In 1997 (1998 model year), both the SC 300 and 400 were upgraded with VVT-i and thus the ratings were raised to / of torque for the SC 400 and / of torque for the SC 300. Tests conducted on the new engines showed an acceleration for the SC 400 for years 1992–1995 of 0–60 mph in 6.9 seconds, years 1996–1997 in 6.7 seconds, and years 1998–2000 in 6.1 seconds. For the SC 300 an acceleration 0–60 mph in 6.8 seconds with the 5-speed manual and 7.2 seconds with the 4-speed automatic for all years. This 1997 upgrade included the replacement of the four-speed automatic on the SC 400 to a five-speed unit. With the replacement of the five-speed unit those models also got a new differential with a final drive of 3.27 improving both fuel economy and top speed.