Only a handful of alternatives to the internal combustion engine have been created since the dawn of the automobile, among them a small number of turbine cars. They might become more common, as they are well-suited to supplementing hybrid systems.
Turbine cars powered by simpler machines
Turbines are simpler machines, in principle, than internal combustion engines. Granted, it’s a bit more complicated than the following description, but the gist of how they work is that air is drawn into the engine by a fan and compressed. The air is aspirated with fuel and ignited. The ignition spins another fan at the back of the combustion chamber, sending the exhaust out the back.
In a jet engine, the exhaust is pushed out a greater rate than the air comes in the front, creating thrust. To power a car, the exhaust spins a fan, spinning an output shaft, just like a regular engine does.
The possible benefits of turbine cars are far fewer moving parts and thus greater reliability and longevity, greater power to weight ratio of the motor, and drastically less maintenance. Modern gas turbines can also run on anything that will blow up, including diesel, kerosene or paraffin wax.
Not like they didn’t try
There have been attempts at turbine cars over the years. Various automakers have made earnest attempts for the past 50 years, including General Motors, Fiat and a few others. A few even raced in the Indy 500.
The most famous, of course, was Chrysler, which spent almost 30 years experimenting with turbine cars. In the 1960s, they even released 55 Chrysler turbine cars to the public for trial purposes, almost all of which were returned to Chrysler and destroyed. At least one is still in private hands, specifically those of Jay Leno, according to his column in Popular Mechanics.
However, they had issues. Aside from high cost – the bodies were made by Italian coachbuilder Ghia, according to The Truth About Cars – and only running on kerosene or diesel, there was also significant throttle lag. Just like a turbocharger – which is incidentally a form of turbine – a turbine has to spool up to the appropriate RPM to work, meaning a delay of a second or more after pushing the pedal before the thing accelerated.
Some alternate fuels could be used, though; reportedly the then-president of Mexico got his to run on tequila.
Fuel economy was about 11 miles per gallon, which wasn’t atrocious but still not very good at the time. In short, the Chrysler turbine cars were too expensive, didn’t perform well enough due to lag (though capable of a 12-second 0 to 60 sprint, good for the day) and burned through too much of (then) uncommon fuel, which meant it wouldn’t catch on.
A possible return
However, turbine cars may be about to re-emerge as part of hybrid drivetrains. Since turbines require a constant load to operate, a standard drivetrain doesn’t provide sufficient RPM to operate at all times, hence why they have to spool up like a turbocharger. (Turbines operate at 40,000 to 100,000 RPM; a standard engine runs at 500 to 8,000 RPM.) However, if an engine is acting as a generator, powering a battery system – along with electric motors to drive the wheels – can provide one.
Furthermore, in a hybrid drive system employing regenerative braking and KERS-like energy capture systems, the lag can be offset with captured energy. Further still, since they can run on a number of fuels (including biodiesel, natural gas, paraffin wax), greener fuel usage is possible. Since a microturbine can produce as much horsepower as a standard engine two to three times its size, there’s a lot of potential. As they are simpler machines, they need less maintenance and should last longer.
Hence, a number of car makers have created concepts that employ turbines in precisely this manner, but they are a long way from production. Development costs have proven, thus far, too high to justify production.