The SL 43 is also not short on power. Its M139 engine is a development of the one in the A45. At 375bhp, it has slightly less peak power, but is boosted in two ways by a 48V mild-hybrid system. There’s an integrated starter/generator that can contribute 13bhp but, more interestingly, an electric motor in the turbocharger can spin it up even when the flow of exhaust gas is still weak, thus improving throttle response.
Where the SL 43 might just have one over the V8s is that it’s the only SL that comes without front driveshafts. Add in a lighter front end and alloy wheels that are an inch smaller, and it might just be the keen driver’s choice.
Driving the SL 43 back to back with SL 55, I found I preferred the 43 in many ways. Straight out of the car park, the steering feels slightly slower (still only about two turns lock to lock) and slightly lighter, but that just serves to make it feel more natural, and once you get some speed up, it communicates really quite nicely.
The whole car feels lighter and more on its toes, diving in to bends more keenly and belying its 1735kg weight, even without four-wheel steering. Get on the power hard out of a tight corner and it’ll even rotate a bit. Those 295-section Michelin Pilot Sport 4Ss take quite a bit of unsticking, so it’s no Toyota GR86, but it helps to make the 43 more engaging than the 55. The taller sidewalls take a bit more edge off the ride too.