The full value of modern automated-shift mechanical gearboxes such as ZF's AS Tronic and Volvo's I-shift lies not only in relieving drivers of the burden of waggling gearsticks and depressing clutch pedals. Intelligent decisions about which ratio to select and precisely when to select it are made automatically. Among the first things usually noticed by a truck or coach driver experiencing one of these gearboxes for the first time are how swiftly the system reaches for high gears, how long it hangs onto them, and how adroitly ratios are skipped. It is widely accepted nevertheless that accomplished drivers shifting gears manually can still squeeze more out of a litre of diesel than even the most advanced computer-controlled system, simply because the driver can read the road ahead and use this information to make smarter gear choices earlier. But the most significant gearing decisions of all are taken earlier still, when a new vehicle is being specified.
展开▼
