TURIN – A new line of 3-, 4- and 6-cyl. modular engines, in both gasoline and diesel configurations, will enter volume production next year when BMW launches a new wave of vehicles fitted with the innovative powertrains.

BMW first unveiled plans for its 3-cyl. modular turbodiesel at the 2009 Frankfurt auto show when it presented its first Concept i8 Vision high-performance 4-seat sports car.

At this month’s Paris auto show, the engine family’s gasoline 3-cyl. is being shown in the German auto maker’s Concept Active Tourercross/utility vehicle, which is believed to be close to the production model expected to hit the market within the next couple of years.

In a limited test drive of BMW 3-Series and 1-Series cars fitted with the new gasoline engine, the 1.5L 3-cyl. revs up enthusiastically and delivers power smoothly, producing the exhaust note of a sports car. Noise, vibration and harshness levels are minimal, thanks in part to the use of a balance shaft and torsional-vibration damper that keeps the engine balanced even at low rpm.

BMW says that when mated to an optional 8-speed automatic transmission, the new powerplant delivers “more driving pleasure for less fuel,” claiming a 5%-15% improvement in efficiency compared with its current engines, depending on driving style.

All six members of the new family feature displacements of 0.5L per cylinder, with output of some 40-67 hp and 44-66 lb.-ft. (60-90 Nm) of torque per cylinder in gasoline versions and 27-60 hp and 55-74 lb.-ft. (75-100 Nm) of torque for the diesel units.

Ultimately, the 3- and 4-cyl. engines also will be offered in smaller displacements of 0.4L per cylinder, increasing family members from six to 10, with total displacements ranging from 1.2L to 3.0L.

The modular concept adopted by BMW is simple: The smaller engine is indeed half of the 6-cyl. and the 4-cyl. is two-thirds the size of its bigger brother. The design is such that the 3- and 4-cyl. units can be mounted north-south or east-west in nearly every new BMW. They are ready for rear- or front-wheel drive, as well as for Active Hybrid versions of all new models.

Each of the engines is installed into the vehicles in an identical way, making even more body-style derivatives possible in the future.

“The concept will allow considerable savings to be made in development, integration and production, at an increased level of quality,” BMW says.

In addition to sharing mounting points, the engines connect in the same way to the cooling and heating and air-conditioning systems. Intake and exhaust manifolds also mount identically. Compared with current models, the number of possible combinations in these areas is decreased by about half.

All of the power units have the same “cold” intake and “hot” exhaust sides, which is why the 3- and 4-cyl. units are suited to both longitudinal and transverse mounting in future BMW and Mini models.

The modular architecture of the new family also allows for unprecedented production efficiency and economies of scale. BMW says the three gasoline engines share 60% of their parts, as do the three diesel engines. About 30%-40% of the parts are common between the gasoline and diesel groups.

Both gasoline and diesel engines will be produced on the same production line for the first time, allowing forrapid response to changing market conditions.