It's a bit more complicated but at least as it applies to the 318ti, you've got it mostly right. According to the '96 price list and BMW internal publications, AST was to become available during the '96 model year as an option on the 318ti, replacing LSD. Price list shows option #214 as $1,100 on a ti. It's questionable as to whether or not any cars were ever delivered with AST for '96 in the U.S. (anyone have one?) but it became standard on all BMWs including the ti (delayed on the Z3 1.9-only until 11/96 production) for the '97 model year.
ASC was the earliest BMW Traction Control system and was initially on only the 750iL in the U.S. ASC used only throttle modulation to contol differential in wheel speed during spinning as picked-up by the ABS sensors. In '91 with the introduction of the 850i, ASC+T (for Traction) was introduced which used rear wheel brakes to stop wheel spin. Also the system reacted much more quickly. The +T was standard on the 6-speed 850i and optional on cars that came standard with normal ASC like the 850iA and the 750iL and the normal ASC became avialable as an option on other M30 engined cars (535i, 735i/L). In 1994 ASC+T became the only traction control avialable on BMWs and they began to call it "All Season Traction" even if the button on the dash still said "ASC". ASC+T was an available option on all but the 318 models. By '96 it was standard on everything except the 318 models, 328s, and Zs. and standard across the board for '97 with the exception of the very earliest Z3 1.9 models for that year. Dynamic Stability Control came later on most cars but began on some 12-cylinder models as early as '95. |