The IS series is crucial to Lexus maintaining any sort of sport sedan credentials; Toyota's luxury arm announced it was killing off the GS midsize sedan at the end of the 2020 model year. But the compact sports sedan remains a necessary segment for a luxury automaker to prove its worth—especially when new entrants such as the Genesis G70 and Alfa Romeo Giulia have won theMotorTrendCar of the Year honors for furthering the concept of what the BMW 3 Series seemingly perfected years ago.

Lexus has done some work to the sheet metal and what's underneath it, but as we've previously reported, the 2021 IS is not an all-new product but rather an upgrade to the existing car, which was already face-lifted once in 2016. This means it continues to ride on the New N platform it rode on back in 2013, rather than migrating to Toyota's New Global Architecture-L luxury car platform. Let's hope this is merely a pause to further develop a next-generation IS arriving in a few years, rather than a last gasp before surrendering to the fates.

Engineers focused on stiffening the existing chassis to reduce vibration and flex with new reinforcements on the C-pillars and radiator side supports and adding more welds to the front side member supports. From there, they moved on to the suspension, which received 20 percent lighter coil springs, 18 percent lighter control arms (now made of aluminum), and new anti-roll bars (made of an undisclosed material) which helps reduce the weight by 17 percent. They even went so far as to steal a trick off the LFA supercar and replaced the traditional wheel studs and lug nuts with wheel bolts, which save 2.2 pounds total and are both stiffer and stronger.

Lexus will bolt new standard 18-inch wheels to the hubs, up from 17 previously. Lexus will also offer 19-inch wheels for the first time, both for pleasure and performance. Special BBS 19-inch wheels will be available on the IS 350 F Sport and are noticeably lighter than the other 19-inch wheel option.

For the suspension, Lexus has fitted its new swing-valve shock absorbers, which add a second valve tuned specifically for small movements. This allows the engineers to tune the primary valves for the big suspension moments while using the secondary valves to maintain ride comfort over the little road imperfections. Adaptive Variable Suspension, with electronically controlled shock absorbers, is available on the IS 350 F Sport with the Dynamic Handling Package only.

All of this updated hardware has been tuned at the new Shimoyama R&D facility in the mountains outside Toyota City. With its Nurburgring-inspired test track, Shimoyama is designed to develop the sportier "Lexus Driving Signature" for all future models, starting with the new IS. So important is this new metric every Lexus will have to be approved by the president of Lexus, Koji Sato, as well as Akio Toyoda—the rare automotive CEO as comfortable on the racetrack as the boardroom.

For the real driving experience, though, you'll need that F Sport package, which is now only available on the IS 350, but with rear- or all-wheel drive. A unique front bumper and grille allow for larger brake cooling ducts than the standard car, while a cold air intake and a sport exhaust dial up the sound (but not the performance), which is then enhanced by the stereo speakers. A piano-black trunk spoiler and faux rear diffuser pair with rocker extensions to complete the look.

Inside, looks are augmented by heated and cooled sport seats with more adjustments, unique door card trim, metal pedals, a perforated leather shift knob, heated leather steering wheel, stainless steel door sill plates, and a sportier instrument cluster.

For mechanical enhancements, though, you need to spec the Dynamic Handling Package as well. In addition to the active shocks and lightweight wheels, it adds a Torsen limited-slip differential to rear-drive IS 350 F Sports. There are also two extra drive modes, Sport S+ (the most extreme) and Custom (driver programable). You also get a carbon-fiber trunk spoiler and mirror caps, plus Silver Ash steering wheel trim.

Under the hood, things are more familiar. Engine choices are unchanged, with the IS 300 retaining the turbocharged 2.0-liter I-4 as the base engine with 241 hp and 258 lb-ft connected to an eight-speed transmission powering the rear wheels. The IS 300 AWD soldiers on with its detuned 3.5-liter V-6 making 260 hp and 236 lb-ft and turning the same old six-speed automatic en route to all four wheels. The IS 350 continues with its 311-hp version of that 3.5-liter V-6 and 280 lb-ft, running an eight-speed automatic with rear-drive and the six-speed automatic with all-wheel drive.

Lexus designers have performed a bit of cosmetic surgery on all sides. In front, the spindle grille's sharpest edges have been toned-down a bit as it takes on a less spindly shape. Even more notably, the headlights have been reworked to move the DRL swoosh back inside the headlight housings. LED headlights are optional.

Around back, the previously droopy taillights have been tightened up and are now connected across the trunk lid in one nearly unbroken beam. Below, the lower bumper has been pumped up and the reflectors and exhaust tips have been slimmed down. On the sides, Lexus has pumped up the fender flares to accommodate the larger wheels and a dramatic tuck under the C-pillars gives the car unmistakable hips. Between the wheels, sharp creases can't decide whether they want to be straight lines or curves as they appear and disappear seemingly at random along the rockers. Overall, Lexus claims the car is more aerodynamic, though any effect it may have on fuel economy remains to be seen.