Mazda SkyActiv-Drive next-generation 6-sp automaticEnlarge Photo
The key to making this new logic work is a new multi-plate clutch system, rather than a single-disc or piston-based system, to engage or disengage the torque converter with way more finesse than existing automatics. And the clutch pack is controlled by an advanced mechatronics module that's integrated into the transmission case, containing its own microprocessor, software, and direct-acting solenoids.
Traditional automatics have long relied on plenty of torque-converter engagement, both as a way of keeping gear engagement especially smooth, and as a sort of crutch to help keep automatic transmissions more reliable. But as transmissions are designed to disengage the torque converter more frequently and more readily, they can get shaky, said Masamitsu Koike, the powertrain's development manager. So through a data-bus system, the mechatronics module is able to help adjust shift quality—for a change in vehicle load, for instance—to reduce driveline jolts, and it could help prolong the life of the transmission.
Shifts like a racing bike
In the test vehicle, we found that shifts with the new transmission, even moderate throttle, felt nearly instantaneous—quite like a racing bicycle with a high-end derailleur (and a good sign, given the brand's 'zoom-zoom' intent)—with none of the lumpiness or noticeable pause in momentum felt in Mazda's existing five-speed automatic.
The new transmission is slated for all of Mazda's hatchbacks, sedans, and crossovers that are based on front-wheel-drive architecture, so expect it eventually (within a couple of model years) in the Mazda5, Mazda6, CX-5, CX-7, and probably Mazda2 and CX-9, along with the 2012 Mazda Mazda3, which will get very soon—hooked up to the all-new Sky-G direct-injection gasoline engine, this fall.