In 1973, Plymouth was at its peak in sales and production. Unfortunately, it was mainly downhill from there.

When the Chrysler Corporation launched the Plymouth division on June 7, 1928, Walter P. Chrysler and his crew pulled off a Motor City miracle. In just four years they hauled the new brand to third place in the brutally competitive low-price field, blowing past everyone except Ford and Chevrolet, the industry giants. Plymouth would then hang onto that spot for decades, falling back at times but then reclaiming it in 1970-71. And while Plymouth slipped to fifth in the 1973 model year, it scored its highest volume in the brand’s history at 882,196 vehicles—a figure it would never match in its next 29 years.

(Note: A carmaker’s annual output can be reported many ways, including model year production, calendar year production, model and calendar year sales, and so on. Meanwhile, these figures are often misstated or confused. Some sources quote Plymouth’s ’73 model year production at 746,821 units, another at 973,000, while we believe the 882K number is more accurate. But either way, the premise here stands: In MY 1973, Plymouth was at/near its peak in sales and production.) 

By far the division’s volume leader was the compact Valiant at more than 380,000 vehicles, accounting for 43 percent of Plymouth’s sales in  ’73. Meanwhile, the sporty two-door Duster fastback was the most popular body style, outselling the boxy coupe and sedan by more than 2:1. Buyers could opt for the basic Duster coupe with Slant 6 power at only $2,376, or step up to the Duster 340, a junior muscle car that boasted a 240 hp V8, heavy-duty suspension, special graphics, and other goodies.

Plymouth’s intermediate-class Satellite remained a steady mover, racking up nearly a quarter of the ’73 sales. The Road Runner (lead and bottom photos) was still in the lineup with as much style as ever but a limited choice of powertrains. A 318 CID V8 was standard, while the optional 400 CID big-block V8 was choked down to 280 hp by emissions requirements and offered only with the Torqueflite automatic. The rest of the lineup: Satellite, Satellite Custom, Satellite Sebring, and Satellite Sebring-Plus. The stylish two-door coupes outsold the sedans and wagons by a wide margin.

By 1973 the Barracuda, Plymouth’s once-popular entry in the ponycar field, was nearing the end of the road. The Slant 6 and big-block V8s were gone and now the engines were limited to the standard 318 CID V8 and optional 340 CID V8. When the new Dodge Challenger was introduced alongside the redesigned Barracuda for 1970, Chrysler’s pony car sales were essentially split down the middle. Barracuda volume actually increased more than 20 percent in ’73 to better than 22,000, but both Chrysler ponycars were discontinued after 1974.

Next to the Valiant/Duster, the full-size Fury was Plymouth’s volume leader in ’73 at more than 261,000 units. The lineup consisted of Fury I, Fury II, Fury III, and Gran Fury. While the decently equipped Fury III was the best seller, the flagship Gran Fury offered an upgraded interior and additional exterior chrome for a few hundred bucks more. For ’75, the intermediate-class (B-body) offering was renamed Fury and the full-sized (C-body) Fury became the Gran Fury.

While 1973 represents a high point for Plymouth, it also marks the beginning of the brand’s steady decline. In 1975, Plymouth volume fell below 500,000 for the first time since 1963, and with the corporation’s total market share slipping, it became harder to justify development and marketing budgets for the individual brands.

When the 1978 Plymouth Volare was rolled out, it was a virtual clone of the Dodge Aspen. And while the 1981 K-cars—Plymouth Reliant K and Dodge Aries K–are credited with saving the company, the two versions were virtually indistinguishable. The launch of the Eagle brand in 1988, triggered by Chrysler’s acquisition of American Motors. diluted the lineup even more

With the benefit of hindsight, the writing was on the wall in 1979 when, for the first time, Dodge sales surpassed those of Plymouth, the corporation’s supposed volume leader. Chrysler’s marketing message presented Plymouth as its entry-level brand, but the narrow model range, essentially clones of other Chrysler models, limited sales. By 1995, there were just three domestic models in the Plymouth lineup: Voyager minivan, Breeze, and Neon. The last car to wear a Plymouth emblem, a Bright Silver Neon sedan, rolled off the line at the Belvidere, Illinois assembly plant on June 28, 2001