2023 Chevrolet Corvette C8 Z06 review – the American 911 GT3?
The C8-generation Corvette has drawn level with the European establishment for performance and finesse – can the Z06 go one better?
The Z06 isn’t hard to find in the multi-storey car park; it’s low, wide, festooned with wings, and looks like it’s been coloured in with a highlighter pen. I expect the searing hue to be called Acid Drop or Ballistic Banana but apparently Chevy calls it Accelerate Yellow. Hmmm. Turns out that most of the Corvette colour names are similarly lame: Rapid Blue, Red Mist, Silver Flare...Which is a shame because the rest of the Z06 is a riot.
It was a bold decision by Chevrolet to make the C8 Corvette mid-engined after seven generations and almost 70 years using the classic front-engine, rear-drive layout. It’s almost as if the bosses looked at the looming electrified future and thought, well, it’s now or never. Turns out that the real reason the C8 went mid-engined is the Z06, though the inevitable ZR1 version, with around 800bhp, will also benefit.
The entry-level C8 Stingray picked up multiple awards, most of them from American magazines it’s true, but in one way that makes them more valid, given how revered, finely developed and successful the C7 Corvette was. We too were impressed when we tested a right-hand-drive Stingray over here (evo 303) because while it has the heart of a traditional muscle car – a rumbling, 6.2-litre, pushrod V8 making 475bhp – in terms of dynamics, quality and general finesse it proved more European than any previous Corvette.
So the £82k Stingray aligns with the Porsche 911 Carrera and the Z06 squares up to the 911 GT3. And this is where it gets interesting: the Z06 is powered by a 5.5-litre V8 but it’s an all-new, naturally aspirated, flat-plane-crank V8 that revs to 8600rpm and delivers 670bhp. It’s called the LT6, or Gemini, and it’s the world’s most powerful naturally aspirated production V8.
If things had gone according to plan we’d have tested the Z06 in the UK on two gloriously sunny days, including one at Anglesey Circuit with our timing gear, but we were stymied by paperwork issues and so find ourselves near Frankfurt, Germany, on a chilly, grey morning. Our host, long-standing Corvette PR man Patrick Herrmann, hops into the Z06 and fires her up. Moments before, a previous-generation Corvette had sauntered by, its V8 burbling menacingly. When the Z06 starts up, my first thought is Ferrari 458, because its engine whoops into life with the light, four-cylinder note typical of a flat-plane V8.
The Z06 is a different beast to the Stingray in lots more ways. You get upsized brakes, bigger wheels and tyres and wider arches front and rear to cover them. You get adjustable magnetorheological dampers and springs that are 35 per cent stiffer, an aero pack delivering modest downforce at very high speeds, and a more comprehensive cooling system configured with track use in mind. All the radiators you can see – three in the nose, two in the yawning side scoops – are for water. The flow is front to rear, with some of the water diverted through those side radiators and then to the centrally mounted engine and transmission oil coolers.
Serious stuff, but this car has more. ‘Your colleague, James, requested the car with the Z07 upgrade pack,’ Herrmann tells us. For $8995 on top of the basic $105,300 starting price, this adds even stiffer springs (up another eight per cent) and more aggressive aero, including canards or dive planes on the front corners and the fixed, stepped carbon rear wing. They help double the downforce to 333kg at 186mph. You also get huge, Brembo carbon-ceramic brakes and massive Michelin Pilot Sport Cup 2 R tyres – 275/30 ZR20 front, 345/25 ZR21 rear – which look like cut slicks and prefer ambient temperatures a chunk higher than we are currently enjoying. Thanks, James.
This car is also equipped with the optional carbonfibre wheels made by Carbon Revolution, an Australian company. They replace the standard 10 x 20in and 13 x 21in forged aluminium wheels at a cost of $9999 ($11,999 in clearcoat) but you’ll save the best part of 5kg of unsprung mass per corner. This is such a significant amount that the power steering and ABS have to be recalibrated, and it’s claimed that fitting the wheels alone is worth 1 to 1.5 seconds per lap on mainstream racetracks... The wheels come with a heat-shield lining on the inside of the rim, but given that the bespoke Michelins are only said to give their best towards the end of a 12-lap stint, cool-down laps are apparently essential to avoid melting the spokes.
Out in the light, the Z06 looks long, wide and purposeful. A bit fussy too, particularly the nose with its jagged detailing of the splitter and the leading edge of the bonnet, but the car sits well, its front wheels tucked into the arches with a smidge of negative camber that will soon be physically evident as we manoeuvre on full lock and feel the tyres judder across the cold, damp asphalt.
