Two cars, 1,285 horsepower, 1,212 lb-ft of torque, and $309,455 worth of madness. This wasn’t deliberately designed to be a comparison test, but when the 2025 BMW M8 Gran Coupe Competition we spent a week testing had a starting price within a stone’s throw of the as-tested price for the 2025 Cadillac CT5-V Blackwing that arrived the following week, it was inevitable. It helped that both bear over 600 horsepower, blue paint, and luxury brand bones that make you want to hit the road and point to the horizon. Cars sure are good today, aren’t they? The golden era of super sedans is in full swing.
In One Corner: The German
While the car world fawns and frowns over BMW’s new M5— and rightfully so, since it’s the model’s first appearance in wagon form Stateside and simultaneously the model’s first-ever iteration as a hybrid– there’s a beast of prettier (and less complicated) appeal in the company’s catalog. It’s called the M8 Gran Coupe, and on paper the Competition spec tested here has the makings of the full package: Speed, style, and substance.
Under the hood is BMW’s 4.4-liter twin-turbocharged V8, in this guise good for 617 horsepower and 553 lb-ft of torque. It’s paired to an 8-speed automatic and all-wheel-drive, the result of which is a 0-60 MPH time that BMW quotes as 3.0 seconds flat. We all know BMW underrates its engines, so figure the actual sprint is handled in the high 2-second range. For a combustion-powered, four-door car that weighs a hefty 4480 pounds as per the manufacturer (even despite a carbon fiber roof, which does lower the center of gravity but doesn’t do much to help the two ton-plus mass), it’s spectacularly quick.
The M8’s interior is highlighted by the brand’s 12.3-inch infotainment center and is standard BMW fare in terms of design and layout. The Merino Midrand color palette is delightful and the seats are comfortable if not slightly more snug and firmer than we would think optimized for this application, though we suspect they soften up after some time. All in all, the M8 is a mighty fine place to spend time.
Pricing? Well, you better bring your checkbook. The M8 Competition Gran Coupe starts at $138,800. This test car– as test vehicles usually are– was optioned to the moon, skyrocketed by the Maritime Blue paint ($5,500), Merino Midrand leather ($3,500), Bowers & Wilkins Diamond Surround Sound audio ($3,400), M Driver’s Package ($2,500), and M Carbon Exterior Package ($5,400). Total MSRP with Gas Guzzler Tax and Destination: $171,575. Oof.
In the Other Corner: The American
The Blackwing represents the most powerful sedan General Motors has ever produced, and the car community (including yours truly) have deemed it one of the best performance sedans ever made. A CT5 at heart, the big brute is worked over by some exceptionally talented chassis and powertrain specialists to become what is technically the CT5-V Series Blackwing, commonly referred to by the Blackwing moniker. The American sedan touts a 6.2-liter supercharged V8 designated LT4 that makes 668 horsepower and 659 lb-ft of torque which is sent exclusively to the rear tires. A 10-speed automatic handles the job in the car seen and tested here, but the standard gearbox is a glorious six-speed manual. That’s right: 668 horsepower, six-speed stick, rear-wheel-drive. Anyone who buys one is doing the lord’s work and should familiarize themselves with GM’s excellent Performance Traction Management (PTM) system.
Step inside the Caddy and you’re greeted with a 33-inch screen that seemingly spans more than half the car’s width, and we do admit to liking it quite a lot. The digital gauge is somewhat cluttered yet works well and the center screen is well within reach and still has hard buttons for HVAC, volume, and screen controls. We prefer it over the BMW’s infotainment center even though they’re similar in concept; Cadillac’s is simply more intuitive, easier to navigate, not as needlessly complex, and equally fast on the software front.
There is a lot more hard plastic spattered about the Blackwing’s interior than can be found in the M8’s, which comes as no surprise given the cars on which they’re based: A base CT5 can be had for sub-$50k (a spec usually found in rental fleets at your local airport) while the 8 Series Gran Coupe’s cheapest offering is $90,800. Realistically, only buyers will decide if the ratio of soft touch points versus parts-bin plastics hampers the experience, and that decision is likely going to be made before they ever even touch the showroom floor of the vehicle challenging their predisposed bias.
