Using a 1 Series as a test bed, BMW has unveiled their latest prototype engine in the company's Innovation Days 2015 event. BMW says the direct water injection turbocharger cooling will produce a cooling effect that boosts power and torque, particularly when operating at or near full throttle, while at the same time reducing fuel consumption and emissions.
The technology isn't all new to BMW. BMW has applied water direct injection for an M4 Coupe being used as a safety car in the MotoGP series. It is, however, the first time the 1.5 liter TwinPower Turbo receives the special turbocharger cooling system. One common way to cool down a turbo is by spraying water into the intercooler. BMW has taken a different approach by injecting the water straight into the combustion chamber. BMW claims up to ten percent more power, up to eight percent better real-world fuel economy and engine temperatures lower by 25 degrees.
Furthermore, BMW said the cooling effect provided by water injection reduces temperatures sufficiently to avoid any need to inject additional fuel when operating at or near full throttle and because of the compact three cylinder engine the protoyple also delivers low emmisions and the ability to run on regular gas.
Without the direct water injection system, the 1.5 liter TwinPower Turbo three cylinder normally puts out 130 PS. For this particular engine, power rises to 218 PS, an 88 PS improvement. The engine also gets improved compression ratios which help the engine run more efficiently than its non water-injected counterpart. Because the engine runs cooler, BMW says the system reduces thermal load on pistons, valves, catalytic converter and the turbocharger and helps the engine components last longer.
At the moment, BMW has not announced plans to put the direct water injection system into production.