Conventional wisdom would dictate that the growling, 416-hp IS-F signals some kind of directional change for the silky and mellow Lexus brand, but let us explain why this car does no such thing. One of the pillars of the Toyota Way is "No Waste," expressed in everything from its just-in-time supply chain to its legendary mandate that company executives sharpen their pencils all the way down to the erasers. And to Toyota, there are few things more wasteful than a car that doesn't sell. "No Waste" is why Toyota has made itself better than anyone at researching and testing and analyzing the widest band of customer preference in each segment, better at giving the people exactly what they want. Unlike most other carmakers, which are guided by internal engineering compasses and house style, Toyota is mainly a reactive enterprise, finding hot spots in the market and chasing after them like a terrier after a Grand Am. (Of course, Toyota being Japanese, there is a countervailing impulse, a Yang to the Yin - calculated risks like the Prius and the FJ Cruiser and the Scion brand. But these examples sit on the roadside of Toyota's march toward world domination, categories unto themselves.)

So I laughed obnoxiously in the hushed, dimly lit briefing room when Lexus's VP of marketing said, "The IS-F wasn't part of any carefully planned program. This car wasn't supposed to happen." As much as Lexus wants to think that the IS-F sedan is some fire-breathing aberration in its milk-safe lineup, it fully embodies the mercenary spirit of Toyota, Inc. Here, Toyota is in a particularly target-rich environment - the small and relatively high-volume end of the supersedan category, where the Audi RS4, Mercedes-Benz C63 AMG, CTS-V, and the originator, the BMW M3, lurk. Indeed, all this talk of working outside the system sounds like sandbagging, as if Lexus is managing the press's expectations relative to the competition: If these guys hadn't done their homework here, why would the IS-F eke out a 2-hp advantage over the M3?

Lexus could have shoehorned in the LS600h's 5.0-liter V-8 and transmission, popped in a limited slip, christened it the IS500, and called it a day. But to its credit, Lexus did more. The IS's V8 shares its architecture, VVT-iE variable-valve timing, and combination port/direct fuel injection system with the LS. Unique to the small car, however, is a head scavenge oil pump to keep the engine lubricated at high g loads; titanium intake valves with solid lifters; a low-friction, mirror-polished, hollow camshaft; and a dual-air intake system with a secondary port in the right front wheel well that opens up above 3600 rpm.

Unlike the somewhat predictable engine mods, the reprogramming of the LS's eight-speed automatic is unexpected and groundbreaking. The so-called 8-speed Sport Direct Shift gearbox has two modes: In D, the torque converter is engaged throughout all gear changes to smooth them out (and sap power and time), just as in a conventional automatic. But in manual M mode - controlled by either the gear lever or two blade-like paddles attached to the steering wheel - the converter only twists in first gear, multiplying torque for a fast launch; in gears two through eight the gearbox functions like a two-pedal manual, the torque converter's lock-up clutch providing a direct connection between throttle input and rear-wheel power. In this mode, the IS-F is the fastest-shifting manumatic on the road. It swaps cogs in 0.1 sec, faster than the F1 gearbox in the Ferrari F430, without much bucking or torque interruption - the thing even blips the throttle on downshifts. The ratios between gears three and eight are incredibly tightly spaced and short - to the extent that you question why, in a car with 371 lb-ft of flat torque, you should run through the middle ratios so quickly - but it's the small, stiff gears in this transmission that make such lightning-quick, unmassaged shifts possible. (Also, the Mercedes gearbox only has seven speeds.)

Lexus didn't neglect the IS chassis either, even if the changes here aren't as extensive as those implemented by the F's German competition. The front A-arm suspension has 90 percent stiffer springs and shocks than the IS350, with revised geometry to help mitigate brake dive. In back, the damping and springing rates are up 50 percent, but the rear toe-link bushings are more compliant than the 350's for better toe variation when cornering. Huge 14.2-inch drilled and vented Brembos with six pistons sit under the front wheels, with two-piston 13.6-inchers under the rears.

The sensors in those brakes enable a wide range of functions, bundled together in what Lexus calls Vehicle Dynamics Integrated Management (VDIM), which has three modes. Normal keeps traction- and stability-control on at all times. Sport ups the heft of the electronic power steering, raises transmission shift points, speeds throttle response, and relaxes the linear and lateral slip thresholds of the traction and stability systems. You can also turn the whole thing off - press the button with the sliding car icon once to kill traction control, hold it down for three seconds to snuff out stability control. In all modes, ABS and the electronically controlled brake LSD are always engaged.