The Cadillac’s base price would have you think it’s drastically cheaper than the BMW, and it is, but it’s still by no means chump change. The base price is $95,595 and the test car had option boxes ticked for Drift Metallic paint ($625), 19” Satin Graphite wheels ($600), Super Cruise 1 ($2,600), the 10-speed automatic transmission ($3,675), Carbon Fiber 1 package ($5,600), Natural Tan leather interior with “custom quilting” and carbon-fiber seatbacks ($8,090), and the Precision Package ($18,000) that is the highlight of the 2025 model year’s mild update. Total MSRP: $137,880.
As Daily Drivers and Grand Tourers
Both cars have trims below those seen here that would serve better in the daily driver category. But where’s the fun in that? With so much power on tap and a long wheelbase (3-plus inches longer than the Cadillac’s), the M8 is a mile-murdering machine. Devouring enormous highway stretches would be easy in this car; of the two here, it’s the one we’d choose for a road trip. The M8 is just a bit more supple and relaxed when you aren’t looking for Full Kill mode.
The downside to the M8’s sloping roofline is that it’s suboptimal for a daily driver into which the loading of young children is a regular occurrence. Doing so requires carefully navigating a toddler’s head when putting them into a car seat. It has us thinking the M5 that just went out of production would be a better pick as a whole. It’s not as stylish, but we don’t care.
Around town, the M8 unsurprisingly rides better of the two, with potholes and poor road surfaces transmitting to your spine less than in the Cadillac. We’d prefer a little more sidewall on the tire, as sharp and harsh edges are more pronounced than anyone would want from a BMW.
Left to its own devices, the M8 is a little more efficient and a little more docile than the Blackwing. The turbocharged engine means the M8 can relax in a way the Caddy can’t, allowing its engine to effectively sit below the boost threshold when at a leisurely highway pace. AWD, too, means that even in monsoon-like conditions you can accelerate from a stop on an uphill without second thought.
In similar conditions the Caddy can be wheelspin-happy unless the absolute most delicate application of the throttle is exercised. It’s hilarious fun, but it’s more work and requires maturity and restraint in a way the BMW doesn’t. That supercharged engine is also a little less prone to relaxing, its explosive supercharger always more immediate to respond than the M8’s turbos. Passing slower cars is easier, but fuel economy suffers accordingly (as is reflected in the Cadillac’s Gas Guzzler Tax coming in at $1,700 to the BMW’s $1,000).
As far as comfort goes, neither is the plushness winner of each vehicle’s respective lineup, but we wouldn’t hesitate to drive either cross-country. The BMW’s seats are a little softer and better day-in-and-day-out, yet they’re accordingly a little worse for hugging you in the corners. Practicality? Both cars have sizable trunks (we fit a 44” TV in the BMW’s without issue), both cars seat four comfortably (with a fifth in an absolute pinch), both cars make a statement wherever you go, and both cars work extremely well as daily drivers should your budget allow for the fuel they suck down.
When it comes to Dad Duty, it’s a toss-up as to which is better. The Blackwing allows easier ingress, yet the carbon-backed buckets don’t take too kindly to toddler feet (then again, does anything?). The M8 might be ever-so-slightly more roomy, though the roofline makes navigating a moving child’s car seat buckles a bit of a hunched-over affair, or at least more so than has to be done with the Caddy. And daycare dropoff cool factor? To us, nothing beats the sound of the Caddy starting up, even if the BMW might have more widespread curb appeal.
As Sports Sedans
Accidentally in each others’ cross-hairs, both companies have turned up the wick as high as the corporate overlords will let out the reins for the given models, and it’s a glorious thing to have vehicles like this on sale simultaneously, let alone at all. Drive them at even 5/10ths and it’s apparent the people who designed and engineered the M8 and Blackwing care deeply not only about the products they stand behind but about driving and the feelings it can create when behind the wheel of a properly sorted car. Chassis, motor, and handling all fall in harmony.
