The reengineered 2021 Lexus IS sport sedan will offer improved handling and responsiveness with an upgraded suspension, plus newly enhanced safety and infotainment functions. However, the premium brand’s sporty compact will stay on its current third-generation platform — which dates from the 2014 model and was last freshened in 2017 — instead of being redesigned onto the automaker’s global architecture.

In addition to cost savings, keeping the IS on its current platform allowed Lexus engineers to focus on improvements to the sedan’s ride and handling, as well as make styling and interior refinements. The new IS is just over an inch longer and wider than the outgoing model, with a slight increase in height as well. It will now ride on standard 18-inch wheels, with optional 19-inch wheels available.

Sales of the IS in the United States were down 37 percent through May to 4,313, with the decline exacerbated by the COVID-19 pandemic. However, in 2019, its U.S. sales were off 35 percent to 14,920.

The updated 2021 IS was scheduled to debut at the New York auto show in April but was instead revealed online Monday.

The big investment in the reengineered car is in its body structure and suspension. Engineers reinforced a number of points to improve body rigidity and revised the suspension layout and front pickup points to accommodate larger tires and wheels. They also focused on removing unsprung weight to enhance handling, employing lighter weight hub bolts, lighter coil springs, forged aluminum A-arms and a new suspension stabilizer bar to deliver a lighter, more nimble suspension setup.

Styling is still dominated by a massive spindle grille, now featuring a newly designed three-dimensional polyhedral structure with mini spindles within the design on standard models and a block form mesh variation on the F Sport model. The headlamps were made more slender and feature daytime running lights with a sharp L-shape signature above, a motif that carries through to the new blade-style light bar that stretches across the back of the sedan.

Inside the cabin, the 2021 Lexus IS features a standard 8-inch touch screen infotainment system that has been moved 3 inches closer to the driver to aid access. Models equipped with navigation or the upgraded 17-speaker, 1,800-watt Mark Levinson audio system will come with a 10.3-inch touch screen. Both screens are compatible with Apple CarPlay, Android Auto and Amazon Alexa integration.

Under the hood, the IS will offer either rear-wheel or all-wheel drive. The base IS 300 is powered by a 2.0-liter I-4 engine mated to an eight-speed automatic transmission delivering 241 hp and 258 pound-feet of torque. The awd version of the IS 300 is powered by a 3.5-liter V-6 engine mated to a six-speed automatic transmission, delivering 260 hp and 236 pound-feet of torque. The upgraded IS 350 comes equipped with a 3.5-liter V-6 delivering an uptuned 311 hp and 280 pound-feet of torque, with an eight-speed transmission in the rwd model and a six-speed transmission powering the awd model.

The Lexus IS F Sport package will now be available only on the IS 350 model.

The 2021 Lexus IS will come equipped with Lexus Safety System+, the brand’s suite of standard crash-avoidance and driver-assist systems, including lane-keeping assist, dynamic radar cruise control, road sign assist, automated high beams, automatic emergency braking, frontal collision warning and newly enhanced frontal camera and radar systems with extended response ranges.

Pricing for the 2021 Lexus IS was not announced. However, the vehicle is supposed to be in Lexus’ 242 U.S. dealerships in late fall.