As emissions laws get tighter, manufacturers are scrambling to make their cars more efficient. Downsized turbo engines capable of punching well above their weight are the new norm, along with clever gearboxes packing a huge spread of ratios. Kia is the latest brand to ratchet things up a notch or two, launching its first eight-speeder to work with front-wheel drive cars.
Although it's got experience with longitudinally mounted eight-speed gearboxes in rear-wheel drive cars, squeezing one between the front wheels is a very different game. Space is at a premium, because the gearbox needs to slot in under the bonnet, where it rubs shoulders with the engine, suspension and other auxiliary components.
To make it happen, engineers have been working away at the project since 2012. According to Kia, development of the transmission led to the creation of 143 new patents and helped squeeze two more gears and an extra clutch into a unit 3.5 kg (7.7 lb) lighter than the six-speeder it replaces. Crucially, the new 'box is the same size as the one it replaces.
In an attempt to improve overall efficiency, the new unit has been designed to use its hydraulic oil more efficiently, allowing engineers to fit a smaller oil pump. There's also a new control valve body for direct solenoid control of the clutch, which should make for quicker gearshifts. Speaking of quicker gearshifts, Kia is claiming major improvements in shift speed, fuel efficiency and refinement compared to the outgoing six-speed.
Even drivers who couldn't care less about shift speed, smoothness or efficiency will still benefit from the extra ratios. Packing more ratios into a car allows for the bottom gears to be more closely stacked, which improves acceleration and response. Meanwhile, the top gears can be taller without impacting on around-town drivability, essentially delivering the best of both worlds.
The ability to deliver impressive performance without sacrificing efficiency is why Mercedes is making use of a nine-speed gearbox, and Ford has squeezed 10 gears into the new Raptor. It's also why Honda has patented an 11-speed, triple-clutch gearbox. This might be Kia's first front-drive eight-speeder, but it's part of a wider trend that shows no signs of slowing down.
The new gearbox will make its debut in the upcoming Cadenza, before spreading across the range. Kia is also not capping the number of gears at eight, saying its latest effort will "serve as a stepping stone to the development of future advanced Kia transmissions."
Source: Kia
