In the annals of automotive history, there are plenty of unique and groundbreaking innovations that have changed the way we drive. Some of these inventions have become iconic, while others have faded into obscurity. One such experiment that you might not have heard about is General Motors’ venture into coal-powered turbine engine cars. It’s a fascinating story that few remember but certainly deserves a closer look.

The coal-powered turbine engine car was born out of the energy crisis that rocked the world in the 1970s. With oil prices skyrocketing due to political instability in the Middle East, automobile manufacturers worldwide were scrambling to find alternative sources of power for their vehicles. General Motors, one of the largest and most innovative automakers at that time, turned to an unexpected source – coal.

Coal, a fossil fuel with a long history of use in industrial applications, was abundant and relatively cheap to extract. Recognizing this potential goldmine, GM set out on developing their coal-powered car, which they dubbed as the “Coal Test Unit.” The aim was simple: burn pulverized coal directly in a gas-turbine engine capable of delivering sufficient power to drive a car.

Under the project’s leadership of Richard Gerstenberg (who later became Chairman at GM), engineers began working on transforming this ambitious idea into reality. The team first retrofitted an Oldsmobile Toronado with their experimental turbine engine and replaced the standard gasoline fuel supply with powdered coal.

The results were promising. During early testing phases, engineers found that they could deliver up to 100 miles per 22 pounds of powdered coal while maintaining adequate power output from the turbine engine. The test vehicle was even reported to hit speeds well over 100 mph.

However, it wasn’t all smooth sailing for GM’s coal-turbine project. Handling pulverized coal posed several challenges for both handling and storage. Pulverized coal has a high risk of spontaneous combustion, which can be extremely dangerous in an automotive context. Furthermore, the turbine engine required extensive filtration to prevent solid particles from damaging the delicate internal components.

Environmental concerns were also a pressing issue. Emissions from the coal-turbine engine were far higher than those of conventional gasoline engines at that time. Despite these challenges, GM remained optimistic about their new turbine technology and its potential for reducing reliance on foreign oil.

Unfortunately, the Coal Test Unit never made it past the prototype stage. Interest in alternative fuel sources waned as oil prices stabilized in the 1980s and resources were allocated elsewhere within the company.

Today, General Motors’ coal-powered turbine engine car remains a curious footnote in automotive history – an example of bold experimentation during tumultuous times. While it may not have revolutionized the way we drive, this unique project serves as a testament to the ingenuity and resilience of auto engineers when faced with challenging situations.