2023 Mercedes-AMG SL 43 First Drive Review: It lost four cylinders. No problem!

2023 Mercedes-AMG SL 43 First Drive Review: It lost four cylinders. No problem!

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HELL, Mich. – The 2023 Mercedes-AMG SL 43 is the high-dollar luxury convertible equivalent to the Mustang turbo vs. V8 debate. In other words, don’t rule out this four-cylinder Benz just because it has half as many cylinders as its 55 and 63 siblings.

We’ve driven those, and while largely impressed with what those convertibles have to offer, they sure aren’t picture-perfect. Enter the 43 with its longitudinally-mounted 2.0-liter turbocharged (to-the-moon) four-cylinder engine. What makes the 43 desirable is less about what’s in it, though, and more about what isn’t – approximately 350 pounds of curb weight. That includes all that’s removed by having two fewer driven wheels – the V8-powered SLs are all-wheel-drive-only, whereas the 43 exclusively has rear-wheel drive. It also lacks the impossibly complicated active anti-roll stabilization system from the 63, instead sticking to just passive-everything as standard equipment.


The list goes on, but the vital point here is that a boatload of weight and complexity is removed from the equation, leaving you with a more straightforward driving experience.

All that said, there is nothing more complex than the technology AMG baked into the little engine up front. In an effort to ward off what we typically refer to as “turbo lag,” the engineers used an electric exhaust gas turbocharger. In layman’s terms, that means there’s a tiny, 1.6-inch electric motor integrated on the turbocharger shaft that gets the turbo spinning before the exhaust gases join the party and keep it spinning the old-fashioned way. The goal is to make throttle response immediate from idle or while driving after you’ve removed your foot from the throttle. That electric motor, operated via the 48-volt onboard electrical system – can take over at a second’s notice and maintain boost pressure at all times so you never have to spin it back up. It’s an idea derived from MercedesF1 engine tech, and now you can buy it in a new car today. Neat!

Output for this hand-built AMG engine is a stout 375 horsepower and 354 pound-feet of torque. That’s impressive, but we can’t help wondering whether a halo car like the SL should have something less than the CLA 45 S coming to the U.S. that makes 416 hp and 369 lb-ft. Perhaps that number is just a little too close to the SL 55’s 469 ponies for Mercedes' comfort. Nevertheless, the SL 43 is claimed to run to 60 mph in just 4.8 seconds using launch control and top out at an electronically limited 170 mph. That’s 1.0 second slower than the 55 and 1.3 seconds behind the 63, but absolutely not slow and certainly not bad for dropping half an engine.

In a big plus for engagement, Mercedes sticks with its nine-speed multi-clutch transmission for shifting duties, giving you all the snappy rawness of the transmission fitted to its V8 models. It’s the perfect pairing for this four-cylinder engine, because short ratios and quick paddle response are your friends when power is in short reserve. Not to say there’s a lack of power, because the SL 43 will still briefly light up the rear tires when you spring away from a stoplight. Just make sure you tap it into traction control sport mode before doing so, because the ESC system hates fun with everything switched on.

The four-cylinder-ness really dominates the driving experience at all levels, even from the moment you switch the car on. Its idle is rough and loud, almost as if it’s missing balance shafts on purpose to convince you the engine is meaner and bigger than it is. Leave the exhaust in its quiet mode, and it makes very little noise at all when you’re cruising or under light acceleration. That constant thrum of the 4.0-liter twin-turbo V8 is missed here, as it makes the SL ooze with a more aggressive character. Get the revs up in the 43, though, and you’ll quickly learn that this engine has its own sweet tune to play. The buzziness at low speeds drops away, and a sweet, higher-pitched note comes on in the upper rev ranges, encouraging the driver to keep pulling the next paddle and play it again. It’s both racy and quick to charm. Mercedes found the right sound with this engine, because even though it may be the same size and have the same number of cylinders as hot hatches aplenty, it sounds like a sports car at full chat.