Detroit’s Big Three automakers have a long history of intense competition, and one of the most heated periods in this decades long rivalry was the muscle car era of the 1960s and 70s. Legend after automotive legend was born in this short time. Names like Mustang, Camaro, and Challenger not only broke through to the mainstream, but they have also persisted into the modern day. And yet, for the motorhead faithful, the list of muscle car icons runs long. The Chevy Chevelle and the Plymouth Roadrunner undoubtedly make the list.
The Chevrolet Chevelle had already seen a full generation before the Plymouth Roadrunner first debuted. Conveniently for the purposes of this comparison, both the second generation Chevelle and the first-generation Roadrunner arrived in 1968.
The Chevy Chevelle was based on GM’s A-frame, shared with the Chevy Monte Carlo, Buick Skylark, Oldsmobile Cutlass, Pontiac Tempest, and many other cars. As such, the Chevelle’s mid-size architecture allowed for a number of body styles from two-door coupes to four-door station wagons. Most significant among the Chevelle’s was the SS (Super Sport) which had its origins a generation prior with the Malibu SS trim.
The 1968 model year’s updates to the Chevelle were thoroughgoing, including a shortened wheelbase. But most significantly, the new body leaned hard into the now classic “long hood/short deck” muscle car design. In ’68, the Chevelle offered three different version of the 396 big block V8 good for 325hp, 350hp, or 375 hp. The following year, the SS 396 package made that trio of V8s available across all Chevelle variants.
The Plymouth Roadrunner debuted in 1968, sharing its B-body platform with Plymouth Belvedere (on which the Roadrunner was based) and Plymouth Satellite. GM paid a $50,000 licensing fee to Warner Brothers for the rights to use the Roadrunner name and cartoon character on their cars. The Roadrunner’s formula of affordable muscle proved wildly popular. Sales for the Roadrunner more than doubled the expected number of 20,000 units sold. Following the Roadrunner’s initial success, Dodge decided it too wanted to make their own B-body muscle car, which ended up being the Dodge Super Bee compete with a cartoon bee emblem.
For both 1968 and ‘69, the Roadrunner came with two V8 engine options: a 383 cu.-in. making 335 hp or the 426 Hemi making 425hp. Transmission included a standard four-speed manual or three-speed TorqueFlite automatic. In 1969, Plymouth added bucket seats, an optional floor shifting automatic, and a convertible option. This was also the year of the A12, a Roadrunner variant featuring a 7.2L V8 with Holley carburetors and a 390hp. Sales improved still further, nearly doubling yet again to over 84,000 units sold.
At this point, the Roadrunner’s surprise sales success puts it off to an early lead over the formidable Chevelle.
While the Mustang and Camaro, in all their chrome glory, deservedly received the adoration of horsepower fanatics, the Chevelle and Roadrunner were smashing both sales estimates and quarter mile times. And, as 1970 rolled around, the two cars were poised for a showdown with the introduction of the 454 big block to the Chevelle. Chevy was indeed breaking out the big guns in the muscle car wars.
The LS6 454 V8 made a thundering 450 horsepower and 500 lb.-ft. of torque. The 454 SS Chevelle could rocket from zero to 60 in six second and achieve a top speed of 142 mph, making it the fastest muscle car you could buy in 1970. Of all the Chevelles, the 454 SS remains the pinnacle of the nameplate.
And yet the LS6 454 wasn’t enough for Don Yenko of Yenko Chevrolet in Canonsburg, PA. Yenko had discovered a novel hack in Chevy’s ordering system. Though it wasn’t in the brochures, Yenko would submit orders via the Central Office Production Order (COPO) system by which he could procure Chevy muscle cars with non-stock motors. Such “Yenko Super Cars” included Novas, Camaros, and 99 Chevelle Yenko S/Cs featuring a Holly carbureted 427 V8 under the hood.
The Roadrunner’s 426 Hemi was still good enough for second place on the street in 1970. And all glory wasn’t lost for Plymouth, either. The success of the Dodge Charger Daytona on the 1969 NASCAR circuit led to Richard Petty, then driving for the Plymouth team, to ask Chrysler for the Daytona’s advanced aero bits for his car. When Dodge demurred, Petty jumped ship for Ford. In an effort to lured Petty back, the Roadrunner was given the Dayton’s aero, complete with nose cone and gigantic rear wing to create the Superbird. The 1970 Roadrunner and other “aero cars” were so successful that NASCAR ended up changing the rules effectively ban them. Today, Petty’s blue 1970 Superbird is among the most iconic of all NASCARs of all time.
As with many of the era’s muscle cars, fuel and emissions regulations arrived to spoil the party for the Chevelle. The SS’s engine was downgraded to a more economical small block and the LS6 454 dropped entirely. There were other minor changes that included the introduction of a “Heavy Chevy” trim which allowed buyers to get a V8 even in the base Chevelle. In 1972, a year out from an upcoming generational update, the Chevelle remained largely unchanged from the prior year. The Chevelle would get a new generation starting in 1973 and running through 1977. The heady days of the muscle car were already gone. Sure, you could get a Chevelle Malibu SS station wagon, but a killer power wagon the likes of today’s Mercedes-Benz E 63 S it was not.
The Plymouth Roadrunner embarked on a new generation in 1971 with revised styling and improved interiors. Features like pile carpeting and power leather seats meant the once budget-minded Plymouth was getting more refined inside. Like the Chevelle, the Roadrunner saw few changes in 1972 aside from diminishing engine options and the discontinuation of the 426 Hemi V8, likewise due to emissions regulations. The ’73 and ’74 models received significant styling updates that help buoy sales but the writing was on the wall. The days of the Roadrunner as a muscle car mainstay were numbered. Meanwhile, despite the lost aero, Richard Petty and the Roadrunner continued to dominate the NASCAR circuit in the early 1970s.
So, which was the better, cooler, faster muscle car, the Chevelle or the Roadrunner? The answer probably comes down to how you weigh that crucial 1970 model year. The LS6 454 equipped Chevelle is rightly a legend of the muscle car age. When ripping burnouts and straight-line speed defined the bleeding edge of automotive culture, the Chevelle was literally as good as it got in 1970.
And yet… the $50,000 Chrysler paid for the Roadrunner rights prove the power of cross promotion. The Roadrunner’s identity perfectly dovetailed with that of the car. The Roadrunner character, a mischievously swift bird continually thwarting the persistent yet unlucky coyote, was just the playful yet preternaturally capable emblem that Roadrunner car owners could identify with and seek to emulate. The success of NASCAR legend Richard Petty in Roadrunners further cemented the car in the imaginations of motorheads. In the final analysis, the Chevelle might have had the LS6 454, but it never had a cartoon Roadrunner decal or a horn that literally went “beep, beep.”