The new C-class is Mercedes’ most rigorously tested model ever, as Hugh Hunston discovers

Next June’s UK sales release of the new C-class gives Mercedes the opportunity to provide proof that product quality and reliability “problems or issues” are being exorcised.

At the heart of the company’s a pre-launch campaign offensive are intensive media briefings on how thoroughly tested the upcoming compact family saloon has been over the past three and a half years – Mercedes’ most rigorously proven model in its history.

A total of 280 prototype and pre-production models have completed a daunting ritual that’s taken in routes in urban Tokyo and Arctic Finland to dusty Namibia and sweltering Dubai.

Test drivers, their heavily disguised matt black C-Classes crammed with telemetry equipment, covered 15 million miles on virtually every conceivable surface and in myriad climates and temperature extremes.

Mercedes does not take computer simulation as far as some rivals, although that saves time, money and effort in the early stages.

The company’s process involves roads, tracks and test rigs, which Bruno Seufert, senior development engineer for chassis durability, says reflects “our increasing focus on long-term quality, robustness and reliability. There were problems and our response has been to tackle them by consolidating a corporate quality culture and philosophy”.

Torture test

At the core of the company’s multi-faceted operation has been a ‘torture track’ test, which proves there is a future in the automotive past. Called the Heide endurance course, its potholed and cobble-stoned surfaces reproduce faithfully the bone-jarring track in northern Germany’s historically pivotal northern Luneburg Heath (Heide).

The original rough and tough route was the setting in the 1950s for less sophisticated chassis tuning, but its re-incarnation remains entirely relevant.

This four-week driving discipline equates to 186,000 miles of nominally everyday motoring, but to be able to monitor more accurately the stresses and strains imposed on bodyshell, powertrain and chassis, the Heide terrain’s effects are transferred digitally to a £2.7m ‘super shaker rig’, the ultimate in a collection of 160 rigs.

This shake, rattle and roll ritual, with the car bucking and twisting, is on a piece of apparatus founded on a 24,000kg concrete block, which itself is decoupled and air sprung independently from the technical centre building.

Some 70 hours of laboratory Heide punishment apparently has the same clinical effect as the month-long open-air driven testing.

Smaller scale but no less brutal endurance runs relate to individual suspension units, down to rubber bushes and ball joints, in a variety of hostile environments and destructive substances. These vary from 90-degree C axle component tests, simulating a real Tokyo traffic grind, to spraying pivotal parts with ice cold filthy water and hot sand dust.

Instilling that rediscovered corporate quality and durability ethos is extending to a final 10m-mile pre-production appraisal conducted by 450 employees in so-called everyday conditions.

This more mundane urban and rural driving environment often throws up niggling faults, which sophisticated multi-million Euro proving programmes somehow miss.

Admittedly, much of Mercedes’ quality malaise revolved around advanced electronics, and a software interface, but by minimising the noise, and particularly vibration and harshness within the C-Class’s bodyshell, the digital nerve centre should remain less stressed.