Tiny cars made out of peppers, onions, grapes, corncobs, and more raced on the roof of the Seamans Center on Monday morning.

First-year engineering students at the UI gathered at the “Vegetable Car Derby” to race custom-designed vehicles made exclusively from fruits and vegetables as part of their course Engineering Problem Solving 1.

Roughly 100 students, divided into groups of four, designed and developed cars capable of moving down an incline using only ingredients from vegetation.

Participants shivered from the cold wind racing over the rooftop and across their faces as they lined up to introduce their entries and explain their design process.

Among the dozen cars, the Potato Prius and the Squash Speedster looked more like hybrids than hot rods. The Prius featured a potato body and used tiny pumpkins for wheels, and the speedster had limes attached to its squash frame.

Luke VanFosson, a freshman majoring in engineering and music, and his group decided to design his car with three wheels instead of four.

“I’m afraid the onion-wheeled vehicles will beat us,” he said, watching some competitors launch their car down the ramp.

Biomedical engineering Associate Professor Madhavan Raghavan agreed with VanFosson’s assessment that onions seemed to make the best wheels.

Combatants were instructed to consider friction, weight, stability, and aerodynamics while constructing their entries, whose dimensions were no greater than 1 foot.

“The goal is exposure to hands on engineering,” Raghavan said. “We want to make it fun for them.”

The competition began with two timed solo-runs down the plywood track. Some of the vehicles veered off to one side and into or over makeshift guardrails as they raced toward the finish line.

The students prepared for the second round of timed runs after making some quick repairs to their roadsters. When the timed runs completed, three cars stood out as the fastest of the bunch, which were then thrust into a head-to-head single elimination tournament.

In the end, the onion-wheeled veggie stew speedster, designed by UI engineering students Serghei Dacin, Anil Mishra, Andrew Manning, Erin Maze, and Liaochao Song, emerged victorious.