During the World Human Powered Speed Challenge, vehicle designer and manufacturer Aerovelo broke its own record for the fastest human-powered vehicle ever, going 89.6 mph in an egg-shaped bike known as “Eta.” The bike has an empty weight of 55 pounds, and according to Aerovelo, its carbon fiber outer shell is designed to cut down drag by more than 100 times better than the most streamlined cars.

The shell was constructed with prepreg carbon fiber-honeycomb sandwich materials, and the frame was laid up with wet carbon fiber.

Aerovelo says analysis of the vehicle’s performance showed that Eta requires less than 198 watts of pedal power at 90 km/h (60 mph), which translates to 9,544-mpg highway fuel efficiency. That is believed to be the highest per-passenger mpg of any existing transportation technology at that speed.

“The efficiency of this vehicle seems impossibly high: it’s a powerful example of the massive change we can achieve with existing technology in the near future,” said Aerovelo co-founder Cameron Robertson. “Eta’s performance is a testament to the passion and engineering the team devoted to this endeavor, and showcases what can be achieved when we seek to do more with less.”

Aerovelo’s other co-founder, Todd Reichert, says the Eta rides very smoothly.

“It’s an unbelievable feeling to be riding in something that efficient,” says Reichert. “It cuts through the air with such little resistance, and before you know it, you’re cruising at highway speeds on nothing more than your own power. When you realize that this is the same amount of power it takes to light up a few light bulbs, it’s truly mind-blowing.”