We hit the track in Lexus' new 3-Series fighter.

Things are starting to change at Lexus, and the 2014 IS sedan is clear proof of that.

After years of focusing on things like supple leather seats and vault-like quietness, Lexus set a different goal when designing the 2014 IS - make the sports sedan the most fun-to-drive vehicle in the segment.

And to prove it's serious about this whole fun-to-drive thing, Lexus invited us to sample its latest IS range again, this time at the Michigan International Speedway.

Detailing the changes

Completely redesigned for the 2014 model year, the IS now rides on a version of the Lexus GS platform. There is not shortage of technical details about that architecture swap, but the highlights include a larger front stabilizer bar that reduces body roll and a new multi-link rear suspension that improves tire grip. Oh, and the 2014 IS is the first-ever Lexus sedan to have a 60/40 split-folding rear seat.

Lexus' redesign efforts were clearly focused on the IS' chassis as the sedan's engines carryover for the 2014 model year. A 204 horsepower 2.5-liter V6 is standard in the entry-level IS 250, while the step-up IS 350 uses the same 306 horsepower 3.5-liter V6 as the previous model. Both the IS 250 and IS 350 come with rear-wheel drive but can be paired with all-wheel drive.

An F Sport package is new for 2014 (and available on all models), offering a unique body kit, sports seats and a tuned suspension. IS 350 rear-wheel drive models fitted with the F Sport package also receive a sportier S+ vehicle setting and an instrument cluster inspired by the LF-A supercar.

On track

So, does all that add up to the most fun-to-drive car in the segment? Well, that depends on the badge on the back.

The IS 250 is a fine handling car, but its fun factor is let down by a lack of power. We're all for the thrill of driving a slow car fast, but the small V6's 184 lb-ft of torque simply feels overwhelmed by the car's near-3,500 lbs. curb weight. The 200 lbs. weight penalty of the optional AWD system only exacerbates the problem.

We can't help but think that the IS 250 would be better served by a turbocharged four-cylinder.

Fortunately, the IS 350 corrects the 250's main drawback with a larger displacement V6.

Like the entry-level IS 250, the IS 350 corners remarkably flat, exhibiting just a touch of understeer at the limit. AWD cars tend to plow just a hair more.

We came away impressed with the IS' high-speed cornering ability, especially compared to the last-gen car, which tended to wallow when pushed. Steering is also much improved in the 2014 IS, delivering a good blend of road feel and weight.

When paired with AWD the IS 350 uses a six-speed automatic, but we prefer the eight-speed unit in the IS 350 RWD as it lends to better power delivery. The eight-speed - which is taken straight out of the IS-F - also boasts a rev-match feature.

The IS 350's - and the 250's, for that matter - brakes held up lap after lap without fade.

Although a solid improvement over the IS 250's engine room, there were times when we wished the IS 350's 3.5L had a bit more oomph. During day-to-day driving we doubt the IS 350 will leave you wanting for power, but Lexus had us test the IS on a racetrack, not the morning commute.

Leftlane's bottom line

After two generations of also-ran status, the 2014 Lexus IS is ready to go toe-to-toe with the segment's heavy-weight, the BMW 3-Series.

Although a bit too tepid in IS 250 form for our tastes, we'd be happy to park the IS 350 in our own garage - especially in rear-drive F-Sport guise. If you happen to be shopping for a compact luxury sedan, you'd be doing yourself a disservice by assuming the IS is just another boring Lexus.

2014 Lexus IS base price, $36,845.

Words and photos by Drew Johnson.