Imagine you're driving along and coming up behind you, you spy the large chrome kidney grilles of a fancy looking BMW X5. With glistening paint it looks like it just rolled off the assembly line yesterday, and it may well have. You approach a red light and slow as the X5 pulls out into the open lane to your left. And that's when you hear it: tick, tick, tick, tick. Yup, it's a X5 xDrive 35d. Yuck… a diesel.
It's exactly that experience that may keep a lot of potential diesel customers out of diesel cars.
While its true that in vehicles like the X5, the engine noise is much quieter inside the cabin than outside, some of it still leaks though – but not for long. Along with traditional sound deadening technology like insulation and special surfaces to reduce sound, BMW is now also working on electronic noise canceling technology as a part of its Active Sound Design program.
BMW says its new electronic noise canceling technology can not only be used to just limit sound, but to let the right kind of sound through, matching the engine's noise to how the car is being driven. In fact, BMW recently performed a little research project using cars equipped with its electro-acoustic system and cars without. The results are impressive. "Subsequent test drives showed that test persons, despite measurably identical longitudinal dynamics, judged the driving performance of the vehicle with integrated Active Sound Design to be better. The subjective in-vehicle impression was comparable to the sensation of an accelerating car with a stronger engine."
Normally we'd be worried about a company spending so much engineering talent on making its cars sound faster, rather than go faster. But with BMW you can be sure the latter is not being neglected.
More: BMW's Electronic Noise Canceling Technology Makes Engines Sound Quieter, Better and Even Faster