In its long career, the SL has often embraced the noblest Mercedes engines. Four cylinders are therefore not really his tea. The first W121 generation, sold only from 1955 to 1963 and offered in the form of a roadster, already adopted such a “common” mechanical architecture. But today, under the long hood of the latest version, codenamed R132, a “quadruped” is back. The Mercedes-AMG SL 43 is indeed equipped with a small 2.0 l turbo. even if he didn’t choose any of them. He chose the M139, which has held the title of the world’s most powerful four-cylinder ever since it landed in the 421-horsepower Mercedes-AMG A 45 S.
An electric turbo like in Formula 1
To fit the 2+2 star roadster this engine had to be installed in a longitudinal position. It now uses only the rear wheels and is paired with a nine-speed MCT automatic transmission, in which the torque converter is replaced by a dry clutch instead of the dual-clutch 8G-DCT of the A-Class family. Less power and torque with “only” 381 hp and 480 Nm. But in return it achieves a mild 48 V hybridization with an alternator-starter that can deliver 14 hp more in certain situations and, above all, an innovative turbocharger. As in Formula 1, the latter contains a small electric motor, It is only 4 cm thick, which intervenes when the volume of the exhaust gases is not enough to drive the turbine fast enough. This will reduce the response time of the turbo to almost zero and provide better usability at low revs.
Performance drops, weight drops too
With its 585 hp biturbo V8, 800 Nm of torque and all-wheel drive, the only 63 4Matic+ version currently offered in France is surely off to a clear start in terms of performance. Top speed drops from 315 to 275 km/h in this SL 43 AMG, From 0 to 100 km/h, it goes from 3.6 to 4.9 s. But down to 1,810 kg instead of 1,970 kg, it can provide more agility even without opting for optional all-wheel steering. Mild hybridization and halving the number of cylinders reduce CO emissions while2nd significantly: with the V8 4.0 l showing 282 to 294 g/km, the range in this 2.0 l version is between 201 and 214 g/km.
A more reasonable price and penalty
The penalty will no longer reach the ceiling of 40,000 Euros, however, it will remain between €15,506 and €25,349. At the rate of 10 € per additional kilo above 1,800 kg, with no tax on the minimum weight of 100 €. Even if we have to stay away from the €190,750 claimed by the 63 4Matic+ variant, that sum must be added to an already promising selling price. With such deterrent taxation, it’s the future E Performance plug-in hybrid version that risks succeeding in France. However, we will have to wait a few more months to find out.