Conventional paints contain organic solvents that are harmful to the environment. During drying and processing, they enter the air, which then needs to be painstakingly cleaned. In recent years, it has been possible to develop high-quality paints where water largely fills the role of the solvent. This reduces the solvent content of surfacer and base coats at Volkswagen by more than 85 per cent. Volkswagen's paintshops are also using increasingly economical, fully automated application techniques. Processing requires a high level of professionalism, precise air conditioning and strict cleanliness in the painting facilities.
1. Fuel consumption Golf R in l/100 km: urban 8.2-8.0 / extra-urban 6.6-6.4 / combined 7.2-7.0; CO₂ emissions combined, g/km: 164-158; efficiency class: D
Wheel speed sensor
Wheel speed sensors measure the speed of the wheels or a distance or angle covered per unit of time. A wide range of systems operate using the wheel speed sensor signals. Accordingly, the mode of action of the anti-lock brake system, Traction Control System and Electronic Stability Control depend on wheel speed information. Navigation systems also benefit from these sensors’ signals. They use them to calculate the distance covered.
Wheel speed sensors are broken down into what are known as passive and active sensors. Today, active sensors dominate, thanks to their technical properties such as accuracy and compact size. Active sensors require an additional source of electricity to operate, while passive sensors manage without an external energy source.
The WLTP (Worldwide Harmonized Light Vehicles Test Procedure) has replaced the NEDC driving cycle. The aim of the changeover is to be able to map out vehicles’ exhaust gas levels and fuel consumption more realistically. The procedure involves a different driving cycle and more stringent test specifications and is intended to make results comparable worldwide. WLTP will be the legal basis for European exhaust gas legislation in future. Since 1 September 2017, the exhaust gas and consumption levels have been indicated for all new engines and models. From 1 September 2018, exhaust gas and consumption levels must then be indicated according to WLTP for all (new) vehicles.
WLTP driving cycle
In WLTP, the driving cycle is measured at a maximum speed 10 km/h higher than that which applied for NEDC. The measurement comprises four phases: up to 60, 80, 100 and 130 km/h. At around 47 km/h, the average speed is also significantly higher than for NEDC (around 33 km/h). The WLTP driving cycle lasts around 30 minutes, while the NEDC only takes 20 minutes. The distance is 23 km instead of 11 km. For the test procedure, a temperature of 23° C is required in the test chamber. Previously, for NEDC, it was 20 - 30° C. The switching points are not longer statically prescribed but can be freely selected for a specific vehicle. Unlike in NEDC, individual pieces of special equipment are taken into account in WLTP for weight, aerodynamics and electrical system requirements (no-load current). Special equipment that consumes electricity, such as the air conditioning system or seat heating, stays turned off for the test procedure.
In WLTP, there are three power-weight classes:
- Class 1: up to and including 22 kilowatts per 1,000 kg of vehicle weight
- Class 2: up to and including 34 kilowatts per 1,000 kg of vehicle weight
- Class 3: 35 kilowatts and over per 1,000 kg vehicle weight
Vehicles typically available in the EU usually have power-weight ratios over 34 kW/t and therefore fall almost without exception into class 3. Vans and buses may also belong to class 2.