Welcome to the PAC-Car II website!

Powertrain and Control

Guinness World Record

PAC-Car II holds the current World Record in fuel efficiency!

Watt d'Or

The PAC-Car II Team won "The Watt d'Or 2007" Award for energy efficient mobility, by the Swiss Federal Office of Energy >>!

Energy Globe Award

PAC-Car II won the Energy Globe Award 2005, catergory "youth" >>!

PAC-Car II - The Book

The book about PAC-Car II is available now >>

Shape of PAC-Car II

The shape of PAC-Car II is now available as CAD Data >>

Would you like to learn more about modeling and optimization of advanced vehicle propulsion systems? Click here!



The whole fuel cell system (including control and power electronics) has been designed at the ETH Zurich.

The fuel cell, a by-product of the PowerPac project, is of the PEM type (Proton Exchange Membrane) and benefits from an embedded auto humidifying area specially designed by PSI. The stack efficiency is exceptional, close to 70%.

All the fuel cell system auxiliaries have been chosen for their reliability, light weight and energy efficiency.


In accordance with the race regulations, some auxiliaries are powered by battery.


Control of the whole system is managed by a microcontroller main board.


The 2 driving motors are the CC type and come from standard Maxon motors which have been significantly improved with a view to adapting them to the specification and increasing their efficiency.

The transmission uses a gear pair. Its speed ratio depends on the track and on the target average speed. It can be "open" to reduce the drag torque, for instance when the vehicle is gliding downhill.


The use of the powertrain is optimized by working backwards from a model based on measured efficiency maps of the fuel cell system and the motors, and on the track topography. The approach used requires simulation tools developed on Matlab Simulink.


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© 2015 ETH Zurich | Imprint | Disclaimer | 28 September 2005