What: Audi EP4 Concept
Model Family: NSU Prinz 4
Debuted:
Year: 2023
Number Produced: One-off concept (2023)
Model / Generation Code(s): Prinz 4
Chassis / Matrix: Modified Audi A1 floor structure
Assembly: Neckarsulm, Germany
Class: Electric restomod concept
Body style: 2-door compact coupe (based on NSU Prinz 4)
Layout: Rear-mounted electric motor, rear-wheel drive
Power output: 176 kW (240 hp)
Battery source: Audi Q7 TFSI e quattro components
Motor source: 2020 Audi e-tron components
RELATED
Concept Cars:
Road Cars: NSU Prinz 4
Race Cars:
OVERVIEW
The Audi EP4 Concept is a one-off electric reimagining (a.k.a. “restomod”) unveiled in 2023 at Audi’s Neckarsulm site. Created by twelve apprentices, the project reimagines a 1971 NSU Prinz 4 as a high-performance battery-electric vehicle. The EP4 was developed to mark the 150th anniversary of the Neckarsulm production site and debuted during a company Family Day event.
The name “EP4” combines “E” for electric drive and “P4” referencing the NSU Prinz 4. The concept blends historic design cues with modern electric propulsion, representing a symbolic bridge between the site’s industrial heritage and Audi’s electrified future.
DEVELOPMENT & PROJECT BACKGROUND
The EP4 project began in January 2023 as a trainee initiative involving apprentices from automotive mechatronics, body construction, painting, and vehicle mechanics programs. The group worked under guidance from Audi training staff and received technical support from Audi’s development departments.
The donor vehicle was a 1971 NSU Prinz 4 that had been off the road for decades. Initial work focused on restoring the body structure, including extensive rust repair. From there, the trainees engineered a full electric conversion, integrating high-voltage components, revised chassis systems, and modern performance hardware.
According to Xavier Ros, Member of the Board of Management of Audi AG for Human Resources, projects like the EP4 demonstrate the company’s future strength through its young technical talent.
POWERTRAIN & ELECTRIFICATION
The EP4 replaces the Prinz’s original rear-mounted two-cylinder gasoline engine with a rear-mounted electric motor sourced from a 2020 Audi e-tron. The motor produces 176 kW (240 hp), representing a dramatic increase over the original output of approximately 22 kW (30 hp).
Energy is supplied by a high-voltage battery adapted from the plug-in hybrid Audi Q7 TFSI e quattro. The battery pack is positioned at the front of the vehicle, where the Prinz originally housed its fuel tank, creating a front-rear mass distribution distinct from the original layout.
Cooling air is directed through a large lower front intake, while heat exits through an opening in the hood. Additional cooling is aided by a tailgate that can be fixed in a partially open position, visually exposing the electric drivetrain in a nod to historic NSU racing variants that displayed exposed intake components.
CHASSIS, BODY & AERODYNAMICS
To accommodate the increased performance, the EP4 uses a modified floor structure from an Audi A1, including its axles and braking system. The classic Prinz body was significantly widened and reinforced before being mounted onto the updated chassis.
Pronounced fender flares house wide modern performance tires. These flares were designed in collaboration with Audi Design and produced using 3D printing technology. Carbon fiber was used for the front hood, reducing weight and adding structural rigidity.
A prominent rear wing finished in Signal Yellow is mounted directly to the interior roll cage rather than the body. Its supports pass through the rear window, making the aerodynamic element a visible structural component.
EXTERIOR DESIGN
While heavily modified, the EP4 retains key visual elements of the original NSU Prinz 4, including its characteristic shoulder line, roof profile, and classic front and rear lighting. The body was refinished in Audi Suzuka Gray and Brilliant Black, with anniversary “150” graphics applied to reference the Neckarsulm site’s milestone.
The blend of historic proportions with exaggerated motorsport-style bodywork reflects the concept’s dual focus on heritage and high performance.
INTERIOR & DRIVER INTERFACE
The interior adopts a minimalist, race-inspired layout. A Signal Yellow roll cage contrasts with predominantly black interior surfaces. Seating consists of Recaro Podium bucket seats, emphasizing the car’s performance orientation.
Instrumentation and vehicle diagnostics are handled by a single-board computer connected to a display that functions as a digital instrument cluster, speedometer, and system monitor.
SIGNIFICANCE
The Audi EP4 Concept represents both a technical learning platform and a symbolic statement about Audi’s future direction. It highlights the integration of classic vehicle heritage with modern electric mobility while showcasing the skills of Audi’s next generation of technical specialists.
By combining advanced manufacturing methods such as 3D printing with high-voltage electric drivetrain technology, the EP4 embodies Audi’s broader transition toward electrification while honoring the historical legacy of the Neckarsulm site and the former NSU brand.
REFERENCES
Audi AG press release, “EP4: NSU Prinz 4 with e-tron Power, Trainee Project at Audi Neckarsulm,” July 10, 2023
Audi historical archives, Neckarsulm site history
Wikipedia contributors, NSU Prinz
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