[jdmass]

Well, I drove about 250 miles over the weekend, and while the X3 diesel will definitely not be mistaken for the 35i, my initial impressions were confirmed: the diesel can definitely hold its own, and the torque makes up for much of what it lacks in horsepower. I was driving on the highway comfortably at 80mph (that is when traffic will allow -- the ACC is very nice - just set the speed and vehicle spacing and take your foot off the gas).

The only situation that I'm not so sure of would be passing quickly on a 2-lane road. I didn't have any such situations yet, but my sense is that it won't be passing as confidently as the 35i.

The other factor that was very nice is that I've averaged 31 mpg overall while driving pretty normally (i.e. not trying to be super-frugal at all). I didn't check just the highway part, but I guesstimate that it would probably have been around 34 mpg. Next time, I'll enable the ECO Pro Analyzer and collect the data.