Besides being a comedian and talk show host, Jay Leno is known for his impressive collection of unique and classic cars. He owns hundreds of them literally, and his collection is always in flux with new additions and replacements. One section of his collection includes steam cars, which are vehicles powered by steam and not internal combustion engines like most cars. These steam cars don’t skimp on performance either.

Jay Leno’s impressive car collection

According to DuPont Registry Daily, out of his great garage full of his private collection, Leno has about 340 vehicles total. His entire collection of about 160 motorcycles and 181 cars is worth over a whopping $52 million. 

Leno owns all different kinds of cars from a range of years going back to the early 20th century and the dawn of the automobile. This includes electric cars of the past, trucks, race cars, supercars, muscle cars, turbine cars, and steam cars, to name some types.

There are unique cars like his 1969 Lamborghini Miura S, arguably the first supercar, and renowned classics like his 1954 Jaguar XK120M Coupe, Business Insider reports. His 1925 Doble E-20 Steam Car, once owned by business mogul Howard Hughes, is fascinating for car enthusiasts and novices alike.

The Doble steam car engine

Leno lauds the Doble steam engine as the greatest ever built, according to Jay Leno’s Garage. On the show, Leno seeks to share information on his cars in a way that is accessible and understandable to most people. The use of a steam engine in an automobile is just as fascinating as it sounds.

Leno touts his Doble E-20 Steam Car and all Dobles as the best in large part to the relative ease of operating them, especially in comparison to other steam cars. With the Doble, the driver can turn the key and go after some preparation. Previously, the driver had to light a pilot for the engine by hand using a match or a torch for other steam cars, wait about 15 minutes for the systems to heat, and complete other tasks before setting out.

Best of all, just because it’s a steam engine does not mean the Doble lacks performance. Howard Hughes reportedly got the Doble to a speed of 132.5 mph in 1925, Leno recounts.

The Doble’s history and specifications

When the assembly line was revolutionizing building cars, drastically cutting previous production time, the Doble was built by hand. Because of this, no two Dobles are built the same. Leno attributes the changes to the fact that it would take time to put the car together, and by the end of it, there would be improvements implemented into the next unit.

As Barron recounts, steam cars were more popular in the U.S. because heavy taxes were levied on them in England. In the early 1900s, when there were only about 8,000 cars on the road, steam cars had a large share of those.

Early gas-powered cars were loud and scary to be around, startling people and horses nearby. Steam cars had the advantage of being quiet, Leno says. The Doble was a sleek and modern-looking convertible as well, with a disappearing top that would get packed away into the body and a popular rumble seat in the back to seat two more passengers. It has a large 142-inch wheelbase and weighs over 5,000 pounds.

According to History Net, Abner Doble, an MIT-educated engineer born in California, came up with the Doble. The Doble mechanically beat the popular Ford Model T and could travel farther using a 17-gallon tank of water and 26 gallons of kerosene to power the steam engine. The Model T, by contrast, had an internal combustion engine that could only hold 10 gallons of gas and took 40 seconds to reach a top speed of 40 mph. The Doble could go up to 60 mph in 10 seconds. 

To reach those speeds, the Doble produces 125 hp along with a huge 1,000 lb-ft of torque. It had fewer moving parts in the engine compared to other steam car brands like Stanley. What’s more, there’s no transmission in the Doble, so there are no gears to shift. The car is direct drive, which means that the torque is what keeps it moving. 

Although how the car works is slightly complicated. It boils down to turning on the water pump to build pressure and turning on the burner, which literally boils the water to steam. Once the engine builds enough pressure and temperature, the steam powers the engine, and you’re good to go. The Doble could hold pressure better. Once it reached peak operation, it needed minimal power to keep it driving, unlike other steam cars where the driver needed to pull off the road periodically to allow the engine to build pressure.