The IS 500 F Sport Performance is said to "up the sports sedan formula to eleven" but, like all other versions of the recently refreshed saloon, won't be sold in the UK.
The powertrain is familiar, however, being lifted from the RC F coupé that was on sale here until last year and related to the slightly downtuned unit available in the LC 500 grand tourer.
The new sports saloon will be one of just a handful of new cars sold with a naturally aspirated V8. Sending 466bhp and 395lb ft to the rear axle through a Sport Direct Shift eight-speed automatic gearbox, the 5.0-litre unit endows the range-topper with a substantial performance boost over the 3.5-litre V6-powered IS 350.
The IS 500 weighs just 62kg more than the six-cylinder model, at 1765kg, so the 149bhp power hike gives a 0-60mph time of just 4.5sec – a 1.2sec improvement. Fuel economy, as is to be expected, takes a hit, though: down from a claimed 28mpg average to an estimated 24mpg.
Lexus is keen to emphasise the character of the motor as much as its performance capability, describing the quad-exhaust system's soundtrack as "ferocious" and "throaty" and likening it to the sound of the RC F.
The IS 500 F Sport Performance can be driven in two preconfigured modes: Sport S and Sport S +, which boosts engine response and tweaks the steering and suspension for "sportier handling to match the updated powertrain settings". An adaptable Custom Mode offers different combinations of characteristics from the car's Normal, Eco and Sport settings.
The new IS is said to signal a shift in focus for Lexus engineers to "elevating vehicles to a new standard of performance and handling". The ultimate goal, it says, "is to deliver a new generation of Lexus vehicles that is more balanced, refined in control, and confident than ever before".
In line with that ambition, the IS 500 comes as standard with a Dynamic Handling Package that brings adaptive variable suspension and a limited-slip differential for enhanced grip during cornering. Additional tweaks over the IS 350 include the addition of Yamaha-developed rear dampers, which are claimed to improve low-speed refinement and high-speed stability, and larger brakes with improved cooling.
The IS 500 can be told apart from the IS 350 primarily by its raised bonnet, extended front bumper (made necessary by the bigger powerplant), bespoke 19in lightweight alloy wheels and unique rear bumper design with twin-stacked exhaust exits at each side. The new F Sport Performance badging is painted black, rather than silver.
The interior is similarly marked out from the standard car with unique badging throughout and a bespoke start-up animation for the infotainment display.