As automakers slowly shift to hybrid and electric vehicle development, BMW has bucked the trend by continuously developing the diesel engine. During the National Diesel Forum in Germany, BMW CEO Harald Krueger said that future mobility “will definitely depend on state-of-the-art diesels”. Krueger's statement aligns with Daimler CEO Dieter Zetsche's defense of the diesel engine, saying that “Diesel is worth fighting for”.

Krueger said that the modern diesel engine are just as clean, or even cleaner, that equivalent gas engines and called for objective discussions based on facts and scientific evidence. “Three of the four major diesel pollutant issues have been resolved and no longer have any adverse effect on air quality,” adds Krueger.

As part of the diesel rescue plan set by the German government, BMW is offering an upgrade for the exhaust treatment system for older, Euro 5 models. BMW estimates that there are 225,000 cars running on the Euro 5 engine and will offer the upgrade to customers free of charge. The company adds that they do not rig their emissions results as their diesel engines undergo actual on-road evaluation.

BMW's commitment to diesel is seen in the current lineup. The current diesel range consists of the 2.0-liter, four-cylinder unit and the 3.0-liter inline six. The new 2.0 turbodiesel was introduced in 2013 while BMW rolled out an all-new six-cylinder diesel in 2015 and last year, the German automaker revealed a quad-turbo diesel with the inline-six engine. With these new engines, BMW claims that their lineup's emissions are 40 percent lower than the industry average in their home market.

That said, BMW isn't ignoring the shift to alternative energy. The facelifted 3 Series, along with the all-new 5 Series and 7 Series models, can be specified with plug-in hybrid powertrains. There is also the BMW i3 and i8, both of which use plug-in hybrid technology.