Muscle cars had hit the mainstream by the end of the 1960s, which meant rising costs for enthusiasts across the board as automakers did their best to cash in on the desire for big engines in moderately-sized coupes and convertibles. Recognizing that not every customer out there had the budget for both luxury and speed at the same time, Chrysler forged ahead with a low-buck version of its popular high performance formula, creating a golden era muscle car legend almost by accident.
The Plymouth Road Runner was more than just a clever marketing concept—it was an exceptional effort that cut straight through to the heart of buyers who dreamed of a big block V8 fix, and a pure driving package that quickly expanded well beyond its intended audience of frugal speed fans.
Go Cheap Or Go Home
Plymouth had two important things going for it when assembling its affordable muscle car for the 1968 model year: the lightweight and stylish Belvedere B-body platform, and a trio of big block V8 engines that fit easily between its front fenders.
The Belvedere's stripped-down ethos was a perfect fit for the price point Plymouth was after with the Road Runner. The car came with bench seats, manual steering, four-wheel drum brakes, and even vinyl floor coverings in place of carpet. It was possible to add a few niceties back into the mix when ordering a Road Runner, but the majority of comfort features were reserved for the Plymouth GTX, the highest-spec version of the B-body based on the more sumptuous Sport Satellite.
All versions of the Road Runner started out with a 383 cubic inch, 335 hp eight-cylinder engine, which borrowed a long list of features (including heads, camshaft, and exhaust manifolds) from its larger 440 cubic inch cousin. Its 425 lb-ft of torque were managed by a four-speed automatic transmission (with a 727 Torqueflite automatic three-speed optional), sent back to a standard 3:23 rear gear ratio, and the vehicle's spring rate was also stiffened to improve road-holding.
For an additional $714, the 383 could be replaced by the vaunted 426 cubic inch Hemi, which delivered 425 hp. That was not an insubstantial sum in '68, but given that the Road Runner started at a little more than a $1,000 less than the GTX, it was a fantastic value for those who cared exclusively about speed.
Branding, too, was front-and-center with Plymouth's Road Runner effort, as the company spent $50k to license the face of the famous cartoon character and its 'beep-beep' for the horn (as well as the image of its nemesis, Wile E. Coyote). No other muscle car at the time could boast the same kind of pop culture tie-in, and the Road Runner blazed a path that was soon followed by models like Pontiac's GTO 'The Judge.'
Dominant On The Streets, And The Sales Sheets
Plymouth was astounded by the Road Runner's popularity. In the first year alone, close to 45,000 units were sold, which was multiples of what Mopar executives had expected from a project they had fought against for years, assuming that a barebones performance car would steal profits from vehicles like the GTX. The coupe had the opposite effect, focusing a spotlight on Plymouth's entire muscle portfolio and giving the brand a huge boost in the public eye.
The first-generation Road Runner stayed in production through 1970, gaining the option of a 440 cubic inch 'six pack' triple-carb engine mid-way through '69 (390 hp, 490 lb-ft of torque), a convertible body style, and an aggressive air-grabber hood. 1970 models featured a more comprehensive front-end re-styling, and also spawned the NASCAR-oriented Superbird, with its massive rear wing and extended aero nose cone.
Plymouth almost doubled sales following the car's debut before coming back down to earth in its final year, impacted by the glut of muscle machines that had followed in the Road Runner's footsteps as well as rising insurance costs for the powerful street warriors.
A Slow Decline
For 1971, Plymouth made major changes to the Road Runner formula. The new B-body shape was shared with Dodge Charger, cutting down on the coupe's distinctiveness on the market. The more rounded design also began to add features not previously found in the simpler, original Road Runner, and output from both the 383 (300 hp) and 440 (385 hp) dropped somewhat. The Hemi stayed in the picture, and was joined by the 275 hp, 340 cubic inch small block that had been a mainstay of Chrysler's smaller cars the year before.
Wider and longer, the '71 Road Runner offered improved handling for those eager to throw their muscle car through the corners, but buyers stayed away in droves, dropping sales to just a tick over 14,000. The following year, the same EPA restrictions that snaked their way through the entire auto industry began to negatively impact the Road Runner, wiping Hemi from the mix and throttling the remaining engines with wilting 'net' power ratings imposed by SAE standards.
It was a trend that continued throughout the second-generation Road Runner's brief lifespan. By 1973 the car had been given a more squared-off restyling that did little to halt its sales slide, one made worse by the elimination of any big block engine options other than a neutered, 280 hp version of the 440.
After moving through a series of lukewarm small block V8s, the Road Runner retired from its role as a just-the-basics muscle car by 1975, transitioning into a plush trim level on a several Chrysler coupes that lasted until the end of the decade.
Although its final years might have been more flash than actual substance, the Road Runner played a key role in opening up the muscle car market. Without Plymouth's cost-conscious gamble, we might never have seen equally affordable choices like the Plymouth Duster, the Dodge Demon, the Chevrolet Nova, or the Oldsmobile Rallye 350, or over-the-top examples of racing homologation like the Plymouth Superbird. The Road Runner remains a shining example of late-60s innovation framed by a cloud of tire smoke.