if there is a "I", it's means fuel injected, "CSL" is coupe sport lightweight, "e" is something greek? for eta or low rpm - high torque.
if there is a "s" after that, it's has a sport package. a "x" is all wheel drive.
