The GTS models are the most expensive versions of Porsche's new 718 Boxster and Cayman. Yet the automaker calls them a "value proposition for the performance enthusiast." Contradictory as that may sound, I promise, the proof is in the pudding.

Both 718s use the same 2.5-liter turbocharged flat-four engine as their Boxster S and Cayman S siblings. But thanks to a new intake manifold that improves airflow, as well as a larger-diameter compressor wheel for the turbocharger, overall output increases to 365 horsepower and 317 pound-feet of torque. That's with the seven-speed PDK dual-clutch transmission on board; if you spec the slick-shifting six-speed manual, torque is reduced to a still-healthy 309 pound-feet.

In the case of my Boxster GTS test car, equipped with PDK, the reworked engine produces 15 more horsepower and 8 more pound-feet than it does in an equivalent Boxster S. And though the GTS is 44 pounds heavier than its S counterpart, the increased output means it can hit 60 miles per hour 0.3 seconds quicker -- 3.9 in the GTS, compared to 4.2 in the S.

You might notice those three-tenths if you're racing other Boxster owners at your local drag strip, but out here on the vineyard-lined roads of California wine country, it's the GTS' other enhancements that really shine. Every 718 GTS comes standard with Porsche's excellent Active Suspension Management (PASM) chassis, which lowers the ride height by 10 millimeters, and 20-inch Carrera S wheels wrapped in sticky 235/35 front and 265/35 rear Michelin Pilot Sport 4S tires. Porsche also throws its torque-vectoring system into the mix, as well as larger brakes -- those 13-inch front stoppers are ripped right from the 911 Carrera.

Porsche will fit your 718 GTS with the stiffer PASM Sport suspension for a mere $290 (which reduces ride height by another 10 mm), or you can add carbon ceramic brakes for a not-so-mere $7,410. If you're planning to track your 718 GTS on the regular, these are upgrades worth considering. But for the sort of back-road blasting I'm enjoying on a sunny NorCal afternoon, there's absolutely nothing wrong with the standard GTS setup.

Go on, take your top off -- even if the Boxster GTS does cost $2,100 more than an equivalent Cayman.

Marc Urbano/Porsche

That includes the way it sounds, by the way. The flat-four's aural quality is a huge point of contention within Porsche circles, even though the new engine is both more powerful and more efficient than the flat-six it replaces. Honestly, I rather like the hearty, robust growl from out back, especially accompanied by the snaps and pops of the GTS' standard sport exhaust. The 2.5 doesn't sound bad, you guys. It's just different.

While we can agree to disagree on that last point, there's no arguing that, dynamically, this is a brilliant sports car. The steering is as beautifully weighted as it is precise in action, the GT Spirit wheel providing crystal-clear descriptions of at-the-pavement grip. With each new turn, I'm braking later, turning harder, getting back into the power sooner. The 718's inherent mid-engine balance is complemented by the GTS' torque-vectoring control to provide a level of mid-corner poise that feels totally unbreakable.

Honestly, the GTS almost feels too perfect. Where the 911 Carrera T allows for tiny bits of playful slip on these same gorgeous roads, the Boxster carves a line through each turn like a scalpel. But that also means it inspires a ton of confidence behind the wheel. Enthusiasts of varying skill levels could drive the Boxster GTS and feel encouraged to give it more, more, more. The harder you push, the greater the reward.

GTS models come with the 13-inch front brakes from the base 911, housed behind dark-finish, 20-inch Carrera S wheels.

Marc Urbano/Porsche

Given the fact that they're mechanically identical, you won't experience any loss of on-road loveliness should you opt for the hardtop Cayman GTS. But on a sunny May afternoon, it's hard to resist the topless temptation of the Boxster, even if it does cost $2,100 more.

Aside from its lack of roof, the Boxster looks no different than the Cayman from inside. The GTS models come with Porsche's Sport Seats Plus, and while these chairs offer comfort and support in spades, the fact that an $80,000-plus luxury car doesn't come with full power seats is kind of laughable. Yes, 14- and 18-way power seats are available, but they cost $2,330 and $3,030, respectively. Oh, Porsche...

That aside, the 718's interior is nicely appointed and wonderful to use over long periods of time. All pertinent driving information is clearly displayed on Porsche's usual tachometer-in-the-center gauge cluster, and all vehicle controls are neatly organized and easy to find while driving.

Soft Alcantara trim comes standard. Full-power seats do not.

Marc Urbano/Porsche

The Porsche Communication Management infotainment system is similarly likable. And while it isn't housed in the large, 12.3-inch display found in the Panamera and new Cayenne, the touchscreen interface is super responsive with an intuitive, easy-to-navigate menu layout. Apple CarPlay is standard, but like all Porsche models, Android Auto is still absent.

Even so, that's a small complaint in the grand scheme of this otherwise flawless package. Make no mistake, at $82,800 to start, the 718 Boxster GTS certainly isn't what I'd call cheap. Yet if you spec'd all of the model-specific go-fast bits to a 718 Boxster S, you'd actually be spending more money -- and you still wouldn't get the GTS' increased power ratings. If it's the best-performing 718 you seek, it'd be foolish to overlook a value like that.

The GTS might be the most expensive Boxster, but it's also the best performance buy.

Marc Urbano/Porsche

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