Dropping in, there’s a lot going on in terms of cockpit sculpting, switchgear, screens and trim. While the mechanical hardware shouts race car, the equipment list whispers luxury car, the tally including electric memory seats, air conditioning, a 14-speaker Bose sound system, a HUD and heated and electrically adjusted wheel, but the spec will make a lot more sense after a couple of days and a few hundred miles. Switch on and a neat animation shows where the engine is. Push the start button and there’s no doubt. The sound is very 458 but with a slightly different quality to it; there’s a deeper note when the exhaust valves open up and generally a little less clarity.
The Z06 uses the same eight-speed, dual-clutch transmission as Stingray models, albeit with a shorter final drive to match the extended reach of the flat-plane LT6, while the electronic LSD is standard. The seats are well shaped and prove perfectly comfy and supportive after extended exposure, while the simple auto gear selector is a lovely bit of design, neat and intuitive. Next to it is a rather stiff, knurled rotary switch that changes drive modes, of which there are many. We’re currently in Tour, which could also be called Comfort. It’s a surprisingly easy-going set-up that delivers smooth and unobtrusive gearshifts and, despite the increase in spring rates, impressive ride quality. Yes, German roads are generally smoother than UK roads but we’ll find all sorts of surfaces and the Z06 will hardly put a foot wrong.
I have a few concerns around the steering, though. The first is that the wheel isn’t round, the second that its rim is part leather, part lacquered carbon, both of which seem wrong on a driver’s car. Of more concern, the steering is very direct at low speed, over-bright, the nose of the car jinking left and right with small inputs, and there’s not much feedback. I’m wondering how the Z06 will feel at speed, how this might combine with the as-yet-unknown grip/slip character of the Cup 2 Rs and an engine whose numbers suggest it does all of its best work high up the rev range, delivering peak power at 8400rpm and peak torque of 460lb ft at a lofty 6300rpm.
We’ve been ambling through semi-urban scenery so there hasn’t been a chance to extend the engine yet. By the time we find clear road, the V8’s temperatures are where they need to be. Showtime! I nail it from 2000rpm and one moment the 5.5-litre engine is hauling through the first 4000rpm with some conviction, the next moment the spark seems to hit the keg. The V8 finds its full voice, slams its shoulder behind the mass of the car and explodes with power, delivering an aural sweet spot between 5 and 6 before wailing to the 8500rpm red line. It’s stunning, like a huge, mega-punchy Honda VTEC. Chevy claims 0-60 in 2.6sec, the quarter mile in 10.6 and a top speed of over 200mph, reduced to about 195 with the higher drag Z07 aero kit.
It felt like there was only a little interjection from traction/ stability control, indicating that the lightly treaded rubber is generating some grip despite temperatures in the low teens, and that there’s decent mechanical grip. A quick blat on the autobahn shows that above 60mph the steering weights up and gains a strong self-centring action that makes the car positive in a straight line and damped off-centre too, imbuing a calm confidence. Wind and road noise aren’t intrusive, while long gearing settles the V8 to a refined cruise at 2000-3000rpm, its note melting into the background. There’s a resonance at around 4500rpm that cuts through like a buzz saw, though.
So far, so good for the LT6, though like all these flat-plane-crank V8s it can sound rather ordinary when it’s not in the zone, whereas a good cross-plane V8 delivers abundant and engaging character right across its operating range. Yet some US journalists seem entranced by the noise. One, KC Colwell, wrote in Car and Driver: ‘Flat-plane-crank V8s are a visceral thing. The intake sound reminds us of the sounds of our youth and draws in our adult selves like a siren song. The first time you hear a C8 Z06 start, your head will snap around like a kid getting called in to dinner on a warm summer night.’
Really? I guess it sounds rare and exotic if everything around you, from saloons to sports cars to outsize pickups and lumbering motorhomes rolls by with the heavy beat of a bent-crank V8. Here in the UK and Europe, where four-cylinder engines have long been the norm, a flat-plane V8 sounds, well, a bit flat. I remember feeling let down when Lotus built a V8 for the Esprit, a car crying out for a more exotic engine than the 2.2-litre slant four, only to find that while the brand-new V8 did the numbers, aurally the cylinder count was still four.
