Six Decades Ago, Gas Was Too Cheap For Chrysler’s Diesel Taxis To Succeed

The tale of diesel in America has been told many a time. Fuel got crazy expensive in the 1970s, and US automakers responded with diesel engines designed to seriously improve fuel economy. GM got it badly wrong, while other automakers did a little better. Ultimately, diesel trucks started kicking serious butt in the late 1980s, while diesel passenger cars were largely kicked out of the market.

However, that’s really just the mainstream story. Decades before the Malaise Era struck, there were those that saw the potential of diesel for regular road-going vehicles. It promised efficiency a step above that of the contemporary gasoline engine, even if acceleration and usability lagged well behind. The hope was that for a few select customers, diesel power might make sense. A tiny number of diesel conversions came into being, hoping to find customers who appreciated the benefits of compression ignition engines.

If you hunt around today, you might just come across a rare survivor from the early days of Chrysler’s experiments with passenger car diesels. These vehicles weren’t fast, pretty, or influential—and that’s why they’re almost completely forgotten today.

Crazy Taxi

The great minds over at Oppositelock and Barn Finds came across something unique this week—an eBay listing for a 1959 Plymouth Savoy, Georgia license plate GEO 779. That might not sound particularly wild, but this one is special—under the hood lurks a four-cylinder diesel engine. What’s more—it appeared to be completely stock!

The Savoy is up for sale for $10,000, and we’re told it has 59,000 miles on the clock. It’s got a three-speed manual transmission. The interior has been refreshed and restored, though we’re told the heater is currently non-operational and that the heater core has been looped off. But what we really want to know about is what lurks under the hood.

Look at the photos of the car, and you’ll notice a strangely large and complicated badge on the bodywork. That happens to be the logo of Perkins Diesel, the company that manufactured the engine under the hood.

Perkins was an English manufacturer, founded in 1932. By the 1950s, they were turning out thousands of engines every year for a wide variety of applications, from agricultural machinery to power generation and beyond. As it turns out, they also linked up with Chrysler to produce some long-forgotten diesel-powered cars.

This Plymouth is rare, but it’s by no means one of one. In fact, a number of diesel Plymouths were built way back when. If you’ve never heard of these before, though, don’t be surprised. The company’s dalliance with diesel was happening in the mid-1950s, but it was not something it widely shared with the public. The Perkins engine models were largely kept to the European market, though some were marketed for use as taxicabs in the US.

Th engine of choice was the Perkins P4C diesel. This was considered a “high speed” engine because it happened to rev to 3,000 RPM—quite the redline for a mid-century diesel. The 3.2-liter four-cylinder engine had a compression ratio of 16.5 to 1, low by modern standards, and turned out approximately 60 horsepower depending on the exact trim, and around 140 pound-feet of torque. In contrast, a contemporary six-cylinder Plymouth Savoy would have had a 3.8-liter gasoline engine delivering around 130 horsepower and 205 pound-feet of torque. The Perkins engine was no featherweight, either—tipping the scales at 543 pounds. Performance, in turn, was decidedly less than spritely.

As explained by Allpar, Much of the work to integrate these engines into the Plymouth vehicles was done by Hunter NV, a Belgian distributor for Perkins Diesel. The company produced parts to support the diesel conversion—including flywheels and new rear ends to better suit the low-horsepower engines. It also produced conversions for a number of other makes, like DeSoto. Hunter NV worked with Chrysler’s Antwerp assembly plant to produce these vehicles in small numbers. The majority ended up being sold for use as taxis in Belgium. The partnership kicked off in the mid-1950s, surviving until around 1959.

Some of these vehicles eventually ended up coming to the United States and Canada. As covered in Motor Life magazine in 1959, the diesel Plymouths were said to cost “about $750 over the same car equipped with a six-cylinder engine—about $2700 USD.” The conversion came at great expense, but ideally, the improved fuel economy of the diesel engine would pay off in fuel savings. The problem was that the expense was great enough that you had to be doing a lot of miles to make it worthwhile. “While they may be successful in cab operations, where continuous running is a factor, they are unlikely to be worthwhile as a private vehicle,” noted Motor Life. The added cost of diesel installation could not be offset by fuel savings in life of the engine.”

The Plymouth diesel later showed up in Popular Mechanics in the July 1961 issue. Jim Whipple gave a charming review of this then-novel vehicle. He provided a little detail on the vehicle’s origin, a great assessment of the vehicle on its merits, and some context as to how many made it Stateside. His review seems to suggest that at least some of these vehicles were built in the US, not just converted in Europe. In his own words:

It looked like an ordinary Plymouth taxi but it sounded like a flock of woodpeckers trying to make a meal out of a tin roof. You guessed it. That “pocketa-pocketa” noise betrayed the presence of a diesel engine. The bright yellow sedan was one of more than 200 diesel-powered Plymouth cabs hacking around in six U.S. cities.

A look under the hood disclosed a husky four of 204-cubic-inch displacement, rated at 72 horsepower. This power plant, a four cycle job operating on No. 2 fuel oil, was made by Perkins of Peterborough, England, shipped to Detroit, an and placed in the standard 1961 Plymouth chassis. It uses a stock manual transmission.

