The Best Of TTAC: The Art Of Noise

[Editor’s note: This piece was originally published in February 2009, and like so much of TTAC’s content, it’s timeless enough to deserve another moment on the front page. Enjoy!]

Rolls-Royce used to advertise the fact that their cars were so quiet that the loudest sound you heard was the [analog] clock ticking on the dash. Who said the British don’t do hyperbole? As a quiet car connoisseur, I’d have to say a Clinton-era Cadillac provided the quietest ride I’d ever experienced; if the time was one of peace and prosperity, then so was the car. Nowadays, automakers are telling us that their cars are quiet, or at least quieter than ever before. I’m not buying it. A number of recent drives have been notable for their aural uncouthness. So I set out to find the truth about automotive sonic signatures. Has nostalgia dimmed my memory (if not my hearing)? Is progress on the noise suppression front been less impressive than industry propaganda would have you believe?

The German buff book Auto, Motor und Sport recently opened its archives to tightwads. I’ve spent a few hours perusing the decibel stats. To save space, the table I’ve compiled only deals with interior noise at about 80 mph (130 km/h). It’s a civilized speed (at least here in Germany) at which one would want to be able to hold a civilized conversation, even with a back-seat passenger.

Car and model year Interior noise in dB(A) at 80.78 MPH

1995 BMW 728i 66

1995 BMW 523i 66

2003 BMW 730i 66

2009 BMW 330d 68

2009 Mercedes C350 CGI 68

2009 Renault Megane dCI 69

1996 Mercedes C280 69

2008 Mercedes C250 CDI 69

1996 Citroen XM V6 69

1995 Audi A6 2.8 69

2006 Mercedes E220 CDI 69

2006 BMW 520d 69

2000 Ford Mondeo 2.016V 69

2009 Ford Mondeo 2.5 Titanium S 70

2006 Audi A6 2.7 TDI 70

1996 Mercedes E230 T 71

2003 Toyota Camry 2.2 71

2009 Toyota Auris 2.0 D-4D 71

1995 Honda Civic 1.5i VTEC-E 72

2009 Honda Civic 2.2i-CTDi 72

2002 VW Golf 1.9 TDI 72

2009 VW Golf 2.0 TDI 72

2009 Opel Astra 1.9 CDTi 72

1996 Opel Astra 1.6 16V 73

2003 Toyota Corolla Compact 1.4 73

2009 Porsche Carrera 73

1995 VW Golf Cabrio 1.9TDI 73

1996 Ford Mondeo 1.8GT 73

1995 VW Golf CL 1.6 74

1995 Mercedes E230 74

2000 Toyota Corolla 1.6 76

2009 Ford Ka 76

1996 Renault Megane 2.0 16v 76

In some market segments (e.g., executive cars), you have to ask: where’s the progress? What, for instance, has BMW been doing since 1995? Most cars have gotten much heavier. You think that the extra heft might include some extra soundproofing. But plenty of today;s lumbering leviathans are hardly quieter than their sprightlier predecessors. What does Mercedes expect us to think about zero improvement for the C-Class in twelve years?

VW’s press release for its newest Golf calls it ”the quietest Volkswagen Golf since the model series began” characterized by “first-class acoustic properties.” Yes, “a special sound-damping film in the windshield reduces driving noises, as does the newly developed seal design on the doors and side window guides.”

Significantly less wind noise is generated by the outside mirrors due to their new shape. Furthermore, special modifications were made to better isolate the engine and passenger compartments from one another acoustically. Quiet rolling tires and new engine bearings round out the noise reduction program.

Empirically, the new Golf offers an improvement of 2 dB in three car generations and thirteen years.

Small cars have gotten much better, though. Corollas and Renaults used to be noisy boxes. Intense competition in the compact field seems to be working its magic. The Auris (the more-advanced, Euro-market Corolla) is a quite soothing small car, and the Megane’s low level of noise is a marvel.

Really small cars, like the Fiat Panda or the Ford Ka, are still noisy, and are thus for me un-purchasable vehicles, since they (driven quickly) generate a clamor louder than Occupational Noise Exposure standards would allow.

A noise level of 70 dB(A) seems to be hard to crack in cars for regular folks. But this is, to my mind, a pretty tolerable loudness, unreachable a few decades ago.

You’d think with advanced computer firepower, more precise manufacturing tolerances, double-lip door seals and multi-laminate windows, cars would generally be much quieter than in the 1990s. Why aren’t they? Remember one dirty secret of the car industry: usually, each successive generation of a car is cheaper to manufacture. Cost-cutting means that progress is slow—unless the market actively demands progress.

Or unless the car maker is genuinely forward-thinking. In terms of quietness, the only revolutionary car in recent years may be the Lexus LS 600h, which claims 60db at 60MPH.

On the other hand, where are the technical advancements we’ve been waiting for? Active noise cancellation, once seen as the answer to all things cacophonous and found in Honda’s cylinder de-activating Odyssey minivan, seems to be a pipe dream. This despite the fact that BOSE et al. have been promoting its benefits for years, and Germany’s Fraunhofer Institute says it’s working on a useful system.

And what about a microphone-based, user-friendly and effective interior intercom? I’m tired of shouting at back-seat passengers (although it can be useful in the case of children, dogs and back-seat drivers). A car that used electronics to help you converse with everybody on board, without raising your voice: now, that’s something that would lead me to a showroom, and to ponder a purchase.