With the introduction of the 4 Series convertible and the 2 Series, there remains only one naturally aspirated BMW currently being produced for the American market. That car is of course the M3 convertible which also ends production within weeks. While the V8 in that M3 and the the N52 inline six are two engines miles, they had one commonality – they represent the last of a classic BMW approach that was, at one time, the heart of the brand: free revving naturally aspirated engines. And now in just a few years time that approach has been wiped from BMW’s line-up.

The N52 (found in the 1, 3, 5 series, X3 and Z4) is a classic BMW inline six with a block cast with magnesium and aluminum for the crankcase. It’s not endowed with a lot of power (245) but it makes up for it with a turbine smooth delivery only an inline six could have. It’s eclipsed by its successor in about every way (except for power) and yet we can’t help but miss it already.

On the other end of the spectrum we have the S65. Derived from the E60 M5’s V10 engine (BMW chopped a couple cylinder off to get the V8) the S65 was admired for its ability to rev and tingle the senses of the driver all the way to redline. It may not adhere to all of the classic inline six philosophy but it’s one of the best engines ever put into mass production taking International Engine of the Year awards for the 3.0 to 4.0L category 2008 through 2012.

And now we have nothing but turbos – The N20 and N55 being the workhorses of the US market in particular. In Europe (and especially the UK) it’s the four cylinder diesels that sell in huge numbers. I suppose it makes saying goodbye to the NA engines a little easier knowing that the new crop of power plants are so good. More power, higher ability to rev and better efficiency across the board. But like mechanically boosted steering, there’s something lost in this progress that will always make us yearn for the purity of the un-boosted engines.

Will you miss the NA engines? Sound off in the comments section.