This makes one very big assumption - that the engine can overcome the drag that is created at this speed. The top speed involves the power curve of the engine (as a function of road speed in any gear) overlayed with the corresponding drag as a funciton of MPH. Given that the S2000, like any roadster is not exactly "clean" aerodynamically, there is a very strong possibility that the S2000 will not hit its red line in fifth because the drag exceeds the engine output before this speed is reached. Given the very peaky nature of thuis engine (good torque and power produced only at the top end) it ccould very well hit its maximum speed in fourth and not fifth.