Porsche has shown that with a little innovation, the manual transmission can remain relevant in a world where regular automatics and newer dual-clutch units offer faster shifts and better economy.
Porsche’s solution was to create a seven-speed manual
by modifying the design of its seven-speed PDK dual-clutch unit, adding a traditional shifter and clutch pedal.
It looks like BMW may be planning a further evolution of the manual transmission, according to a series of new patent filings discovered by Bimmerpost
The patents reveal two new designs for a manual transmission that could have seven or potentially even more gears.
The trouble with having so many gears, apart from the vigorous rowing that would be required, is the damage that could be caused if a driver shifted into an improper gear and caused the engine to over-rev, for example. To circumvent this, BMW has two solutions.
The first, which is the more straightforward, uses a magnetorheologic or electrorheologic fluid to lock out certain gears based on speed traveled or engine revs. Similar to technology used in some shock absorbers, the special fluid reacts when a current is applied and can harden or soften on demand.
The second solution, which is more akin to a full automatic, does away with the clutch pedal completely, relying on an electronic system to disengage the clutch in a similar fashion to BMW’s previous SMG technology. If an improper gear is selected, the system would prevent the clutch from disengaging and perhaps warn the driver by illuminating a light in the instrument cluster.
Of course, we may never see such technology eventuate as automakers often patent designs merely to protect them.