While it plans to launch 10 new electric cars by 2025, Mercedes-Benz is far from done trying to improve the efficiency of internal-combustion engines.

The German luxury automaker is giving its lineup of engines a major overhaul, in fact.

It plans to introduce a new family of 4-, 6-, and 8-cylinder engines, with the new engines starting to arrive in the U.S. in 2017.

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The first car to receive one of these new engines will be the updated S-Class, which will likely be sold as a 2018 model.

The entire family of new engines is based on a modular design, with each cylinder displacing 0.5 liter.

The smallest engine confirmed so far on the new architecture is a 2.0-liter inline-4.

Mercedes-Benz belt-driven starter generator (RSG)

Mercedes-Benz belt-driven starter generator (RSG)

Extensive use of aluminum makes the engine lighter than its predecessors, according to Mercedes.

It uses a 48-volt belt-driven starter-generator in place of a traditional starter motor and alternator.

This setup is better able to work with engine start-stop systems, and also enables to engine to be turned off while moving for "coasting."

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The engines will also use particulate filters, emissions-control devices already commonplace on diesel vehicles that haven't historically been used on gasoline engines.

The 4-cylinder engine has a maximum output of 134 horsepower per liter of displacement, meaning it could produce up to 268 hp in total.

Next up in terms of size is a 3.0-liter six-cylinder engine, which adopts an inline configuration, instead of the V-6 format favored by Mercedes since the 1990s.

Mercedes-Benz 3.0-liter inline-6

Mercedes-Benz 3.0-liter inline-6

This engine will use an electric turbocharger, which employs an electric motor to drive a compressor that forces more air into the combustion chambers.

That function is performed by exhaust gases in conventional turbochargers, but electric motors can spool up more quickly, eliminating delays in response known as "turbo lag."

The inline-6 will also feature a more substantial starter-generator, sandwiched between the engine and transmission.

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This will allow the starter-generator to provide supplemental power to the wheels, and it will provide ancillary power for accessories as well.

Mercedes claims the starter-generator can provide 20 hp and 162 lb-ft of torque under high-load situations.

Total output for the inline-6 is expected to be up to 408 hp and 368 lb-ft.

Mercedes-Benz 4.0-liter V-8

Mercedes-Benz 4.0-liter V-8

Rounding out the new engine family are V-8s based on the 4.0-liter twin-turbocharged unit already used in Mercedes-AMG performance models.

These engines replace a series of 4.7-liter V-8s, and will produce over 476 hp and 516 lb-ft of torque in models with the "550" designation.

Mercedes will add cylinder deactivation, which can switch off up to four cylinders under light loads to save fuel.

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The new Mercedes family of engines shows the lengths to which carmakers must now go in order to wring more efficiency out of internal-combustion engines.

While gasoline and diesel engines will never match the zero tailpipe emissions of battery-electric or hydrogen fuel-cell cars, they will likely endure for the forseeable future.

That means manufacturers must continue to make them more complex, with more new efficiency-related features, to meet increasingly stricter global emissions standards.


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