Subaru has filed two related patents with the U.S. Patent Office that repositions the front trunk, or “frunk,” above the front drive motor to optimize space in electric vehicles. The designs offer unique solutions for sliding the storage unit forward when the hood is opened, making it easily accessible while preserving motor room beneath.
Rethinking Frunk Safety and Accessibility
While some EVs feature deep front trunks (frunks) that extend down to floor level in front of the drive motor, Subaru highlights a significant safety concern: in a collision, the frunk could potentially impact the motor. Since the motor is typically compact, low-mounted, and positioned closer to the rear of the engine bay between the front wheels, Subaru proposes relocating the frunk directly above it.
This positioning would move the storage area out of the crumple zone, enhance safety, and allow for shorter front-end designs. However, this also introduces a new challenge: with the frunk located farther back, it becomes more difficult to access from the front of the vehicle.
Solution: A Movable Frunk
Both of Subaru’s patents place the frunk on top of the drive motor, far back in the nose section, close to the windshield of the vehicle. To solve the access problem, the frunk then moves up and forward toward the person standing in front of the vehicle. The difference between the patents is the way in which the frunk is moved:
- The first patent attaches the frunk to the hood by a system of levers and gas struts to lift it up and move it forward when the hood is opened.
- In the second patent, the frunk is not attached to the hood, but is moved from below with levers and rams attached to the underside of the frunk.
Two Approaches to Frunk Accessibility
Both of Subaru’s patents aim to solve the same problem: making a rear-mounted frunk easier to access from the front of the vehicle. One design mounts the frunk directly to the underside of the hood, bringing it forward when the hood is opened. While clever, this mechanism appears complex and potentially heavy, requiring a reinforced hood to safely support the frunk—especially when fully loaded.
The second approach involves a sliding or lifting mechanism that moves the frunk forward independently. Though likely more practical and structurally sound, this solution may take up valuable space beneath the frunk, limiting its overall capacity.
Whether either system justifies the added cost and engineering complexity remains to be seen.
