Most streamlined Astra ever: exemplary drag coefficient of 0.285
Clever design: more compact dimensions reduce drag
Attention to detail: rear spoiler, C-pillar and underbody optimized
Increased efficiency: great aerodynamics meet latest generation engines
Rüsselsheim. Lighter, more frugal and more agile – the new Opel Astra represents a quantum leap in the development and targets maximum efficiency. Its design and vehicle architecture also set standards in aerodynamics and continue a traditional Opel strength – when the Kadett E GSi was introduced in 1984 it was the most streamlined hatchback in the world with a cd value of 0.30. Outstanding aerodynamics are closely linked to economical fuel consumption and climate-friendly CO2-emissions – another long-time Opel strength.
A decisive advantage of the new Astra is that it is much more compact than its predecessor is. It is around 2.5 centimeters lower and 0.5 centimeters slimmer, including the more slender wheels. But to make the vehicle as streamlined as possible, precision and attention to detail were also necessary. The engineers paid special attention to the roofline, the C-pillar and the construction of the underbody. The result speaks for itself: the new compact class Opel is amongst the elite of the most streamlined models in its class with a drag coefficient of 0.285.
“We have made the new Astra more aerodynamic than ever before. The drag coefficient values beat the best values achieved by its predecessor across the board. We gained some important knowledge from the tests we conducted in the ultra-modern wind tunnel of Stuttgart University who we have been working with for many years,” said Reiner Weidemann, Head of the Opel Aerodynamics department. “This helped us make the new Astra the most streamlined compact class car ever produced by Opel.”
Design and vehicle architecture: setting standards in aerodynamics
Leaner, smarter and more innovative than ever before – the new Astra epitomizes highest efficiency and demonstrates the next evolutionary stage of Opel’s design philosophy “Sculptural artistry meets German precision”. From an aerodynamics point of view, this means: the new Astra has a drag coefficient of 0.285 with its athletic and dynamic appearance along with the numerous measures taken above and under the outer shell. The new Astra has a total length of 4.37 meters and is roughly five centimeters shorter than its predecessor is. The height has been reduced by 2.5 centimeters to 1.48 meters and the width reduced by 0.5 centimeters to 1.81 meters. These dimensions also have a positive impact on the overall drag, with a cross sectional area of around 0.642 square meters (compared to 0.770 square meters for its predecessor), and thus on fuel efficiency.
However, the art of the exemplary aerodynamic performance is down to attention to detail. The engineers decided to let the roof flow out gently to the rear to avoid any drag. The delicate rear spoiler serves as an effective separation edge that cuts the airflow at the top without creating any disturbing wake turbulences. Even the C-pillar with its small edges was designed to split airflow more efficiently than was the case for the previous Astra, thus reducing drag.
The engineers managed to achieve further improvements by overhauling the design of the underbody. Opposed to many competitors, Opel specifically decided not to look to a full underbody paneling. Instead, all parts were examined and reworked to ensure better airflow. The underside of the car now has airflow-optimized structures and battery attachment, the new rear axle now sits higher compared to the previous Astra, thus no longer providing an obstacle for the air flowing under the car. These measures all play a key part in the exemplary aerodynamics. Expressed in cold figures, the most eco-friendly version of the previous Astra had a drag coefficient of 0.325. The basic version of the new Astra has an outstanding drag coefficient of 0.285. Even the automatic diesel of the new generation with 18-inch wheels easily beats the most streamlined version of the predecessor with a drag coefficient of around 0.31. And that is not all – an even more aerodynamic and frugal ecoFlex version is planned for the future.
Double efficiency: improved aerodynamics meet latest generation engines
The conscious decision not to use a full underbody paneling also means less weight and consequently lower fuel consumption along with reduced production costs. Advantages that have a positive impact on the price – something that can be passed on to the customer.
Combined with the fact that every new Astra will be propelled by an engine of the latest generation with outputs ranging from 70 kW/95 hp to 147 kW/200 hp customers can look forward to a win-win-win situation. All of the new generation engines combine strong performance and economical fuel consumption with outstanding responsiveness while at the same time offering smoothness and low noise levels. For example, with the 1.0-liter turbo and Easytronic 3.0 the new Astra is the most fuel-efficient and eco-friendly gasoline-engined car in its class (4.2 l/100 km in the combined cycle, 96 g CO2/km). That is efficiency à la Astra.
