Crossovers and SUVs may currently have America's heart, but the modern midsize sedan segment is still a fiercely competitive class. And while some automakers have chosen to 86 their sedans altogether, other companies are still dedicated to producing quality, five-passenger four-doors that are stylish, comfortable and affordable. We've driven a lot of great midsize sedans here at Roadshow, but none speak to us quite like the updated -- and now, turbocharged -- 2018 Mazda6.

Turbo punch

While lower Mazda6 trims continue to use a naturally aspirated 2.5-liter I4 engine, the upper-crust Grand Touring and Signature models get a big increase in power. The turbocharged 2.5-liter I4 is essentially the same engine you'll find in the Mazda CX-9 crossover, and under the hood of the Mazda6, it makes this sedan move.

Step on the accelerator and the Mazda6 comes to life with a quickness. The six-speed automatic transmission fires off smooth shifts, letting the engine rev in its sweet spot to deliver the full 250 horsepower and 310 pound-feet of torque. Despite using front-wheel drive, the Mazda6 is free of torque steer, and in fact, the revised suspension tuning means this car is even better to drive than before; leave it to Mazda to make this the best-handling car in the midsize sedan segment.

Out on curvy back roads, body roll is nearly nonexistent, and understeer never rears its ugly head. Braking power remains strong and secure after a long day of hard driving. There's a Sport driving mode, but it doesn't even feel necessary -- I'm completely satisfied with the standard dynamics. Sport mode only changes the transmission's shift points, anyway, so it doesn't add much to the already brilliant default setup.

The turbo engine is said to return an EPA-estimated 26 miles per gallon combined, which bests the Kia Optima 2.0T, and matches the Chevy Malibu 2.0T and V6-powered Nissan Altima. (The 2019 Altima will use a new variable-compression turbo engine, so I'll be interested to see how that one stacks up.) During a week of testing, including a drive from Los Angeles to San Francisco, I saw 25.1 mpg on the trip computer.

I'd love for Mazda to offer the turbocharged engine with a manual transmission, but I know, I'm fighting a losing battle. If you do want some Mazda6 manual action, you can only get it on the base Sport trim with the naturally aspirated 2.5, which has 66 fewer horsepower and 125 fewer pound-feet.

Oh, and speaking of power, if you want the turbo Mazda6 to achieve its peak 250 horsepower, you'll need to run it on 93-octane fuel. If you fill your car with regular 87, Mazda says you'll be leaving 23 horsepower on the table.

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Luxury touches

Though the exterior styling is only a wee bit different than last year's model, the Mazda6 gets a helping of style and substance inside. Top trims get sleek suede seat inserts and natural wood trim pieces, but even without these niceties, the Mazda's interior is lovely. Quiet, too. Mazda says it added 70 new parts to improve overall levels of noise, vibration and harshness (NVH), and it really makes a difference.

The seats use a new design that are said to reduce fatigue on long journeys. The front chairs get a slightly angled seat bottom cushion with denser foam, which keeps your back straighter and butt cushier. After 6 straight hours behind the wheel, I feel no discomfort. Combined with the NVH tweaks, it all means the 2018 Mazda6 is a better place in which to spend time.

Improved tech

The Mazda Connect infotainment system is housed in an 8-inch touchscreen. However, the screen only operates by touch when the car is stopped and in Park. For controlling Connect on the go, you'll have to use the rotary knob on the center console.

Though the no-touching-while-driving rule is kind of ridiculous, I actually like using the rotary dial better. There's lots of tactile feedback and I appreciate the shortcut buttons placed around the dial itself.

I like the Mazda Connect system because it's so simple to use. Connecting my phone via Bluetooth is a quick process, and radio presets are easy to add. The onboard navigation system has a useful point-of-interest search function, though its graphics aren't as rich and crisp as other systems.

As for Apple CarPlay and Android Auto, they aren't available right now, but that'll soon change. Mazda says current 2018 model year owners can have this tech added at the dealership starting in July, and all cars will ship with Android and Apple connectivity beginning in December. Mazda is no doubt late to the game here, but I'm glad it's catching up.

Driving aids like blind-spot monitoring, lane-keeping assist and adaptive cruise control are standard across all trim levels, except for the base Sport, where they're bundled into a $625 package. You can set the lane-keeping assist to notify you of lane departure via an audible chime or a rumbling sound from the speakers, though if you want to be discreet, you can also select a steering wheel vibration option. Adaptive cruise control can bring the Mazda6 to a smooth, complete stop -- a godsend in heavy Bay Area traffic.

The top-end Signature trim comes with a head-up display with traffic sign recognition, as well as a 360-degree camera. The HUD is now projected onto the windshield, instead of Mazda's previous cheap-looking pop-up screen, which is great. Not so great, however, is the grainy resolution of the 360-degree camera. It looks as pixelated as a movie streaming in 3G on a first-gen iPhone.

How I'd spec it

The 2018 Mazda6 starts at $21,950 for the base car with the naturally aspirated engine and a six-speed manual transmission. On the other side of the spectrum, my fully loaded Signature model with the turbo powertrain comes in at $34,750.

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For my money, I'd probably take the Grand Touring trim, which starts at $29,200. It's the least-expensive way to get the more powerful engine and still comes with all the driver's aids I'd want. A definite extra is the gorgeous soul red paint -- it may be $750, but it's richer than anything you would've got from Earl Scheib.

A premium, sporty sedan

The Mazda6 isn't the only game in town, and it plays in a really competitive segment. The Toyota Camry is new this year, and better to drive than before. The Accord is also a fine choice -- one of the best cars in this class -- and comes with Honda's proven reputation for reliability. Hyundai offers a turbocharged Sonata, as well, though it's not quite as nice to drive as the aforementioned competitors.

For me, though, the Mazda6 is the pick of the litter. It's gorgeous, and feels truly premium inside. Plus, it's the best-handling, most fun-to-drive car in the class, hands down. Life's too short to drive a boring car.