2008 BMW 135i: DME Tune Reflash Driving Impressions
June 08, 2009
Being the guy who shepherded our longterm 2008 BMW 135i to and from DME Tune, the test track and all over southern California, I've spun up quite a few digits on the odometer in its newly invigorated state. And here my impressions.
The first thing I noticed immediately after DME Tune reflashed it is that driveability around town is actually better than stock. In these off-boost conditions, the 135i now accelerates more brightly, as if it just downed a half-serving of espresso. Miata guys would describe this as "crisp."
Then, when you lay fully into the throttle, the 135i pulls with a vigor that in no way can be mistaken for stock. There's loads of midrange grunt on tap, and the redline comes up right quick. And as other editors have noted, there is indeed no downside to the way this thing now drives--it's all gravy and no lumps.
An observation: the oil temperature gauges now stabilizes at about 10-20 degrees cooler than it did with the stock flash. Could it be that the DME Flash also includes tweaks to the (electronically controlled) thermostat?
Also, I'm convinced that the performance test results we measured for the reflash don't fully represent what this car can do. The reason? It was about 20 degrees hotter when we tested the reflash.
Now, we don't weather-correct turbocharged cars since they largely compensate for ambient conditions. However, when you modify a boosted car, you eat up a bit of this ability to compensate. I'd really like to re-test in in weather conditions that more closely match the test conditions of the stock flash for a more apples-to-apples comparison.
Hmm. With the variables associated with acceleration testing, maybe we just need to suck it up and do a full-on dyno geek-out comparison of stock vs reflashed.
That's a lot of work, though. And I'm busy enjoying this 135i.
Jason Kavanagh, Engineering Editor @ 22,620 miles.