Lexus’s next-generation 5.0-litre V8 will debut with the new RC F when it goes on sale in February next year and it will become the first non-hybrid vehicle in the world to utilise the Atkinson cycle when there’s limited demand for power and torque.
Although from the outside it may look and sound like the same engine as the one found in the outgoing Lexus IS F, which launched all the way back in 2007, Lexus says its F engine is almost entirely new.
Speaking with CarAdvice at the launch of the new Lexus RC F in New York last week, the chief engineer of the RC F program (who was also in charge of the IS F), Yukihiko Yaguchi, said everything about the 5.0-litre V8 in the RC-F “except the engine block is brand new”.
The new V8 develops 351kW of power and 550Nm of torque, allowing the RC F to accelerate from 0-100km/h in 4.4 seconds. Its sprint time leaves it trailing the recently launched twin-turbo BMW M4 (4.1 seconds) and the soon to be replaced Mercedes-Benz C63 AMG (4.2 seconds in the 507 Edition).
Asked why Lexus remained with the same naturally aspirated V8 engine, Yaguchi said the 5.0-litre met all of Lexus’s needs for the RC F.
“[We] increased the horsepower but at the same time were able to convert it in Atkinson mode [so] we were able to gain in the efficiency as well and then without downsizing we were able to make sure there was sufficient torque with the 5.0-litre engine,” he said.
As for turbocharging the V8 for extra power and improved efficiency, Yaguchi said he doesn’t believe turbocharged engines deliver the type of linear power delivery that is required for an F model.
“[I] don’t think that the current turbo [powered performance cars] is delivering the kind of linearity we are looking for.”
Read CarAdvice's Lexus RC F Review.