That said, thanks to Ferrari and McLaren, the sound signature of the flat-plane V8 has become something of a hallmark of junior European supercars, and there are solid engineering reasons to deploy it. The key advantage is that it pairs firing strokes on opposite cylinder banks and so requires minimal crankshaft balance weights, so it is faster to rev and is capable of higher revs (and therefore higher power) than a cross-plane V8. However, while primary balance is excellent, secondary balance is an issue and vibrations can play havoc with the reliability and durability of ancillary items. It’s an issue that can be mitigated to a degree by using lightweight materials for the reciprocating parts, and the LT6 does, employing titanium con rods and short-skirt aluminium pistons (which further improve response), but being so big at 5.5 litres amplifies the secondary balance issue.
Naturally, the Corvette development team benchmarked their rivals, paying particular attention to Ferrari. They bought a stock 458, then the opportunity arose to buy the 4.5-litre, 597bhp engine from a 458 Speciale, pinnacle of the Ferrari ‘F136’ V8s. It seemed a bit risky, sending $25k to Poland, but the engine duly arrived on a pallet at the Chevy engineering division in Pontiac, Michigan. It was worth every dollar, inspiring and informing development of the LT6, particularly in regard to isolating electrical components from vibrations.
A glimmer of sunshine, temperatures now in the heady mid-teens and some looping, sparsely trafficked roads are encouraging and the pace picks up. ‘Tour’ is still working admirably but there’s plenty more in the locker. Some of the drive modes, such as Wet, Tour and Sport, come with fixed parameters, the central screen showing you how various attributes are configured, while others such as Weather and My Mode allow you to adjust those attributes. And then there’s Z mode, engaged by a press of the steering wheel-mounted button, rather like BMW’s M modes. Z mode is inherently sporty and allows you to adjust steering weight, damper stiffness, drivetrain feistiness, traction control and even brake response.
The tyres would probably like another five degrees C but they’re delivering, and the Z06 chassis feels direct and positive, its steering accurate and well-weighted. The hammer goes down and the revs stay mostly above 5000rpm for a couple of miles. It’s thrilling and absorbing, a challenge to keep the engine in the manic zone and exploit the enormous grip, the Z06 scything through long sweeps and hanging on through the tighter stuff like a conker on a string. The front end is willing and grippy, but however aggressively it hooks into the apex, the rear never feels like it will get loose. Even with the engine delivering hard, the grip of the now-warmed-up Michelins keeps everything under control.
It’s intense, demanding all your attention. The carbon brakes that started the day feeling and sounding a bit grindy are tirelessly arresting the mass, though squealing like they’re fitted with racing pads. There is a degree of dynamic adjustability on and off the throttle to trim lines without disturbing the inherent poise of the mid-engined chassis, and when you finally find the limit, stability control prevents the rear breaking loose. Turn everything off, find a corner where the engine is into its power band at the apex and the Z06 demands quick hands but will oversteer as tidily as you’d hope a mid-engined car with a big-capacity, naturally aspirated engine would. Good job, Chevy.
It would be even more engaging, though, with a modicum of steering feel, so that you’d know when the front tyres were reaching their limit and, therefore, that the rears were too. Maybe there’s more feel on the Michelin Pilot Sport 4 Ss. Whipping the Corvette along at the pace it’s capable of reveals a few other things. Although it’s similar in concept to the Ferrari 458/488/F8, it doesn’t have their lightness of touch, their feeling of dynamic agility, which is partly down to set-up and partly because the Corvette is about 150kg heavier. It’s very long-geared, too; the first three ratios are closely stacked but from fourth they stretch out, with top speed attained in fifth or sixth, making seventh and eighth overdrives.
This brings us back to the contrast between the Z06’s race car-like mechanicals and its luxury equipment levels. Despite the aero, semi-slicks and race car engine, the Z06 has remarkable bandwidth, even with the Z07 pack. Select Track mode and the chassis becomes so taut, so positive and planted, you’d think it was a different car. Indeed, there are times when it feels like you’re driving a race car on the road, except few race cars have such absorbency. Then, in a moment you can be back in Tour mode, cruising along in comfort at 80mph, in eighth, with the engine barely audible, maybe with the carbon roof panel locked into its mounts in the rear boot.
In short, you could very easily daily a Z06 and have it as your trackday car. Like a 911 GT3, then, but with a better sound system and less austere interior. The only issue would be those Cup 2 Rs in the cold and wet. Oh, and a nose lift would be a boon.
The good news is the Z06 is coming to the UK in right-hand drive; expect it to cost £135-140k with the Z07 pack and carbon wheels. Great value, then, but is it as desirable as a GT3? Or as compelling as a Ferrari F8 Tributo or McLaren 720S? Well, it’s not as exotic and it’s certainly not as subtle. It is, however, very hard to ignore.