Driving a Plymouth Diesel is not especially difficult; however, it is different from driving a standard gasoline-powered car. The diesel is started just by turning a key—if the engine is already warm. When starting a cold engine, you must press a switch to energize glow plugs in the combustion chambers, wait a few seconds, and then turn the key. One characteristic of diesel operation, and particularly that of four cylinder engines, is the vibration. Engine mountings take a good deal of it out of the car, so that at cruising speeds from 35 to 55 mph range vibration is noticeable but not objectionable. At low speeds, however, the car throbs somewhat like a cold, wet puppy dog.

Whipple appreciated the low RPM operation of the Perkins diesel, noting you could “really lug this car.” However, he also noted the lack of acceleration, with the vehicle taking 22 seconds to reach 60 mph. Regardless, he noted “our diesel had no trouble in keeping up with the stream of city traffic.” Allegedly, we’re told maximum speed was 75 miles per hour, though 55 to 60 mph was deemed more reasonable.

The magic of the Perkins-engined Plymouth, though, was in fuel economy. Allegedly, a duly equipped cab was driven from Detroit to St. Petersberg in Florida for a cost of just $9.48 in gasoline—roughly $100 in today’s money. We’ve no idea the distance taken, but the car achieved between 28 and 33 mpg according to Whipple. In city use, it performed less well, but still well ahead of a comparable gas engine. Charlie Ross of the Detroit Checker fleet noted his gasoline Plymouths achieved 10 to 12 mpg downtown, versus 19 to 22 mpg for the Perkins diesel.  That allowed the fleet to make back the additional $795 cost of the diesel engine in about nine months on a cab that would rack up about 30,000 miles a year. The article notes, however, that the diesel engine option was only being made available to taxi operators since the economics didn’t really check out for regular drivers who drive far fewer miles in a year.

Beyond this, the trail of the Perkins diesel Plymouths pretty much goes cold. Perkins would continue to work with Chrysler and its affiliated companies in coming years, supplying engines for Dodge trucks and other commercial vehicles. However, the diesel American sedan was dead, and it was not to be seen again for some time.

Survivors

A handful of these vehicles have survived into the 21st century. Back in 2013, Barn Finds covered the case of a 1956 Plymouth with the same good old Perkins powerplant. Meanwhile, in 2020, Bang Shift turned up a Plymouth Belvedere that was apparently from the 1960 model year—making it likely one of the last made. A similar example showed up on Craigslist in Detroit in 2015.

How many of these cars are still around? We don’t exactly know. Popular Mechanics mentioned 200 being built for taxi use in the United States, but numbers on European production by Hunter NV are less clear. Given that taxi fleet production is typically limited, I’d estimate, based on very limited information, that well under 5,000 of these vehicles were ever built.

In any case, the seller of the 1959 Plymouth Savoy  that spawned this article suggests only around 20 survive. In turn, they say they’ve had their car valued and insured for $35,000. For a rare classic that’s not particularly desirable, that sounds about right.

Best of all, though? There’s actually a bit of a modern history on this exact car. That’s because a man named Brian purchased this vehicle all the way back in 2008, and posted on the Forward Look forums about his pride and joy. The vehicle wore the GEO 779 license plate, and had last been tagged in Georgia in 1977. When Brian purchased it in 2008, he stated it was in “solid” shape, having been sold by a son who inherited it from his father’s estate. Brian documented the car’s state quite well, showing that it was rather the worse for wear having sat for so long. He found the VIN indicated that it was built originally as a taxi in Plymouth’s Detroit plant, though he was unable to figure out if it was converted overseas or given the Perkins engine locally.

As per the forum thread, Brian began some preliminary work on cleaning and restoring the vehicle in 2008, before selling it on to a fellow named Ed in 2019. At that time, Ed reported the vehicle “is currently running after lots of work.” Amazingly, the Perkins diesel had held up well despite decades of neglect.

This engine really smoked when it ran for the first time in 40 plus years. It died down a little on it’s own, I guess as the rings reseated and some of the junk blew out. But it still was visible and burned your eyes! Then I started tweaking the fuel injection pump timing and got the smoke down to almost invisible by advancing it a little. Still smells, but not nearly as much.

-Ed

By the end of 2019, the diesel Plymouth was back out and about, getting around to local car shows. His posts wrap up around 2019. It’s not clear whether Ed is the same owner that’s now put the vehicle up for sale on eBay, or whether it’s changed hands in the interim. I’ve reached out to the current seller for more information because it seems like this car has been on one heck of a journey.

It’s funny to think how America got so close to widespread diesel motoring all the way back at the dawn of the Space Age. Ultimately, though, it wasn’t to be. Diesel was really only a military and trucking fuel back then; it wasn’t something you could get at the pump at your local gas station. It also wasn’t particularly appealing, given the high cost of obscure diesel engines. Beyond that, the fuel savings weren’t as relevant in an era when gas was (relatively) cheap. Today, as it did back then, America ignores diesel for the passenger motor car—the power of gasoline remains supreme.

Image credits: Plymouth, Craigslist, eBay