Engines
The first two generations (240Z/260Z/280Z and 280ZX) of Z-car were powered by a Straight-6, (part of the L-series of Nissan engines, which powered most of their vehicles until the early 1980s) with a displacement of 2.4 L in the first incarnation, and increasing to 2.6 L and 2.8 L in the 260Z, and the 280Z and ZX, respectively.
The second generation, the 280ZX, introduced in 1979 was a complete re-design, retaining only the L28 engine and other driveline components. A turbo option was introduced, bringing performance surpassing that of the original 240z.
The third generation, the 300ZX, switched to a 3.0 L V6. Two generations of 300ZX ended in 1996 in the US{in most states, anyway} and the Z32 model canceled in Japan in 1997{Some cars were still exported there, though}. The cost of production was rising too fast for Japanese and most U.S. customers, so it was limited to those states in which could be sold. Even a major design change in 1998 couldn't save it, and production finally ended in 2001.
In the 2003 model year, Nissan reentered the US sports-car market with the 350Z, powered by a 3.5 L V6, and styled in an attempt to create a more modern interpretation of the 240Z's lines. It had a new 6-speed manual gearbox, and is capable of over 155 mph.