Article: Daimler developing a three-cylinder motor but says small three-cylinder motors are not good enough for larger Mercedes vehicles

[Sticky]

BMW developed a small 1.5 liter turbocharged three-cylinder motor and it is used in front wheel drive products including Mini (and the BMW 2-Series Active Tourer) as well as the top of the range and the $135,000+ BMW i8 hybrid sports car. Mercedes-Benz intends to produce a small three-cylinder motor as well but unlike BMW they will not be putting it any car with all wheel drive or powering the rear wheels.

Head of engine development Bernhard Heil stated, "We have looked at three-cylinder engines, but there are too many compromises, such as refinement and the savings aren't that significant." Essentially, he isn't a fan and believes the efficiency gain over a small four-cylinder is not worth the compromises. That is why Mercedes-Benz will not replace four-cylinders in their sedans but will develop a three-cylinder for the front wheel drives with a hybrid drivetrain.

If Mercedes developed the i8 you can bet it would not be powered by a puny 1.5 liter three-cylinder as Berhard Heil believes the layout creates too much vibration requiring balance shafts, is noisy, and is inferior to a four-cylinder layout. Mercedes-Benz gets it.

Source

[Stevenh]

What is the story with the motor in the rendering? 2 smaller 2-valve cylinders and a larger 4-valve cylinder?