These days, every manufacturer is working on ways to boost fuel economy and reduce its carbon footprint. While some are content to downsize engines and rely on forced induction to make up the power, others push the boundaries of technology, developing hydrogen fuel cells, or Diet Coke and Mentos-powered rocket sleds.

While research into Diet-Coke-and-Mentos-powered automobiles is in its infancy, one team of entertainers-turned-mad-scientists has not only developed a diet soda and candy rocket car, they’ve actually taken the time to improve the design for greater range from less fuel.

The original Rocket Car Mark 1, developed by Fritz Grobe and Stephen Voltz, required  108 bottles of Diet Coke and 648 Mentos candies to travel a distance of 217 feet.

By simplifying the design, revising the rocket engines and “adding lightness,” as Colin Chapman would advise, CBS Connecticut reports that the pair’s Rocket Car Mark 2 was able to cover 239 feet on just 54 bottles of Diet Coke and 324 Mentos candies.

While an improvement, we’re still years away from a practical implementation of junk food engines in production cars. Traveling the distance equivalent to the Chevy Volt’s 35 mile battery-only range would require nearly 42,000 bottles of Diet Coke and over a quarter-million Mentos candies, making such a vehicle cost-prohibitive to operate.

Besides, who wants to stop for a ten-minute refueling operation every 239 feet?