- New layout for a 2-speed might be light and compact while maintaining efficiency
- Could potentially allow strong launch with a lower-cost motor unit
- Idea might be due in future Lucid EVs, or engineers might still be pondering it
The Lucid Air electric sedan already achieves impressive efficiency with its existing drive unit, but the automaker might be considering a 2-speed transmission for possible future use, a patent filing indicates.
The patent, first spotted by Motor1, was filed in 2023 and looks to build on the current drive-unit setup, which uses two coaxial planetary gearsets to provide the necessary reduction from motor speed to wheel speed while keeping packaging compact.
It describes the use of one or more planetary gearsets to achieve two gear ratios, with a tapered gear surface on each respective gear plus a system of one-way clutches to switch between them.
Most electric cars do without multi-speed transmissions, but they’ve been a topic of discussion for some time. The original Tesla Roadster was supposed to use a 2-speed gearbox, but that was substituted for a fixed reduction-gear setup after prototypes failed to handle the motor’s copious torque.
Lucid 2-speed transmission. – U.S. patent
Lucid, in the patent application, somewhat parallels explanations provided to Green Car Reports in the past from CEO and CTO Peter Rawlinson about why it hasn’t yet used a multi-speed unit. In the filing, the company’s authors explained that the gearboxes already used in a few electric-vehicle models “are complex mechanisms that take up significant space, they may have low efficiency and/or deliver low initial torque, and they place a significant inertia load on the drivetrain (e.g., an excessive jerk when shifting).”
If such a component doesn’t take up initial space or reduce efficiency, while allowing smaller, lighter motors, incorporating them with Lucid’s upcoming Atlas drive unit could pay off in averted cost and weight—although the company has made no claims as of yet that this patent has anything to do with Atlas.
Next-generation Lucid Atlas drive unit – bound first for future midsize EVs
“Lucid continuously explores new ideas and develops technological innovations that could further advance our electric vehicle technology and help accelerate humanity’s transition to sustainable transportation and energy,” the company stated, in response to Green Car Reports’ question as to whether this patent might be connected to Atlas and thus its future midsize models, initially. “Protecting unique IP is a typical part of the innovation and development process, though we can’t speak to potential future applications of specific patents.”
2024 Lucid Air
The Porsche Taycan has a 2-speed gearbox for its rear wheels, which Porsche has said helps balance acceleration and high-speed efficiency. The gearbox has a low gear that helps deliver more torque from a standing start, while keeping the rear motor and power electronics cooler. The high gear automatically engages at a certain speed threshold, or when the drive eases up on the accelerator (manual shifting isn’t possible), and driving it gently can skip the low ratio entirely.
In dual-motor versions of the Model S, Tesla has used motors with different gearing to achieve similar goals. Volkswagen is also confident that it can find other ways to maximize efficiency. In a recent interview with Green Car Reports, Kai Grünitz, VW’s head of global research and development, said the automaker still has no plans for 2-speed transmissions in EVs.
Mercedes-Benz, on the other hand, is using a 2-speed transmission in its next-generation MMA platform, which will underpin four compact models starting with the 2026 Mercedes CLA, which will be sold with all-electric and hybrid powertrains. And perhaps Lucid will follow through and include an additional gear ratio in some of its future EVs as well.
–with reporting by Bengt Halvorson