There have been three Z4 generations to date. The 2003 E85 immediately made an impact by being stiffer and more dynamic than its Z3 predecessor, which was a little soft for the tastes of many more ...

BMW Z4 35i vs Z4M Sound Battle Hear the difference 3.2L E85 vs 3.0L Turbo E89 Roadster ...

Class 1 is summertime E85, and needs to have a minimum of 79 percent ethanol (so even E85 doesn't have to be E85). Class 2's ethanol minimum is 74. And Class 3, wintertime ethanol, is 70 percent.