2023 Chevrolet Corvette Z06 vs. Porsche Cayman GT4 RS: Comparison Test Review

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Many Chevrolet Corvettes have faced off against Porsche 911s on the pages—web and actual—of car publications for decades, MotorTrend included. We might even be among the most frequent perpetrators of a somewhat odd battle: The two sports cars' polar-opposite engine layouts provided an appropriately overwrought metaphor for their obviously disparate upbringings. It was always the cheap 'n' rowdy Corvette with a big, dumb pushrod V-8 in its nose taking on the pricey Porsche. The latter has always been a car that, when compared to the Corvette, was born with at least enough of a silver spoon up its ass so a maximum of six cylinders could lay down and fit back there. Back and forth the comparison tests went.

Consider the mold broken. The 2023 Chevrolet Corvette has gone all exotic on us, its engine moving to the middle to break through the breed's front-engine performance ceiling. In track-ready Corvette Z06 form, it even ditches pushrods. A new dual-overhead-cam 5.5-liter V-8 with a flat-plane crankshaft scooches the new Corvette Z06 into a more deserving place in the global sports car conversation, delivering Ferrari noises and the most power ever from a naturally aspirated V-8 production engine. The 2023 Chevrolet Z06, festooned with carbon-fiber bits, including an optional set of lightweight wheels with more air space between their spokes than any previous offering, is the maximal eighth-generation (so far) version, an uncompromising supercar. So which 911 would you line it up against?

It's a trick question. Sure, the MotorTrend 2022 Performance Vehicle of the Year-winning 911 GT3 makes some sense, but it's down big time on power while costing more than the Z06. No, on this occasion of the Corvette's divine re-engine-ing, we're breaking the mold—by molding this comparison test for some fairness. It means finding a Porsche that's enough like the Z06. It means something mid-engine and track-focused—something like the Porsche 718 Cayman GT4 RS.

Yes indeed, for the first time there is a production Corvette with its engine in the same place as a similar production Porsche. It isn't a 911, but the Cayman GT4 RS has some 911 magic deep in its loins: a version of the 911 GT3's racing-derived 4.0-liter flat-six engine. Meanwhile, the Corvette Z06's new DOHC V-8 was designed alongside the racing version that propels Corvette Racing's C8.Rs around endurance racing tracks the world over.

Never mind that the Cayman has only six cylinders behind its seats—so does a 911. The GT4 RS' engine is, like the GT3's 502-hp boxer, down on power compared to the Z06's V-8. But even with "only" 493 hp, it's bolted to the smaller 718 chassis, maximizing its potential. The list of similarities between these two hardcore sports cars goes on: They both have dual-clutch automatic transmissions, notable aerodynamic upgrades, and exotic wheel materials (carbon-fiber for the Chevy, magnesium for the Porsche).

If a single aspect of the old Corvette-vs.-Porsche dynamic holds, it's in the area you'd guess: price. The standard Cayman may be the "starter" Porsche sports car, but in GT4 RS guise, it starts at $151,850—tens of thousands more than the $132,540 Z06 and nearly as much as a base GT3. With both test cars optioned handsomely with most available add-ons (and the 'Vette's Z07 specification), more than $30,000 separates them, the Porsche approaching new-condo territory at $195,100 all in. Porsche's prices have crept up, by the way, meaning this same RS now starts at $163,650. With the same $13,250 Weissach package and $15,640 magnesium wheels, plus the $8,000 carbon-ceramic brake package, $2,160 leather interior, $3,040 front axle lift, and various special-order baubles, $200,000 is on the table.

What with the 2023 Chevrolet Corvette Z06 winning our 2023 Performance Vehicle of the Year award—an award the 718 Cayman GT4 RS competed for—and with the price disparity, obviously the Porsche loses this comparison test, then? We can't deem it "obvious." As ever, the Porsche more than justifies its price; study the test numbers for a clue as to why. The Cayman GT4 RS very nearly keeps up with the vastly more powerful Corvette Z06 to 60 mph, around our figure-eight course, on the skidpad, during emergency braking, and more. One digit separates the Porsche from the Corvette in nearly all of those objective metrics—the GT4 RS is 0.1 second behind the Z06 to 60 mph; takes 1 additional foot to stop from 60 mph; and it delivers a negligible 0.01 fewer g of lateral acceleration.

Yes, that means this Porsche Cayman GT4 RS rips to 60 mph in 2.9 seconds, stops from 60 mph in 96 feet, and hangs on for 1.15 g's around our skidpad. Those are supercar numbers—and not far behind the 911 GT3's. Whether you think they're sufficient to justify the supercar label for a massively hopped-up version of Porsche's base sports car, well, that's between you and your ego and what you think "supercar" means.

Sporting nearly 200 hp less than the Corvette, the 718 Cayman GT4 RS shows what effect mass has on performance. By weighing some 450 pounds less, its power-to-weight ratio approaches the Corvette's, with the gap between their figures far narrower than the two cars' horsepower differential. Just as important is how the mass affects each car's feel. The GT4 RS simply moves more lightly on its tires than does the Z06, which feels massive by comparison. Both cars spasm into corners with even minor steering wheel inputs, but you feel the Z06 turn in. The Porsche? You think, you turn; the shorter-wheelbase chassis pivots on its axis without delay.

