To do so, Lexus unveils the GS400, powered by a 4-liter, 300-horsepower, 32-valve V-8 that will reach 60 miles per hour from a standing start in 6 seconds or less as about 80 percent of the torque kicks in at 1,800 r.p.m. Top speed is regulated at 149 m.p.h.30 Nov 1997