Vintage Review: 1974 Peugeot 504D – Doctor Diesel’s Pug Patient


Although Mercedes-Benz was a pioneer and world leader in automotive diesels, starting with their 260D in 1936, Peugeot was also an early advocate of diesel power and sold a good number of diesel-powered cars around the world. So was the Peugeot diesel an unsung hero?  How competitive was Peugeot’s oil-burner as the U.S. diesel craze exploded in the wake of the Arab Oil Embargo?  Let’s go back to 1974 and have a look at Road Test Magazine’s reviews, covering both the initial drive test as well as a 50,000 mile teardown report for a Peugeot 504D.




(Editor’s note: Road Test is mistaken in saying that Peugeot has been building diesel cars longer than any company, including Mercedes. Peugeot’s 1923 diesel car was strictly a prototype, using a proprietary engine to test the concept, and never went into production. A number of manufacturers did the same thing at the time, to see if a diesel passenger car was viable. They weren’t, because the diesels of the time were too large, heavy, noisy, rough-running and lacking in power. They were just barely suitable for trucks.

Mercedes pioneered the passenger car diesel, its 260D, in 1936, and although it was an improvement, it was used strictly for taxi and commercial use. As were almost all Mercedes diesels in Germany, except for farmers and some other hard-core types until it very slowly won acceptance among regular buyers in the 60s. The energy crisis began to make it more popular, just like in the US. Mercedes built diesels continuously since the 260D.

Peugeot’s first production diesel arrived in the fall of 1958, and used only in commercial chassis the first year. The 1960 Peugeot 403 was the first year it was available in the sedan.

I cannot verify the claim that Peugeot made more diesels through the mid 1970s. I’m a bit dubious, especially since the other claim is clearly wrong.  PN)




Much like its gasoline-powered sibling, the 504 Diesel was filled with quirks.  Of course, all the eccentric “uniquely French” controls carried over, while the diesel added a few more peculiarities like a throttle control that responded best when applied gradually and matched with engine speed.  For American drivers, accustomed to “flooring it” when they were looking to go faster, this was a strange trait indeed.


More odd charts from Road Test Magazine.  The middle chart expressing the “Graph of Recorded Data” is utterly useless.  The Mercedes 240D is the “worst car to date” and Saab Sonnet III is the “best car to date”?  From what time period?  Against which competitors and criteria?  And what on earth did they mean by “Tire Reserve”?  At least I’m clear on the acceleration data: without a doubt, the 504D was bog slow, though in line with other diesel powered cars of the era.




The article headline implies that the 504D was subjected to a grueling 50,000 mile test of its durability in everyday use.  In reality, Road Test Magazine staffers only drove the car for less than half of the total 50,000 mile test.  The bulk of the mileage (around 30,000) was added under controlled conditions by Uniroyal at their test facility in Laredo, Texas.  So not quite “real world”…







So far, it would seem that the Peugeot 504D held up remarkably well as mileage accumulated, with next to no wear.  Some of that could undoubtedly be attributed to the controlled conditions of the Uniroyal test, but still, 50,000 miles was a long haul for a car back in the 1970s when life spans and longevity where typically shorter.  Impressive, right?

Well, it turns out that the oil was changed every 1,500 miles!  No owner on the planet would ever adhere to such a short interval between oil changes–amounting to around a mere 5 or 6 weeks of normal driving between services.  Hell, even the much-maligned Oldsmobile 350 diesel V8 would have seemed pristine under the same conditions…


Ah ha, there’s the dirty secret!  The Peugeot diesel really did need oil changes at no more than 1,700 miles or so.  Otherwise, the oil became “unserviceable,” based on lab analysis conducted by the company in North America.  How many of the 504Ds actually got that kind of tender, loving care?  Easy answer: when was the last time you saw one?



The 504 series was a well-engineered European car, and the diesel, properly maintained (quite a lot of hassle with 1,500 mile service intervals!), probably could have provided years of excellent service, much like a Mercedes-Benz 240D.  The problem was that extra-conscientous, super-thrifty, Euro-centric buyers were few and far between in America in the 1970s.  Plus, without the snobbish allure of the 3-pointed star, the Peugeot had to rely on its product attributes and “character” alone.  And we all know how that turned out…