The most fundamental difference (aside from the obvious in country of origin and luxury-forward priorities) comes with the powertrain and driven wheels. Turbocharged and all-wheel-drive for the BMW versus supercharged and rear-wheel-drive for the Caddy; different means to a similar end. As expected, these play absolutely critical parts in each car’s playfulness and ease of extracting maximum (within our limits) performance, and in turn become components of each vehicle’s character that is perpetually on display.
From a standstill or roll below 30 MPH, BMW’s powerplant acts as a sizable bomb with a fuse only restrained by your right foot. Plant it and it effectively teleports the M8 to a point that was once much further away. If you want to scare passengers in double-digit speeds, you’ll have to buy an electric car to do any more of such than you can in the M8. Holy hell is it quick.
The BMW can carry exceptionally high speeds at all times thanks to the endless horsepower when the engine is in boost and the effective safety net that is the traction all-wheel-drive provides when conditions are less than favorable. If anything, the BMW’s weak point is when you turn the wheel. The steering weights up nicely in M modes, but feel and feedback is as dead as sensibility in BMW’s current styling department.
In the corners the M8’s grand touring roots shine through, for better and worse. With BMW’s Active M Differential and M xDrive on board, there’s no doubt the M8 Comp GC gets through the twisties with remarkable ease. We just don’t find doing so particularly fun or engaging; you feel as if the car is going through the motions and perpetually working out ways to do so with even more speed, rather than existing to serve your endorphins.
Of course, M xDrive’s party trick is its ability to run in 2WD– yes, RWD– mode. With a push and hold of the traction control button then a toggle through the M Mode screen to 2WD, it’s a different animal. The steering feels more precise too, and suddenly the car is privy to the not-very-BMW mischievous fun that is the pairing of rear-wheel-drive and big power. It’s good in concept at least; breathe on the accelerator pedal the wrong way below 40 MPH and the M8 lights up the rear tires. The resulting outcome is exciting and unsettling, but I wouldn’t go so far as to call it fun. Clearly not designed for this as a priority, the rear axle hops quite a bit and the turbo surge makes breaking traction somewhat unpredictable. It’s nice to know this car can be driven in RWD, and the mildly terrified laughs drown out the woes the steering feel’s lack of joy delivers, but that’s not how the car’s drivable limit is meant to be extracted.
Then there’s the Cadillac. The test car’s powder blue Drift Metallic paint betrays the monster within; make no doubt about it, the Blackwing is an absolute weapon. Power is more immediate with the supercharger than is the result of the M8’s turbochargers, and it feels like there is no delay whatsoever between your brain’s choosing ballistic thrust and the car employing such.
You know the Cadillac’s character from the second a cold start blasts your eardrums with its supercharged V8. It’s not as loud or obnoxious as the same engine is in the Escalade V, and yet it’s still quite a bit louder than the BMW. Firing them up, the M8 awakens; the Blackwing erupts. Don’t just take our word for it, have a listen:
Out on the road in the Blackwing, the immediacy with which a prod of the loud pedal turns into acceleration– or, in many cases, a feeble attempt at such rewarded solely with wheelspin– is simply remarkable. The 0-60 MPH time is supposedly around 3.4 seconds with the 10-speed automatic (making it 0.2-0.4 seconds faster than the manual depending on which outlet you trust) which we don’t doubt requires the delicacy of a surgeon and road conditions to match. You could win an Australian burnout contest with this car, bone stock.
This makes the Cadillac playful to the tip of your comfort level, an experience as rewarding as your talent allows. We don’t doubt buyers could get into the Blackwing and over time extract more out of the vehicle, but with this much power and RWD it’s best kept somewhat in check; the Blackwing can and will bite you even with traction and stability control left on.
