To some, the 2011 Lexus IS F represents the company's response to other carmakers' performance divisions. To others, it shows what might happen if your teenage son absconded with your Lexus IS and your platinum credit card. Either way, only the exotic Lexus LFA sports car sends a stronger high-performance message for Toyota's premium brand than the 2011 Lexus IS F.

Now in its fourth year of production, the IS F receives an array of high-performance hardware, including a potent 416-horsepower V8, bigger brakes, a suspension that's calibrated for aggressive driving and sticky performance tires on 19-inch wheels. Styling comes next, with a meaner front fascia, a bulging hood, wide fender flares, low-slung rocker-sill skirts, quad exhaust pipes and a rear spoiler. Needless to say, the IS F doesn't look like any other Lexus model.

Previously, this production tuner car lacked the type of refined ride quality that the luxury brand is known for. Unless you were driving on glass-smooth pavement, the IS F felt harsh and unyielding, even when compared to cars that offer similar performance. But the 2011 IS F receives some serious tweaks to take the edge off. Thoroughly revised suspension tuning has greatly reduced ride harshness, and last year's uncommunicative electronic-assist steering has been helped by retuning for 2011. There's also a new mechanical limited-slip rear differential that replaces the previous electronically controlled unit for improved traction.

A couple faults still remain, including a relatively cramped passenger compartment and the lack of a manual transmission option. But thanks to this year's changes, the 2011 IS F is now finally a worthy match to other super sport sedans like the 2011 BMW M3, 2011 Cadillac CTS-V and 2011 Mercedes-Benz C63 AMG.

The 2011 Lexus IS F is a high-performance luxury sport sedan that is offered in a single well-appointed trim level.

Standard features include 19-inch alloy wheels, Brembo brakes, a limited-slip rear differential, a sport-tuned suspension, bi-xenon headlights, LED daytime running lights, a sunroof, keyless ignition/entry, auto-dimming mirrors, eight-way power heated front leather sport seats with memory settings, suede seat inserts (black leather only), dual-zone automatic climate control and a 13-speaker audio system (with satellite radio, Bluetooth audio, a six-disc CD changer, iPod integration and an auxiliary audio jack).

A hard-drive-based navigation system with a back-up camera, real-time traffic and weather updates is optional. Also available is a 14-speaker Mark Levinson surround-sound audio system (requires purchase of the navigation system), front and rear parking sensors and adaptive cruise control. Navigation-equipped vehicles come with a one-year subscription to Lexus' Enform, which provides on-call travel advisers who can help drivers with destinations (e.g., a movie theater or the closest gas station) and then send the info to the navigation system.

The rear-wheel-drive 2011 Lexus IS F is powered by a 5.0-liter V8 that produces 416 horsepower and 371 pound-feet of torque. An eight-speed automatic with a manual mode and shift paddles on the steering wheel is the only transmission offered.

In Edmunds testing of the Lexus IS F, the car accelerates to 60 mph from a standstill in a brisk 4.8 seconds. EPA fuel economy estimates are 16 mpg city/23 mpg highway and 18 mpg in combined driving.

Standard safety features for the 2011 Lexus IS F include antilock brakes with brake assist, stability control, traction control, front-seat side airbags, front knee airbags and full-length side curtain airbags. A one-year complimentary subscription to Safety Connect, which provides collision notification, stolen vehicle location and an "SOS" emergency help button is also included. A pre-collision system is also available with the optional adaptive radar cruise control that senses an impending collision and automatically adjusts seatbelt tension and braking force.

In Edmunds braking tests, an IS F came to a stop from 60 mph in a short 112 feet.

The 2011 Lexus IS F is as exciting to drive as advertised. The powerful V8 roars when prodded and has no problem laying waste to the rear tires in a torrent of white smoke (with the traction control disabled, of course). Even when cruising, the constant low baritone exhaust tempts you to feed in more and more throttle. The chassis is capable of managing the abundant power, with high levels of cornering grip and precise steering. Traditionalists will bemoan the lack of a manual transmission, but the eight-speed automatic proves worthy with quick upshifts and rev-matched downshifts. Unfortunately, eight gears sometimes seems like a couple too many, as the transmission occasionally hunts too much for the right one.

In prior years, the IS F rode too stiffly even for this class of car, making it hard to justify for everyday driving. This year's suspension changes are a welcome improvement, as the car is much more livable on city streets and freeways. The steering also feels more natural. The 2011 car still has a slightly firm ride, though, and notably the adaptive suspensions on the M3 and CTS-V help make those cars superior for dual-purpose use.

Much like the supporting IS models, the 2011 Lexus IS F features a quiet cabin, well-placed controls and top-notch materials. Unfortunately, the IS F also suffers from the same drawbacks in the form of limited space. Headroom and rear legroom are at a premium, which might prove problematic for taller occupants. The trunk can hold a maximum of 13 cubic feet of luggage, which is about average for cars in this class.

The IS F differentiates its interior from its more sedate IS stablemates by utilizing sporty accents and features. The front sport seats are the most notable upgrade, with added side bolstering and racy suede inserts. The IS F's rear seat is set up to only accommodate two passengers instead of the normal three. Other sporty touches include aluminum trim (instead of wood) and cool, blue ambient lighting.