Approaching the car, the first things you notice are the huge strakes aft of the front wheels. Then the powerful stance, and the way the turbine-like rims fill the wells. There's even a power bulge at the front of the hood, which makes the car look a little like a beluga whale. Inside, it's a four-seater: two heavily bolstered chairs up front, and a divided rear with a pass-through. There is woven-looking, aluminized composite trim on the center console and doors, and tastefully applied F logos (designed to mimic Turn One at Fuji) throughout.

We drove the IS-F on the sinewy roads of Central California and the dizzying elevation changes of Laguna Seca raceway. On the street, the car is quiet enough to be called Lexus-like, but the ride is anything but. The suspension is very tightly wound, and does not glide over road imperfections like the LS, or even the regular IS. But for all its firmness, the suspension has no rocking memory - no aftershocks scared me into thinking that the California coast was about to crumble into the Pacific. The pedal box is lively, too, with brakes that feel a tad jumpy and overservo'd, and a throttle that, thankfully, feels exactly the same way. The car tips into its power aggressively, and hustles seamlessly through the gears in Drive mode, more perceptibly in Manual mode. Lexus says this car sprints to 60 in 4.8 seconds and onto the quarter mile in 13 flat, but it has been tested at 4.2 and 12.7, respectively. The V8 isn't some high-revving Euro snob: it delivers its power like a howitzer and has the explosiveness and the upper-rpm shortness of breath of an old-school American V8. The sound is glorious, all fourth-order harmonics, and when the engine spins past 3600 revs and the secondary air inlet opens, the induction grumble intensifies to a roar. It's addictive. Less so is the steering, which returns more weight than pure feel. It moves off center with commendable linearity, but doesn't seem alive in your hands.

It's only on the track, with g loads in the tires, that the steering starts telling you all the front wheels' secrets. In fact, it wasn't until the IS-F hit dusty Laguna Seca, one of the most diabolical and undulating tracks in North America, that the car fully woke up. (It probably didn't hurt that the car's handling was developed here, as well as at Fuji, the 'Ring, and Paul Ricard.) The chassis is utterly stable through the twisting two-story drop of the famed Corkscrew, holding its line beautifully and shifting its weight expertly through the rest of Laguna's ascents and dips. The brakes are easy to modulate when you're deep into the pedal and they did not fade after two hours of hot laps - if these brakes were any better at retardation, they'd have their own show on Spike TV. But for all their power and all the fancy suspension geometry that tries to keep the front end from diving, there's no getting around the car's 3780 pounds or its 54/46 front weight bias. Under heavy, ABS-active, slam-you-into-your-seatbelt braking, the car's front loads up and the rear goes light and twitchy.

Speaking of weight, the ton of it up front means that you need to be patient with the car on turn-in - not Mustang patient, mind you, but the bow needs to be planted if you want to make your line and not understeer wide of it. If you go into a turn well set up but just a little too hot, however, VDIM helps. Its transitions between traction and stability control are invisible and its Sport mode does a superb job of allowing some slip angle while keeping you out of the gravel. On the track, VDIM is less satisfying in Normal mode, even though interventions are subtle, too. In Everything Off mode (also know as Holy Crap! mode), well, it's like driving on ice - a wide neutral phase soon becomes a large amount of oversteer. Even with everything off, the LSD does still help out a bit, providing some braking to a slipping wheel, and the coolest thing about this limited slip is that it can feed in brake and throttle at the same time.

The fact that this car is so capable, so fast, and so unflappable is a testament to the seriousness with which it was developed. It was shot like an arrow into one of the most competitive segments in autodom, and it can hang there. No, its chassis wasn't completely reengineered like an M car or even the new C63, but because the IS shares its architecture with the larger, V8-bearing GS, it gets away with it. Feelwise, the IS-F splits the difference between the bipolar M3 and the other parenthesis of the category, the C63, which is the very model of supersedan stoicism. It strikes its own elegant balance of the aggressive and the balletic, the stout and the playful. This car is better than it has any right to be when you consider it's within spitting distance, dynamically, of the race-bred giants in its segment. Moreover, this Lexus has the attention of all the Evo and STI drivers who, up until this car, have had no true Japanese supersedan into which to graduate. Add in that its price will undercut the M3 at an estimated $59,000, and you have a car that adheres to another precept of the Toyota way: "Be Late, But Be Great."