Yahoo Autos We Drive Toyota's EV Prototype with a Manual Transmission
When we started our campaign to Save the Manuals in 2010, we never imagined a future like this—a psuedo-manual gearbox for an EV. Toyota’s prototype features both an H-pattern gear shifter and a clutch pedal, but although the idea might sound like a spoof, the effort that has already been put into it proves that Toyota is serious amount making a production version.
The idea of a manual-transmission EV is, from a functionality point of view, completely pointless. The flat torque curves of electric motors, especially their ability to produce peak output from a standstill, is key to the drivability of electric cars. Imposing artificial limits on output is always going to reduce overall performance.
Toyota’s logic is that an artificial manual gearbox will bring back some of the engagement that is lost in the electric driving experience. Other automakers have had similar ideas, as Hyundai already let us experience the production-ready Ioniq 5 N’s e-shift system. But the Hyundai system uses steering-wheel paddles to control its synthesized ratios. Toyota has gone one better with both an H-gate shifter and a clutch pedal.
How It Works
The prototype system has, somewhat improbably, been fitted to a Lexus UX300e, an electric version of the small UX crossover. It is able to switch between its conventional drive modes and the manual mode by pressing a new "engine start" button. The new hardware consists of a six-speed shifter with microswitches at each position rather than any physical connection, plus a clutch pedal with an extra-strong return spring to give natural weighting. The clutch is connected to nothing more than a potentiometer. Everything else is done by software.
Our drive was limited to the test track at Toyota’s vast Shimoyama Engineering Center in Japan. It was enough to prove that an EV can give an impressively close impression of a manual gearbox working with a combustion engine, but not an exact one—at least not yet.
The manual EV has a control map which basically replicates the characteristics of a high-output four-cylinder engine, giving a maximum value at a given engine "speed"—this being simulated by software, and relayed by both (in the prototype) an aftermarket tachometer and a synthesized engine note. The gear selected determines engine speed at given road speed and, once the peak simulated revs are reached, the system cuts power progressively, doing a convincing impression of a rev limiter.
The use of the clutch pedal is another complicating factor. Pressing the clutch pedal simultaneously with the gas pedal pressed in the prototype progressively cuts acceleration, as it would on a real manual, with engine revs rising as the load diminishes. However, there were no simulated burning smells.
Simulating the Feel of a Manual
The prototype was convincing even when we tried to fool it. De-clutching leaves the car coasting, and selecting lower gears increases the regenerative braking, simulating the feeling of engine braking. When downshifting, it's possible to rev match by blipping the accelerator in the brief moment when the clutch is fully depressed. The penalty for letting the clutch up too abruptly when selecting a low gear is a bump of shift-shock–momentarily over-revving the electric motors–and a similar lack of finesse when trying to pull away without sufficient revs results in a virtual stall.
It can also simulate the effect of laboring an engine in a too-low gear, with the combination of sixth, full accelerator and an indicated 1500 rpm resulting in glacial acceleration and low-frequency noise through the speakers doing a convincing impression of an engine juddering on its mounts.
Don’t worry: it was still possible to spot the virtual nature of this new reality. The prototype’s gearshift mechanism was too light, clicking between its positions like a video-game controller rather than a real selector. (The engineering team admit it needs more spring weighting.) The simulated engine sounds responded to both revs and throttle position, but were too loud under gentle acceleration to be truly convincing. The engineering team admitted the prototype was actually using a commercially acquired sound map of a Volkswagen Golf.
Nor is there any penalty for getting things wrong. We quickly that realized the clutch pedal is purely optional, with the chance to shift instantly between ratios (even at full throttle) without it. It was also possible to select any gear at any speed, a point made with a deliberate "money shift" into first at 60 mph. This sent the prototype’s rev counter all the way to 10,000 rpm, but didn’t bring any simulation of a real engine exploding into oily shards.
Will It Become a Reality?
To give due credit, the idea of the manual EV felt much less silly after we had experienced it. It is hard to imagine a world where people would choose to psuedo-shift an electric car while grinding through urban traffic or sitting in a freeway jam, but it is possible to see the appeal on a canyon road or a racetrack. Toyota’s engineers echoed the claims made by Hyundai: the need to choose gears can actually help drivers to orient themselves to the different speeds required for each of a circuit’s corners.
Toyota is also working on the idea of offering multiple dynamic characters for EVs, with the ability to not just change soundtrack but also potentially to download different engine and gearbox profiles. So a future EV could have a GR86 mode and a Lexus LFA mode and even a Toyota Tundra mode.
The more practical issue with fitting the system to a production car is the need to accommodate a physical shifter. It's hard to imagine this happening in anything but the most driver-focused cars, despite using a Lexus compact SUV as a prototype. The most obvious candidate to receive the faux manual would be the production version of the slinky FT-Se sports car concept that was shown in Tokyo last week.
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