2021 Porsche 718 Boxster GTS 4.0 Sings a Flat-Six Tribute

"So, you want a six-cylinder," Porsche seems to be asking rhetorically as it reinstates a screaming, naturally aspirated flat-six into the 718 Boxster and Cayman lineups after switching exclusively to turbo-four power starting for 2017. "How about the most powerful, highest revving one ever?"

It started with the 414-hp, 8200-rpm 4.0-liter flat-six in the top-dog Cayman GT4 and Spyder. The 2021 GTS 4.0 models that will arrive at the end of 2020 get a nominally detuned version that makes 394 horsepower and revs to 7800 rpm. But the difference is corporate pecking-order stuff: This Boxster, a German-spec 2020 model, shot to 60 mph in 3.8 seconds and through the quarter-mile in 12.0 seconds flat at 118 mph. That's no slower than the Spyder we tested, and just a tenth slower than the GT4. In fact, a second GT4, which recently beat the Corvette in a head-to-head comparison, went a tenth slower. Pro tip: You can't feel any difference in thrust between the two.

What's even better is that this engine—a bored and stroked version of the 3.0-liter that powers the 911, minus the twin turbos— is everything we love about Porsche's flat sixes: a responsive climb to towering revs, culminating in a strident, full-bodied roar that's a great balance of intake and exhaust noises. All GTS models have a two-mode sport exhaust with a button on the center console to make it louder. And it needs it. It's playing in the key of GT3 but more muted. Anyone who's basked in the glorious violence emitted by a GT3 or GT3 RS will want more than the 91 decibels we recorded in the GTS 4.0 at full throttle.

Being 2020, the engine automatically switches off when the Boxster comes to a stop, and it shuts down half its cylinders under light loads. The latter feature is heard when the exhaust note goes slightly flatulent, and there's a small driveline bump as it engages and disengages. However, both are disabled in Sport or Sport Plus modes or by hitting the auto-stop off button.

The six-speed manual transmission is more hand-me-down greatness. It's shared with Porsche's GT cars, and its shift efforts are excellent, as is the snap-in feel as the lever gets sucked into the next gear. If there's a downside, it's that the tall gearing means you don't get to experience shifting it frequently enough. The top of second reaches past 80 mph and most of the speed limits in this country. Attacking a 30-mph corner calls for a downshift into first. Yet, sixth gear is fairly short, with 80 mph equating to 3200 rpm and not great highway fuel economy. We averaged 23 mpg in our 75-mph fuel-economy test, which syncs with GTS 4.0's EPA highway estimate but is 2 mpg worse than the previous four-cylinder GTS.

Everything else that we love about the 10Best-winning Boxster remains. It is supremely balanced with massive cornering capabilities (1.04 g of grip) and wonderfully tactile steering. Brake-pedal response is phenomenal, as is the Boxster's capability to stop from 70 mph in just 141 feet and from 100 mph in 293 feet.

We've already called the GT4 the best car of 2020, and the GTS 4.0 delivers nearly all of that goodness at a starting point nearly $10,000 cheaper. Praise be!