“American drivers are spoiled in winter,” laughs John D. Zalewski. The engineer who works at Magna who is responsible for the important powertrain department of the global supplier, explains that his compatriots hardly ever put on winter tires during the cold season. “The majority are on the road with all-weather tires because they expect the roads to be perfectly cleared and salted at all times. What did we do in the past with ice and slippery snow, before all-wheel drive became socially acceptable? " In the meantime, SUVs and crossovers have become very popular as traction masters on both sides of the Atlantic. They just have disadvantages. On average, they consume up to 14 percent more fuel than vehicles driven purely via the front or rear axles (2WD). In addition, the higher exhaust gas values generated in this way will also become a problem in the successful segment in view of stricter CO2 limits in the future. These are explosive tasks that the powertrain experts of the specialized suppliers have to face in competition with the competition.
“We know,” says Zalewski, “that in a good 90 percent of cases the all-wheel drive (AWD) in an SUV is not called up at all. However, the entire technology for this is virtually inoperable on board, causing more consumption and friction losses. " Magna's answer to this phenomenon is called Flex4 and for the first time offers a completely decoupling AWD. Disengageable all-wheel drives are also supplied by the main competitors BorgWarner and GKN (for example in the Land Rover Evoque). But in contrast to conventional systems known as Disconnect, such as in the new Jeep Renegade, the intelligent unit developed by the Austrian-Canadian service provider switches from all-wheel drive to real two-wheel drive if necessary.
Two additional coupling units ensure that the four-wheel drive train is completely separated from the non-driven axle while driving. Compared to pure 2WD models, according to Magna, this would only result in an additional consumption of two percent. If the intelligent electronics detects, for example, changed road conditions or fast steering maneuvers by the driver, the feedback to propulsion takes place on all fours in the blink of an eye - in two to three tenths of a second. The new system is said to weigh less than 50 kilograms.
Flex4 technology will go into series production in late 2015 and debut in a new vehicle in 2016. The supplier, who researches and develops for brands such as BMW, Mercedes, Maserati, Jaguar and subsidiaries of the VW group, naturally has to maintain absolute secrecy. But in Brimley, at the northernmost tip of the US state of Michigan, the technology hidden behind a brand name could be tested before the start of series production under virtually Scandinavian winter conditions. A Land Rover LR2 was used as a test vehicle for the North American market, which had to cope with the typical ice and snow chicanes.
An extreme winter rally pilot might have managed to put the clever system - figuratively speaking - on black ice. But both in slalom through tightly set pylons and in fast cycling, Flex4 worked in the barely noticeable blink of an eye. In the SUV, which once operated as Freelander in Europe, the torque distribution between one and two axles actually worked as seamlessly as if the vehicle were being pulled by a steel cable. Even on the prepared chess board made of dry and icy surfaces, the Freelander did not slide sideways when starting off, but spread his strength at lightning speed and unnoticed by the driver to push himself forward.
Magna's Powertrain portfolio also includes 4WD developments such as Ultimax, which is used particularly in large US pick-ups, or the ProActive module, which is used in the Mercedes-Benz GLA, for example. High-class customers of the service provider such as BMW or Mercedes have the selectable all-wheel drive. But Flex4 could also be interesting for manufacturers of smaller SUV or crossover models, because many customers shy away from the additional costs of four-wheel drive when ordering.
Author: Alexandra Felts / SP-X