The Chevrolet is larger and feels like it, though none of our judges complained about its ability to change direction. Nor does size really seem to hold back the Corvette Z06's total performance. Despite just eking past the Cayman GT4 RS to 60 mph, around our skidpad, and stopping just 1 ft shorter from 60 mph, the Corvette lumbers away from it around our figure-eight course: The Chevy opens up a 0.4-second lead on the Porsche all while generating 0.05 more g's on average (0.99 to 0.94). In fact, the Z06's figure-eight time was so good, it briefly held MotorTrend's record time—until it was beaten that same day by a half-million-dollar McLaren 765LT Spider.

High speeds are where the Corvette thrives. While our objective acceleration data is mighty similar between the two, that's only up to 60 mph. Beyond that speed—and on through the quarter mile—the big-engine Corvette Z06 simply outpaces the Porsche, expanding its lead through 100 mph, which it reaches 0.7 second sooner.

Generating reassuring brake-pedal feel is one thing the 2023 Chevrolet Corvette Z06 could do better. Chevy allows owners to select (via the touchscreen's setup menu) one of two brake settings: The more aggressive one delivers the kind of ultra-firm, pressure-sensitive pedal you expect from a track car. It was the least objectionable but still felt artificial underfoot, even while delivering heroic and consistent braking performance. The more stroke-modulated setting was more vague in its responses, and the pedal felt overboosted. We had no such complaints in the Porsche, whose brake pedal feels like an extension of your leg. A few drivers complained of some front-end skipping on bumpier track surfaces, though, as if the front axle were bouncing along during hard braking.

If the Porsche could do something better, it's, well, everything off-track. Yes, both of these cars are designed to devour racetracks, but the Corvette is more satisfying off of one. The Cayman GT4 RS is more one-dimensional, what with its fixed-back seats, stiff ride, and cabin noise levels that rival the inside of a jet engine. Our judges were torn on whether the Porsche's ear-splitting intake noise was one of the greatest automotive sounds and features of all time, or akin to driving with a newborn baby set to "agitate" stuffed somewhere behind the seat.

You see, Porsche artfully routes the 718 Cayman GT4 RS' intakes through the quarter windows behind each seat, plumbing them first into the cabin and then down into the flat-six's intake plenum. That means occupants share acoustic space with the intakes, and those intakes are tuned such that the sound they generate changes pitch violently near the GT4 RS' 9,000-rpm redline. Imagine the old Lexus IS F V-8's "who-stepped-on-a-goose?" intake honking, only the goose is being tortured while being crushed. It's cool the first few times you access this crescendo, and headache-inducing for some every time afterward. Even wearing a full-face racing helmet, hearing protection was almost necessary to prevent our ears from ringing after a lapping session. Seriously, no one wants to avoid redline in their high-performance sports car—but the Cayman forces this kind of Sophie's choice every time you press the accelerator. Of course, next time we'll remember to add earplugs to our equipment bag, which certainly solves the problem.

When not suffering/enjoying aural assaults, the Porsche's occupants can enjoy the spartan, race-inspired environs of a stripped-down Cayman cabin featuring fabric door-pull straps. Our test car's optional fixed buckets only slide fore and aft, though the driver's seat features a hidden power height adjustment we found after a week of driving around Los Angeles. Either way, it's all pretty basic.

The Corvette feels like an Escalade by comparison. You can go full ham sandwich on a track before loafing home with your ventilated, multi-way-power-adjustable seat cranked to "chilly." The Z06's head-up display puts pertinent info up in your field of view, as useful when cruising a highway as when timing your perfect paddle-fired upshift on the track. And the Chevy's electronically adjustable suspension offers more range than the Porsche's, with the Tour mode returning a genuinely comfortable ride. With our Z06's Michelin Pilot Sport Cup 2Rs, there was some tramlining on conventional roads, but overall, this is a supercar that is nearly boring to drive when driven normally. OK, our Z06 test car came loaded, but we'd still pick a base model to drive a long distance, given the roomier cabin and more tame ride.

We mean it when we say these two mid-engine sports cars—supercars, even—are evenly matched, even if their on-paper specs suggest a yawning chasm between them. The Chevrolet Corvette Z06 wins this matchup at the margins, though. It's cheaper. It's a hair quicker, grippier, and stoppier. It also makes compelling vroom-vroom noises of its own. It's as good or better than the Porsche on track, and in a different class altogether in real life on everyday city streets and highways. The only natural thing to do, of course, is to line up the Z06 with its old sparring partner, the 911, and see what comes of it. But for now, the Corvette's big leap forward has dropped it into contention with the "lesser" 718 Cayman—and we couldn't care less, so long as we get more of this type of excellence as the Corvette story continues.

Verdict: The ultimate mid-engine Porsche you can buy today—but not the overall ultimate mid-engine sports car.

Verdict: Costs less than the Porsche, more car.