Although the IS-F shares its basic suspension with more mainstream IS models – double wishbone suspension at the front and a multi-link arrangement at the rear – Lexus has undertaken some serious tinkering to give the IS-F greater control.
The front suspension arms and steering knuckles are now constructed from lighter materials to reduce unsprung mass, the spring rates are increased, the anti-roll bars are thicker and the bump stops activate earlier, while the hub bearings are unique to the IS-F.
As expected for a sports model, the IS-F wears thicker and broader brakes (360mm at the front and 345mm at the rear), but unusually for a car with such driver-focused intentions, the IS-F employs electric power steering, and not a hydraulic system.
On first inspection the driveline package seems familiar, the 5.0-litre V8 providing the conventional power in Lexus’s range-topping Lexus LS600h hybrid. The eight-speed automatic transmission has also been seen before in the LS460 and GS460. Make no mistake, though, there has been some major tweakery. The result is a maximum output of 417bhp, 28bhp more than the LS600h, although torque slips slightly to 372lb ft.
The automatic gearbox in the IS-F benefits from bespoke ratios and a manual mode, operated either by the gear selector or paddles mounted behind the steering wheel. From second gear upwards the ’box operates a lock-up mechanism to give faster shifts and a more direct throttle response. It will also hold on to gears right to the rev limiter and only change down if the engine threatens to stall.