ZF nine-speed transmission

Up until just a few years ago, four or five speeds were considered sufficient for an automatic gearbox. But over time further ratios have gradually been added for extra responsiveness and economy, so that today eight-speeders aren’t that uncommon.



Now, ZF has gone one better by announcing the world’s first nine-speed automatic transmission for cars. Dubbed the 9HP, it has been designed for front-wheel drive, transverse engine applications, although it can also be modified for all-wheel drive and hybrid powertrain vehicles.

The main benefit of those extra gears is that they allow an engine to run at its most efficient speed more often, and consequently ZF is claiming that fuel savings of 16 per cent are possible compared to the current generation of six-speed automatic gearboxes. That’s a significant improvement, which should help to continue the growing trend for automatic cars to at least match their manual counterparts on economy.



Because the 9HP has been designed to operate within a torque range of between 280 and 480 Nm (206 - 354 lb/ft), it should be suitable for virtually all higher-powered petrol and diesel front-wheel drive cars currently available. However, there’s no word yet on which manufacturers might adopt the new transmission, or what its effect on prices is likely to be.