America’s love affair with SUVs has sprouted ever more new models in every shape and size, and more than a few ultra-powerful performance models. Yet, the Venn Diagram of the SUV realm’s myriad size classes and its horsepower-crazed offerings isn’t exactly an eclipse—particularly left out? Small SUVs, which generally are tepid and weak. Not the all-new 2021 Mercedes-AMG GLA 45, which builds on the original GLA 45‘s micro-niche offering of insane power in a tiny, semi-tall package based on the more pedestrian GLA 250 also redesigned this year.
AMG previously squeezed logic-defying power from its smallest engine, the turbocharged 2.0-liter used in the first-generation GLA 45 and its swoopy sedan sibling, the CLA 45. Things get less logical this time around, with the new subcompact GLA 45’s four-banger pumping out a decidedly un-subcompact 382 horsepower (at 6,500 rpm) and 354 lb-ft of torque (between 4,750 and 5,000 rpm). Those figures are up 7 ponies and 4 lb-ft over the previous-generation GLA 45’s already insane outputs. Consider that now, the GLA 45’s four-cylinder output is snarling just behind the 405 ponies pumped out by the BMW M2 Competition coupe‘s turbocharged six-cylinder.
To reach its lofty power output, the AMG’s hand-built 2.0-liter M139 engine features two-stage fuel injection, a redesigned intake system, and a new twin-scroll turbocharger for better throttle response. The result, AMG claims, is responsiveness similar to a naturally aspirated engine to go along with those big-time power figures that overwhelm anything else in the GLA’s size class. Among the next-most-powerful tiny luxury crossovers you can buy? The BMW X2 M35i, which offers “just” 302 horsepower from its turbocharged four-pot. Know what else makes 302 horsepower? The Mercedes-AMG GLA 35, the starter AMG that slots between the bonkers GLA 45 and the regular-grade, 221-hp GLA 250.
Mercedes further sets the GLA 45 apart from its lesser GLA 35 sibling by flipping the engine 180 degrees. Still transversely mounted, the engine simply faces the other direction than in the 35. The orientation situates the four-cylinder’s intake facing forward, toward the front of the car, while the exhaust and turbocharger components are located on the firewall side of the engine, a boon for cooling pathways, shorter-distance ducting, and “the flattest possible and most aerodynamically advantageous” front-end bodywork. OK, Mercedes.
Another 45-versus-35 differentiator? The former’s AMG Performance 4Matic+ all-wheel drive, which can not only split engine torque between the front and rear axles, but also side-to-side between the rear wheels to maximize traction. (The 35’s simpler setup lacks the rear-axle torque vectoring function.) Between the 4Matic+ system and the mighty four-cylinder sits a new eight-speed dual-clutch automatic transmission in place of the previous GLA 45’s seven-speed unit.
The AMG-fettled powertrain helps the GLA 45 scamper to 60 mph in 4.3 seconds, according to Mercedes—a figure we think is likely conservative. After all, even before the original 355-hp GLA 45 received a 20-hp injection for 2016, one year after going on sale, it matched that 4.3-second acceleration time in our testing. Mercedes-AMG once again says the GLA 45 is capable of—and electronically governed to—155 mph. While the 35 matches the 45’s top speed, it supposedly takes an extra 0.7 second to reach 60 mph.
Among the GLA 45’s host of driver-selectable driving modes are Slippery, Comfort, Sport, Sport+, Individual, and Race. There also is one mode named “Master,” which AMG says is exclusive to 45’s optioned with the available AMG Dynamic Plus package and should be used only on racetracks because it allows extra oversteer beyond “Race.” We’ll have to wait until we drive the GLA 45 and experience it for ourselves, but AMG notes that every drive mode alters the GLA’s stability control, all-wheel-drive system, transmission behavior, suspension softness, exhaust sound, and throttle response.
Handling improvements are promised thanks to the new GLA’s stiffer body shell, which provides a more robust basis for the suspension to do its work, and a new variable-rate steering rack. Torque steer, an obvious concern for so powerful a front-drive-based vehicle as the GLA 45, is said to be mitigated by AMG’s tuning of the MacPherson struts up front and four-link rear suspension setup, as well as the new-for-2021 electronic adaptive dampers. The 45’s front brake rotors measure 13.8 inches and are squeezed by fixed four-piston fixed calipers, while the rears are 13.0 inches in diameter and grasped by single-piston floating calipers.
Taken together, the Mercedes-AMG GLA 45’s advances for 2021 indicate that the most powerful small luxury crossover available extant remains so while surely being even more of a hoot to drive. Does the world need as many different types of SUVs as are available today? Who knows, but we won’t argue against more more powerful SUVs no matter their size. Speaking of size, while we know how (not) big the GLA 45 is, we don’t yet know how big its price tag will be. The old GLA 45 started at about fifty grand and only went up from there, and we don’t expect the new one’s bigger power to come with a smaller price tag when it arrives in the U.S. later this year.