The humble automatic transmission has come along in leaps and bounds over the year, and modern systems are often more efficient than their manual equivalents.
For the manual gearbox itself, economy is still very much down to "the nut behind the wheel", so anything that optimizes a driver's shift points should result in gas mileage savings.
One such device has been developed by Ford engineer Zachary Nelson.
Using Bluetooth data transfer and the vibration motor from an Xbox 360 controller, Nelson has invented a shifter knob with haptic feedback technology--vibrating to let the driver know when to change gear.
The shift knob uses open source OpenXC technology to transfer data from a car's on-board diagnostics (OBD) port via Bluetooth to the shifter. In effect, it's transferring the visual gear shift indicator feedback already found in many modern cars into a haptic signal.
While the car Nelson is using in the video (via Autoblog) is a Ford Mustang, there's no reason it couldn't also be applied to any vehicle with a manual transmission.
The vibrations can be set to alert a driver when to change gear whether driving quickly or driving for economy, so it's just as useful for the wannabe racer aiming for the red line as it is the hypermiler eking every last mile per gallon from their tank--all without taking their eyes off the road.
On first glance, we can see a few small issues with the technology. The first would be how a driver should interpret vibrations from the shifter--a different frequency would be needed to encourage a driver to shift down, rather than up for example. This probably wouldn't be difficult to implement.
The second is that it does require a driver to keep his or her hand on the shifter, something we'd generally discourage. It can result in extra wear to linkages if you regularly put pressure on the stick, but also means having one hand off the wheel the whole time, which could be considered a safety issue.
Still, that's why these things are prototyped, so it may be some time before we see the vibrating shifter in production.
And in the meantime, your car's gear shift indicator--or indeed your own experience with the vehicle--should be all you need to help you select the right gear.