Iron Warriors: Polish Students' Car Covers 837 km on One Litre

A student team from Lodz University of Technology has built two vehicles that stretch a single unit of energy further than most people would believe possible. The petrol prototype covered 837 km on one litre of fuel, while the electric one achieved the equivalent of 2,267 km per litre of petrol.

The results come from the Iron Warriors, part of the university's Student Scientific Circle of Automotive Enthusiasts. For nearly 15 years the group has designed and built vehicles whose only goal is to travel the longest possible distance on the least energy. The students have set Polish records in fuel-economy competitions twice.

The figures are not everyday driving results. They were achieved in specialised contests for energy-efficient prototypes.

Light, slim and shaped like a drop

The key is low weight. Both vehicles have three wheels and streamlined bodies, and each carries a single driver in a reclining position. The carbon-fibre shells keep the weight of each vehicle below 50 kilograms, so far less energy is needed to get them moving and keep them going.

Aerodynamics matters just as much. The designers gave the vehicles a teardrop shape to cut air resistance, which becomes a dominant factor in energy use at higher speeds.

The team currently develops two designs: Eco Arrow 3 and Eco Arrow 2 Electric. The first uses a modified engine originally made for a petrol brush cutter, while the second runs on an electric motor of the kind used in bicycles.

What comes next

Data gathered during runs helps the students analyse the vehicles and refine them. Driving technique matters as much as the construction itself. Team leader Hubert Pacyna says the young engineers keep improving both vehicles to beat earlier results.

The group is now working on another prototype, focusing on aerodynamics and a new body designed to cut motion resistance further. The vehicles will not be used on public roads, but the lessons carry over: reducing mass, improving aerodynamics, lowering rolling resistance and optimising drivetrains are problems that major carmakers also work on.