Endurance test with 16 criteria: the "Sindelfingen rain test"

The rain test at the Mercedes Technology Center (MTC) in Sindelfingen is particularly demanding, and every new vehicle bearing the Mercedes star is required to pass it - whether it has a fixed roof, a soft top or a vario-roof. Extreme quantities of water are used to ensure that the result of the development work is watertight – which is a particular challenge in the case of roadsters or cabriolets. 16 tests must be successfully absolved before approval is granted. Whether during the hose test, when all soft top, door and flap seals are sprayed with a water-hose, the continuous, overnight rain test, the fording test, the icing, swirl and high-pressure tests, or the final session in an automatic car wash – the rain test simulates every conceivable situation that can occur on any continent.

Bench testing and practical trials in all climatic zones

In addition to various test facilities such as the water chamber and the climate/ wind tunnel, the AMG specialists have recourse to test drives in all climatic regions of the world, where problems can be identified and solutions sought. In Laredo, Texas, for example, there is a particularly fine dust which finds its way into practically any gap – and tests the seals to the absolute limit. The compact fabric soft top, which can be conveniently opened and closed in just 11 seconds at the touch of a button, even at speeds up to 50 km/h, must also submit to various tortures. One of these is the standardised soft top endurance test used for all new Mercedes roadsters or Mercedes cabriolets: 20,000 closing cycles on a stationary test rig must present no problem for the hydraulic cylinders, electric motors and joints. There are also 2500 closing cycles while on the move, whether in great heat, icy cold, high humidity or dry desert winds. In this area too, nothing is left to chance – and for excellent reasons: the aim of this enormous effort is to give the customer limitless driving pleasure in their SLS AMG Roadster.

Endurance trial as a final quality check All the optimisation stages have been absolved, and the production tests at the Mercedes-Benz plant in Sindelfingen have been successful, but the developers have still not reached their goal. The quality of the overall vehicle is now the focus of the accompanying endurance trials. These simulate an entire vehicle life under the toughest conditions in accelerated test cycles. The aim is to verify the level of maturity before production of customer vehicles commences.

The endurance testing at a glance:

Long-term testing on a variety of different roads: All the components and systems are tested together in everyday operation. Loaded up to their permitted gross vehicle weight, the test cars are put through a precisely defined test programme on country roads, on motorways and in city traffic.

Endurance testing on heathland: In this case, the developers focus on the durability of the chassis and suspension components, the entire bodyshell and the integral subframe on which the front axle, steering and engine are mounted. The test cars are loaded up to their permitted gross vehicle weight.

"Accelerated" endurance testing: Testing of the entire vehicle, focussing on the powertrain, chassis and suspension. Special features of the AMG programme include 10,000 kilometres on the Nürburgring's North Loop and 10,000 kilometres in city traffic.

Full-load endurance testing: Extreme acceleration and braking manoeuvres with a high proportion of full-load operation, making extreme demands on the cooling, fuel-delivery and braking systems.

Long-term corrosion testing: Corrosion testing of the entire vehicle simulates the toughest dynamic and climatic environmental influences.

Final board approval: All-inclusive verification of the degree of development and production maturity.

World premiere on 13 September 2011, at the International Motor Show (IAA) in Frankfurt/Main

This is an extensive and tightly scheduled programme, and for many an AMG engineer it will only begin to lose its immediacy at the world premiere on 13 September 2011, when the new SLS AMG Roadster is presented to a barrage of media attention at the International Motor Show in Frankfurt/Main.

For further information, please contact: Mercedes-Benz