How many kilometres can an all-electric CLA cover in 24 hours, including charging stops and driver changes? That was the question faced by the development team working to optimise the efficiency of the new all-electric compact class models. The impressive answer was provided by “Project N”, the internal code name for a project that is as secret as it is ambitious. N for Nardò: two close-to-production prototypes of the CLA set off on this high-speed route in southern Italy at the beginning of April 2024.
A CLA covered exactly 3,717 kilometres within 24 hours – and got further than other near-production electric vehicles The distance of the endurance run is equivalent to a trip from Trondheim (Norway) to Istanbul (Turkey). Air temperatures ranged from 13 °C at night to 29 °C during the day. The tarmac was even hotter.
The vehicle's battery was charged exactly 40 times at a standard charging station during the 24-hour test. The charging breaks only lasted around 10 minutes each time. If these are taken into account, the average speed was a remarkable 154.9 km/h. In the run-up to the drive, the experts at Mercedes determined the ideal charging strategy to maximise the average speed. On a real long-distance journey, this optimisation takes place via navigation with Electric Intelligence.
A CLA covered exactly 3,717 kilometres within 24 hours – and got further than other near-production electric vehicles The distance of the endurance run is equivalent to a trip from Trondheim (Norway) to Istanbul (Turkey). Air temperatures ranged from 13 °C at night to 29 °C during the day. The tarmac was even hotter.
The vehicle's battery was charged exactly 40 times at a standard charging station during the 24-hour test. The charging breaks only lasted around 10 minutes each time. If these are taken into account, the average speed was a remarkable 154.9 km/h. In the run-up to the drive, the experts at Mercedes determined the ideal charging strategy to maximise the average speed. On a real long-distance journey, this optimisation takes place via navigation with Electric Intelligence.
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MotorTranscript
00:00The efficient hybrid drive with 48-volt technology is a new development from Mercedes-Benz.
00:15The highlights of the new powertrain for compact vehicles are the new four-cylinder combustion
00:20engine M252, the electro-hydraulically powered 8F EDCT automatic transmission, the electric
00:28motor and inverter integrated into the transmission housing in a side-by-side arrangement, and
00:34the 48-volt hybrid battery.
00:37The highly efficient drivetrain was developed by Mercedes-Benz engineers in Germany, according
00:42to proven quality standards.
00:45The drivetrain is designed as a front-wheel drive.
00:48A version with 4MATIC will be available as an option.
00:52The new four-cylinder engine requires little installation space and with its transmission
00:56fits transversely between the steering knuckles.
01:00Further highlights are the compact charge air duct and the near-engine exhaust system
01:04in one-box design, which is prepared for future emissions standards.
01:11The segment turbocharger of the engine sets new standards in terms of performance, combined
01:16with maximum efficiency thanks to a switchable scroll connection.
01:21The engine has a displacement of 1,496 cubic centimetres and will initially be launched
01:28with three output levels of 100, 120 or 140 kilowatts.
01:36For reasons of efficiency, the petrol engine uses a combustion process based on the millicycle.
01:43The comparatively early closing of the intake valves reduces throttle losses and allows
01:48for a high compression ratio of 12 to 1.
01:53Another plus point is the very good NVH behaviour, which is made possible, for example, by the
01:58double bulkhead concept familiar from higher vehicle classes.
02:02The bulkhead insulation has also been extended to the side of the A-pillar and the floor
02:07area.
02:10The M252 engine also has a comprehensive NVH package, consisting of foam and covers to
02:16reduce sound dispersion.
02:20The new 8-speed dual-clutch transmission 8F EDCT is a unique selling point.
02:25It is called EDCT because of the space-saving electric motor, integrated into the transmission
02:31housing.
02:33The power is connected and disconnected with the aid of three clutches.
02:37The ratios of the eight shift stages are widely spread, which benefits efficiency because
02:42the engine operating points can be optimally adjusted.
02:50All eight gears of the 8F EDCT transmission are available in the three different operating
02:55modes, from pure combustion engine drive to hybrid drive using both power units and purely
03:03electric driving.
03:08The electric motor is designed as a permanently energised synchronous machine and has an output
03:14of 20 kW.
03:16The unit is integrated into the gearbox housing together with the inverter to save space.
03:22To increase efficiency, auxiliary units such as the refrigerant compressor are also integrated
03:28into the 48V network and operated electrically.
03:33The 48V battery has an energy capacity of 1.3 kWh and weighs just 22 kg with integrated
03:41DC-DC converter.
03:44Thanks to a P2 layout, the hybrid drive can operate purely electrically in all eight gears.
03:51The electric motor provides intelligent support, particularly at low engine speeds.
03:58Fully electric driving is also possible at high speeds, for example on country roads.
04:07Braking, similar to a battery electric vehicle, is primarily achieved via recuperation, which
04:12is available in all eight gears.
04:16Thanks to the high recuperation power of 25 kW, the battery is quickly recharged.
04:26The elaborate design measures result in a powerful and efficient drive that will meet
04:31the new Euro 7 emissions standard.