John Simister
John on when you could tell a car by the noise it made
Remember when the aural pleasures of cars weren’t all about the rubber?
When I was a very small boy I used to impress my parents by identifying cars before they came into view, just by the sound they made. It was easy enough; the parp of a decelerating Morris Minor’s exhaust note, the breathy two-part harmony of a fanwhining Renault Dauphine, the beating trombone of a Jowett Javelin’s flat-four, and many, many more.
These sonic signatures were an important part of a car’s identity and its character, and car sounds remained quite recognisable up to the early Nineties: the hollow timbre of a Peugeot XU engine’s exhaust note, the crisp efficiency of a Golf GTI’S vocals or the edge heard from a BMW’S straight-six that was absent from a rival Mercedes motor. Then all cars were fitted with catalytic converters, noise regulations tightened and nowadays one four-cylinder hatchback sounds much like another.
No longer is an exhaust rasp simply the result of a camshaft’s very rapid opening and closing rates, no longer is an engine’s sound the accidental result of its architecture. Now it’s all analysed to death.
There are ‘sound symposers’ in induction systems, vibrating diaphragms whose tremblings are directed towards the cabin. Or there are artificial sounds transmitted through the car’s loudspeakers, which is why a top-of-the-range BMW 5-series turbodiesel can sound like a V8.
Even Ferraris, Mclarens and the like have sonic contrivances, such as a micro-controlled squirt of fuel during upshifts to create a racy crackle’n’pop, and great fun they are. But a modern car’s sonic signature is generally built up from a starting point of polite, squeaky-clean quietness, rather than being what’s left when the natural noises are toned down to a level appropriate to a car’s purpose.
There are exceptions, of course, usually resulting from an unusual engine configuration whose aural activities are beyond masking. My Fiat 500 Twinair is one example – it’s one of the reasons I bought it – and a five-cylinder Audi TT RS is another. I am also rare among reporters on modern cars in rather liking the sound of today’s flat-four, turbocharged Porsche Boxsters and Caymans. Most critics bemoan the loss of the ‘chainsaw wail of the iconic flat-six’ etc, but they are mostly too young to remember when Porsches had flat-four engines.
Reasons of rubber
There’s another reason for today’s stricter silencing of engines’ voices: tyres. Cars must pass a drive-by noise test, which is why the last pre-bmw Minis had front radiators: the fan whine emerging from the front left corner caused the Mini to fail the newlyintroduced test when travelling from right to left in front of the microphone. Nowadays, cars have big wheels and wide tyres carrying more weight, and the noise these tyres generate accounts for most of the decibel allowance. It’s hard to reduce that noise, so the engine is made quieter instead.
Next time you’re walking along a road surfaced with Britain’s typically coarse-grain tarmacadam, compare the racket generated by, for example, a BMW X5’s oversized boots with the barelydetectable whisper emanating from a Morris Minor’s dainty treads. Modern cars may be paragons of low pollution as far as their engines are concerned, but tyres have never been noisier as anyone living near a motorway will confirm.
It’s one of many arguments in favour of smaller, lighter cars, cars that the motor industry’s engineers would love to produce if only the public would buy them. Then our battered roads might get some respite, noise pollution from swishing tyres would be reduced – and maybe engines could get their unique voices back.
‘Even Ferraris, Mclarens and the like are fitted with sonic contrivances’ John Simister has been at the heart of British motoring journalism for more than 30 years. A classic enthusiast, he owns a Saab 96 and Sunbeam Stiletto.