The magic though is in the chassis. With this much gusto and such beautifully engineered underpinnings, the Blackwing is endlessly entertaining. Magnetic Ride Control is so good now that it barely gets mentioned any more, and though the suspension is bumpier at softest than is the M8’s it’s by no means punishing. Between the chassis, suspension, and the immediacy of the drivetrain, the Blackwing toes the line perfectly between comfortable and crazy.
For 2025, the Blackwing can be had with the brand’s new Precision Package, which costs $18,000 (!) and includes a larger front stabilizer bar, revised suspension bushings, increased spring rates, recalibrated subsystems (MagneRide dampers, steering, chassis controls and Electronic Limited Slip Differential), a redesigned front end with aero ground effects, carbon ceramic brakes (which are $9,000 when ticked as a standalone option), and new front steering knuckles and rear suspension toe links which GM says allow for more aggressive wheel alignment for track usage.
Is the Precision Pack worth the money? We’ll let you be the judge. For the buyer who will track the car, adding these components independently would likely net as much added cost as the pack itself costs, and when included here it comes with a warranty for added confidence. Our experience exclusively on public roads tells us the coin can be saved and put towards tires, fuel, and track days, but the Blackwing buyer might think differently; in fact, they might think that this is a future collector car and it should be loaded to the gills with every available item the catalog offers. And the crazy thing is they might be right.
Price and Value
It’s obvious that neither car here is inexpensive– not even remotely so. This isn’t just when it comes to the upfront purchase, but also when it comes to basic maintenance items like tires and brakes, and especially fueling. Cost of ownership more than likely isn’t something that prospective buyers of the M8 and Blackwing will consider, and yet we remember the days when the 2nd-generation CTS-V with its supercharged V8 just broke the $60,000 mark. In more cases than not, fun comes with a hefty price tag.
We touched on this before, but to revisit things: The BMW starts at $137k, roughly the same as the Caddy’s as-tested price, and as optioned is over $173k. That money also buys a nicely optioned Porsche Panamera GTS (base price $157k), an Audi RS6 Avant (base price $125k), or others. It’s a ton of money, even for a BMW. Skip the options and the M8 Comp poses a much better value.
Some of the same can be said for the Blackwing. The Caddy we tested carried almost $41k in options, a total which handily eclipses the M8’s $32,775 in additional equipment, for a total of $137,880. For daily driving and the occasional back road blast this car is perfectly good sans the Precision Package, and our test car’s interior additions and the Carbon Fiber 1 package also come in quite costly. Those who favor the six-speed stick over the ten-speed auto can save another $3,675. Meanwhile, skipping the driver-aid Super Cruise package pulls another $2,600 off the price. At the car’s $95,595 base price, and even when kept under the magical $100k mark, this is the super sedan value of the moment.
Everybody Wins
Drive the Cadillac and it’s very clear this is an all-time top choice for a super sedan, period. Since its debut for the 2022 model year, the CT5-V Blackwing has been the class leader; today, that’s no different. If you want a car that comfortably seats four (operative word being comfortably) and is thoroughly enjoyable to drive whether doing daycare dropoff or tackling the track, the big Blackwing is as good as it gets. Between it and the BMW, the Caddy is the one we’d permanently park in our driveway, and a car we’d choose over almost every other out there given the budget and lifestyle needs.
That’s not to say the M8 Competition is bad; it’s anything but. The BMW simply brings a different set of skills to the table and as such will appeal to a different audience. It shines and simultaneously slips beneath the surface of desirability as far as cars in this segment go, and yet we’d still have it over that new M5. The prior one? That car is an all-timer, too.
And so this “Comparison Test” draws to a close. Declare a winner? We’ll leave that to the media outlets that have to do so in order to preserve their perceived merit. What we have here are two cars that both make great cases for themselves and ultimately one that we daydream about longingly. When the V8s are gone altogether and sedans have been fully replaced by CUVs, the CT5-V Blackwing will always and forever hold a special place in our hearts.
