In the course of performing 100 INKA tests, Audi Quality Assurance has completed a total of 322,500 testing hours, covered more than one million kilometers (621,371 mi) and driven through 2,800 mud tests and 1,900 salt tests. Sylvia Droll, Head of Materials Engineering: “Audi stands for superior build quality, high-quality material appearance and high reliability – even many years after a car is first registered. The INKA test is an essential tool for assessing the quality of our models and for further optimizing our production methods.”
The endurance test covers five phases. First the car is misted with salt in a climatic chamber at 35 degrees Celsius. Next it is exposed to a tropical climate of up to 50 degrees Celsius and maximum air humidity of 100 percent. In phase three, 80 halogen metal vapor lamps, each with an output of 1,200 watts, heat the body to a maximum of 90 degrees Celsius. In the process, the colors in the interior must not fade and the materials must not become brittle.
The fourth phase simulates winter-like conditions at the polar circle. At minus 35 degrees Celsius, a four-post hydropulse machine rocks the car to simulate the body torsion and strain on parts of the vehicle and engine mounts that cars endure on rough roads. In parallel – phase five – test drivers repeatedly drive through specially prepared routes on the open testing grounds.
A total of 12,000 kilometers (7,456.5 mi) are traveled with each model, including driving through saltwater and mud. At the end of the test, the quality inspectors dissect the entire car into around 600 individual parts and check these for weak points.
Audi Quality Assurance conducted the first INKA tests in 2002. Technical Development has been assessing pre-series cars using the same test method for 40 years now.
Fuel consumption of the models named above
Audi A4:
Combined fuel consumption in l/100 km: 6.7 – 3.7 (35.1 – 63.6 US mpg)**;
Combined CO2 emissions in g/km: 154 – 95** (247.8 – 152.9 g/mi)
**Fuel consumption and CO2 emission figures given in ranges depend on the tires/wheels used as well as the engine/transmission version.