According to the search results, the top speed of a Toyota Supra MK4 is electronically limited to 160 mph (257 km/h) . However, if the limiter is removed, Toyota claims it can reach nearly 180 mph (290 km/h) . There are also some videos on YouTube showing a Supra MK4 reaching speeds of 164 mph (265 km/h) and even 177 mph (285 km/h) . Its important to note that these speeds were achieved on unrestricted sections of the Autobahn in Germany, and its not recommended to attempt to reach these speeds on public roads.