This Company Is Developing a New Air-Cooled Flat-Eight Engine. It Sounds Amazing

This air-cooled 5.3-liter flat-eight engine is perfect for old Porsche 911s.

Photo by: Runge Cars

By: Anthony Alaniz

Oct 17, 2025 at 11:59am ET

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If we're to believe recent news, internal combustion engines aren’t going anywhere. Despite all the doom and gloom, consumers still prefer gasoline-powered cars, and enthusiasts will soon have a new one to potentially add to their next project. It comes from Runge Cars, and it’s not for your everyday project car—it’s an air-cooled 5.3-liter flat-eight.

It’s called the Hetzer, and it’s a four-cam, 32-valve engine that will power Runge’s new R3, a chassis and body design from the Minnesota outfit. The R3, which the company says is "purpose-built to deliver the most visceral, analog driving experience available today,” pairs the new engine with a six-speed manual transmission.

The car itself weighs 1,720 pounds and took seven years to develop.

“The engine is more than a machine—it’s a statement,” said company founder Christopher Runge. “It’s an engine that not only pushes the boundaries but fits seamlessly into the legacy of air-cooled performance.

Photo by: Runge Cars

Runge worked with Swindon Powertrain, a 50-plus-year-old company that manufactures bespoke powertrains and engine components, and air-cooled specialist Sol Snyderman on designing the flat-eight.
The company didn't provide any performance specs, but it will have a 9,000 rpm redline and will have “direct bolt-in computability” with air-cooled Porsche 911 platforms.

The first three engines will be Runge-exclusive commissions. Runge will begin taking customer orders for the engine and R3 later this year. We’ll get pricing, the full specs, and the performance numbers “in the coming months."

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The Internal Combustion Engine Won’t Die

Despite regulatory pressure, American consumers aren’t flocking to electric vehicles as expected, forcing automakers to continue to invest in combustion engines. Ferrari’s chief research and development officer recently said engines haven’t peaked yet. The company recently said it would continue investing in them, including the V-12.

BMW, Mercedes-Benz, and Porsche have also said they’re committed to combustion engines for the foreseeable future. Gas engines just won’t die, and we continue to get great aftermarket products that should keep them alive even longer.