Flex4 may sound like something sold during the 3 a.m. hour on advertorial television, but it's really Magna's part-time all-wheel drive system that offers the benefits of AWD with lower emissions than standard AWD. How? Because Flex4 can disengage the power going to the rear wheels when it determines that it isn't needed, changing the vehicle to a more-efficient two-wheel-drive ride. The AWD is also engaged every time the vehicle stops and, most of the time, when the vehicle goes above 30 miles per hour, the rear wheels disengage. Whenever the system detects a slippery road, the AWD reconnects in a few hundred milliseconds. The AWD also engages if there is a "yaw event" (i.e., a hard lane change). The benefit? A fuel economy improvement of around .8 to 1 mile per gallon compared to standard AWD systems.
Flex4 on display at the SAE World Congress was just a prototype, and is being designed to be purely automatic but it could theoretically be driver-selectable. At this stage, too, there is no estimated cost for such a system, but Magna knows that OEMs will be looking for ways to add AWD capability to vehicles even as CO2 emissions regulations get tighter and tighter. As a Tier 1 supplier, Magna says it is ready to start production of Flex4 now.
Magna has been working on Flex4 for at least two years, but not a lot of information about the system is available online. We did find one video about Flex4, which we've pasted down below, but it happens to be in German. Still, you can see Flex4 at work in all it's animated glory.