We had a real Canadian winter this year, with heaps of snow and frigid temperatures reminding us that although most of us don’t actually live in igloos, winter sure is part of our life here. I’m not a fan—I hate the cold, I don’t ski or do any other winter sports, and I’d rather hibernate by a fireplace until spring hits. But I’ll admit, it’s easy to warm up with a bright red 2025 Mercedes-AMG CLA 45 S sitting in the driveway.

The CLA 45 S is the baby of the Mercedes-AMG lineup, but on paper, it doesn’t scream AMG at you. They’re supposed to be big and brawny, with mobster road presence and more than enough power to spin the world on its axis. The CLA 45 S is almost none of those things; it’s diminutive, coming in shorter overall than a Hyundai Elantra and smaller inside than an Acura Integra. It has only four cylinders under the hood, half of what you’d expect from an AMG. It’s also all-wheel-drive; we’re used to all-wheel-drive AMGs, but not the front-biased AMGs like this CLA—more on that later. History asks for massive V8s and massive burnouts from AMGs, so how the heck does this baby AMG make me forget about winter and wake up my cold, dreary heart?

Inside the CLA 45 S: cozy and toasty

Its thick, Alcantara-wrapped steering wheel is a good start, being heated and all—as are the excellent, optional AMG performance seats, which are heated as well. But it’s more than that: the CLA 45 S shares a steering wheel with its bigger, more macho brothers, including the funky, screen-based controls to adjust drive settings on the fly. The interior feels proper modern Mercedes, too, with metallic air vents and all the dynamic ambient lighting you could possibly want. I’d even go as far as to say it feels better-built than some of their pricier offerings. You’ll find leather, Alcantara, and aluminum trim all over; the MBUX infotainment is as delightful to use as it always has been, and the Burmester sound system is punchy and clear.

I had no issues with front seat room, but the rear is cramped. The CLA has minimal legroom, and the sloping coupe-like roofline compromises headroom. I probably shouldn’t share this, but my wife may or may not have conked our toddler’s head on the roof pillar while securing him into his seat. He’s fine, I think. Trunk space isn’t that much better; at 328 litres, something like a Honda Civic offers significantly more.

What’s the CLA 45 S like to drive?

The CLA 45 S really cranks up the heat when you get moving. It isn’t your typical AMG recipe, but the outcome is no different, powered by a 2.0-litre turbocharged four-cylinder engine. Sure, it’s tiny for an AMG, but it’s literally the most powerful production four-cylinder engine on the planet. The turbo produces up to 30 psi of boost, allowing the four-pot to churn out 416 horsepower and 369 pound-feet of torque—hardly small numbers and befitting of the AMG badge.

All this power reaches all four wheels through an extremely responsive eight-speed dual-clutch automatic, and as mentioned before, a front-wheel-drive-based AWD system. I thought I’d take more of an issue with this, but the clever diffs helps the CLA 45 hide its FWD nature in most conditions. Despite the low ground clearance, this littlest AMG had no issues working its way through deep snow. In the dry, flooring it elicits a surprised “holy sh-t!” from both drivers and passengers. It rockets to 100 km/h from a standstill in 4.1 seconds, quickly and aggressively banging through each gear to the next one, whether you’re clicking the paddle shifters or letting the computers do the work. It’s downright shocking how quick this little monster is, and the power doesn’t drop off entirely at redline despite the very boosted nature of the engine. There can be a modicum of turbo lag, but it’s mostly imperceptible and the transmission is eager downshift in every drive mode—including comfort—to ensure you have the power you’re looking for.

Beyond the drivetrain, the CLA 45’s steering is accurate and well-weighted. It doesn’t have the immediacy of other AMGs with rear-wheel steering, and there’s a slight artificial feel, but it doesn’t take away from the experience. Like other AMGs, ride quality is on the harsher side regardless of the drive mode; I’d appreciate a much softer ride in comfort given the three-pointed stars everywhere. I found myself driving the CLA 45 S with everything dialed to Sport Plus, but keeping the dampers in comfort to ensure my fillings stay in place.

By now, you can understand why the CLA 45 S gets me going, and I haven’t even touched on the looks. The only exciting option on our tester was the Patagonia Red paint, which is a whopping $2,300 option. Outisde of that, not many option boxes were ticked: it didn’t have the optional forged wheels, the black-out Night Package, or the AMG Aerodynamics package, which adds more aggressive aero including a bigger front lip and bumper canards. I’d spec all of these on the CLA 45, because it looks rather tame in base form, despite the Panamericana grille and quad-tipped exhaust.

The verdict

What the CLA 45 S gets bang-on is the outcome of what you expect from the AMG formula. Forget the old formula and just think of the end result—it’s masterful.  The thrust is addictive, the grip is prodigious, the shifts are eventful, and the sound is maniacal. I really don’t care that much of it is piped in through the speakers; it creates so much drama that you can’t help but giggle. It sounds just good from the outside, too, so the fact that it isn’t totally fake is icing on the cake—a very good one that feels like it’s made by a skunkworks group at Mercedes-Benz, ignoring corporate rules and making something just for the fun of fit.

Mercedes-Benz could’ve stopped at the CLA35. It’s perfectly fine, quick enough, and costs less. On the other hand, the CLA 45 feels niche by comparison. How many people really want something very entertaining and still somewhat practical year-round, but small and coming in at $85,100 as-tested—roughly the same money as a BMW M2 or a Cadillac CT4-V Blackwing? The 2025 Mercedes-AMG CLA 45 S shouldn’t make sense, but I can’t argue with how it got me all hot and bothered in the middle of winter.