[ezmaass]

Nothing is as wonderful as a BMW NA inline 6. Too bad many owners today who are new to BMW may never experience them. My first BMW was a 2001 325i - inline 6 produced 184hp. It was nothing to write home about, but it was more than sufficient for the size of the car, and it was buttery smooth. I put about 125k miles on that car over about 6.5 years before buying a 2007 335i. While still smooth, and it had that great "surge" from its 300hp TT engine, it was no longer linear and predictable.

After 89k miles and about 6 years, I sold the 335i and bought my current 2014 550xi. It's by far the most powerful of the BMWs I've now owned, but its engine is nowhere near as sweet as my old 2001 325i. The TTV8 is, like many modern forced-induction engines, non-linear and just not as smooth.

In a world where everyone is going turbocharged, a beautiful naturally aspirated engine is a rare and special thing. It's one of the reasons why I love my R8 (and will never sell it) - the power delivery reminds me a lot of my old 325i... granted, with a lot more power, crazy sounds, etc... but linear, buttery delivery of power allows you to dial it in or out surgically with your right foot... something you can never do with a turbocharged engine.

All of that said - I'd say ABSOLUTELY buy the NA engine car. I've kept my last two BMWs for considerable mileage, but the 550xi won't be around as long - I just don't trust it'll be reliable, and while it has tons of gadgets and power, it just honestly isn't as "sweet" as the old inline 6's. I think the F10 would have been great with a naturally aspirated engine putting out around 300hp... something we're never going to see again, though, from BMW (or probably anywhere!).