[Gray67]

killswitch did an excellent job of describing the reasoning behind getting the AA tune. For me, there are two main differences between the D and DS modes:

* The handling response in DS mode is just beautiful. In D mode, handling is solid, if unspectacular. In DS mode, the car moves like it's reading my mind.
* In D mode, there is a noticeable lag between pressing the accelerator from stop and actually getting motion. It's noticeable enough that when my cousin tried out my bimmer, he asked immediately what that lag was. This lag disappears in DS mode.

It was the latter issue that caused me to finally spring for the AA tune. I have to give a mad shoutout to JLevi Streetworks, who installed the tune for me last week. They did an amazing job, and Brian was possibly the most polite "mechanic" I've ever met. If they did more install work, my money would disappear pretty quickly down their way.

It's now been roughly a week since I got the tune. I had no check engine light issues, something that Brian warned me might happen, and overall the new software was immediately apparent.

I spend 90% of my time in D mode, much like killswitch. The only times I really tend to drive in DS mode is when I'm on the freeway, where the increased pickup and response help me cut through the CA traffic. When I was driving home from JLevi, I kept the car in D the entire time. It was immediately apparent that the throttle lag was gone. I press the accelerator, the car goes. I almost rear-ended cars a couple times because I was used to having that lag there to allow me to slow start. I had to adjust to that change real fast.

Now, a week in, I am really loving driving the car in D. I've not had a chance to spend a lot of time in DS mode, but frankly I don't know that I'll be able to feel as much of a difference. The added HP is not so significant that I'm going to suddenly be racing Porches on the freeway. The car seems to shift around the 2.5K - 3.5K RPM mark, depending on which gear it's in and when I am doing hard acceleration, the shifting is definitely delayed, seemingly into the 6K range. Power definitely seems more evenly distributed across the range.

I've often called my 128 my mistress. Now that I've had the tune, it's like my mistress suddenly got a boob job. :-) I highly recommend this tune to anyone who can afford it - it's something that should have been part of the stock car, and I'm a little annoyed at BMW that I had to go aftermarket to improve my "Ultimate Driving Experience".