2008 BMW 135i: Do it. Do it now!
May 22, 2009
You can tell the 135 is different now from the first time you roll into the throttle. It's no lounder, and the revs don't raise any quicker, but it takes fewer revs to get the clutch out smooth from a stop. And then once it's rolling the differences are even more apparent.
I can't speak for the full-throttle gains before and after the new tune as I was driving on public roads, but even in those highly limited scenarios, the DME reflash proved its worth. There's a whole new midrange. There's no turbo lag, there's just a powerful surge that doesn't stop 'till you let off the gas. Why they didn't do this from the factory is beyond me. It's as driveable as it ever was before except now there's more power everywhere. Not like the GSR with unreasonable power surprising you somewhere north of 5-grand, the 135 is smooth and linear instead of peaky. It hasn't reinvented the nature of the 135i, just brought it out into the light a bit more.
If I had a 135 and didn't want to go whole-hog with a plug-in tuner, I'd get this on day-one and just consider it part of the cost of purchase. Again, it should've-- and could have-- come from the factory this way.
Mike Magrath, Vehicle Testing Assistant