Vintage Car Life Review: 1968 Plymouth Road Runner 383 – As Hot As It’s Been Made Out To Be?

 

Any automaker can create performance models by discreetly offering its most powerful engines in the smallest, cheapest cars that will accommodate them, but to put those models (and their maker) on the map, they need a catchy name, an identity, and a marketing concept. For 1968, Plymouth offered a budget-priced stripped-down, souped-up intermediate coupe borrowing its name from a popular Saturday morning cartoon character. Car Life tested the Plymouth Road Runner with the base 383 engine in May 1968 and found it somewhat deficient in both go and stop.

Car Life, May 1968, page 56, first page of Plymouth Road Runner road test with a B&W photo of the car on a mountain road with the headline "Hang the Package, Bring on the Performance" above the text

As most people know, the original Plymouth Road Runner was a stripped-down B-body, essentially a de-trimmed version of the Plymouth Belvedere/Satellite with a big engine and a standard four-speed manual transmission. At the suggestion of Chrysler-Plymouth product planning analyst Gordon Cherry, it was named Road Runner, after the Looney Tunes character, which Chrysler had licensed from Warner Bros. for $50,000. (This is why the name was styled as two words, while the name of the real-life bird is written “roadrunner.”)

 

Car Life seems to have regarded both the source of the name and the accompanying cartoon mascot as beneath their dignity — the text pointedly avoids acknowledging either, and you have to squint a bit to see the Road Runner character decals on the air cleaner lid and rear deck in the B&W photos. The editors explained the car like this:

The Road Runner emulates what a young, performance-minded driver might do on his own, if properly experienced and motivated. Take a basically light, inexpensive, stripped model and load it to the hilt with equipment to make it run and handle. Only instead of the owner’s having to build such a car himself—bit by bit, hit and miss—the factory builds it for him, thus giving added assurances of the job’s being done right, of reliability, of having adequate handling and braking to cope with the engine, of a new-car warranty, and perhaps just as important (though often overlooked), of getting a car whose resale value will hold up much better than something similar done privately.

The latter is a point that enthusiasts who like to modify their cars often seem to miss — and being told that their shade-tree project car is probably going to be tough to sell after they’ve put a lot of money into it makes some people VERY salty (one of the reasons I won’t touch questions about valuation).

 

While the Road Runner was inexpensive, at least to start, the editors’ presumption that it was “basically light” was incorrect. According to the AMA specifications, the base curb weight of a 1968 Road Runner coupe, with four-speed and no power steering, brakes or other accessories, was 3,612 lb, 245 lb more than a basic Belvedere two-door sedan. (Contrary to what you might think, the AMA specs indicate that with the 383 engine, TorqueFlite cars actually weighed 47 lb less than with a four-speed.)

 

This weight did not mean the Road Runner was well-equipped or notably plush:

Keeping the price at a reasonable level ($3034 base price) makes the Road Runner a sort of Scotsman’s Supercar. It’s far from plush—in fact, it looks like it borrowed a taxicab’s interior. Yet it doesn’t scrimp in those areas that make an enthusiast’s adrenalin [sic] boil. Standard equipment includes a highly tuned 383-cid V-8; four-speed all-synchro transmission: 11-in. drum brakes front and rear, heavy-duty suspension with firm springs and shocks plus thicker torsion bars and antiroll bar; F-70-15 [sic] Wide Oval redline tires; extra-duty cooling system with viscous-drive fan; tachometer; plus unique exterior trim and emblems.

There are a number of errors in the above paragraph that I think it’s worth pointing out for the record:

  1. The quoted base price ($3,034) was for the Road Runner hardtop, which was added in January 1968; the two-door pillared coupe, which appears to be what CL tested, listed for $2,896 at that time.
  2. Standard Road Runner tires were F70-14, red streak or white streak. Cars with the 426 Hemi engine had F70-15 tires, but both the dealer data book and price guide suggest that 15-inch wheels weren’t available as a factory option with the 383 engine, although getting a dealer to install them wouldn’t have been difficult.
  3. With the 383 engine, the extra-duty cooling system, radiator shroud, and viscous-drive fan were not standard, but were packaged with the $87.50 “hi-performance axle group,” which also included a 9.75-inch Dana heavy-duty axle with 3.55 gears. Both the panel and the main text indicate that their TorqueFlite-equipped car had the standard 3.23 Sure-Grip axle, which didn’t include the beefier axle or additional cooling.
  4. A tachometer was an extra-cost option on the Road Runner, as it was on all V-8 Belvedere/Satellite models in 1968.

 

Under the hood:

The Road Runner’s standard 383 engine isn’t the same as used in other Chrysler Corp. cars. It delivers 335 bhp at 5200 rpm, 425 Ib.-ft. of torque at 3400 rpm. This increase of horsepower over Chrysler’s three other versions of the 383 (290. 300. and 330 bhp) comes about for several reasons. First the Road Runner 383 uses the corporation’s 440-cid Super Commando heads and camshaft. This lends higher valve lift (0.450/0.465 intake and exhaust as against the normal 383’s 0.425/0.437) and longer duration. Second, the Road Runner’s standard 383 comes with a large-runner intake manifold and a Carter AVS-4426S four-barrel carburetor with 1.44-in.-diameter intake barrels and 1.69-in.-diameter secondaries. Add to this the 440’s crankcase windage tray, twin exhausts and unsilenced air cleaner as standard equipment, and this becomes a pretty potent combination.

If you want to be particular, AMA specifications list the automatic 383 Road Runner as having a Carter AVS-4401S carburetor, although the primary and secondary diameters were the same as with manual transmission cars. A later retrospective in Hot Rod also cautions that contrary to some early claims, the intake manifold of the A139 383 engine used in the Road Runner was NOT interchangeable with the 440 manifold.

 

With the 383 and TorqueFlite (an extra $38.95 on this car), the Road Runner had good street performance, but was limited on the dragstrip by the inadequacy of the stock tires:

In driving the Road Runner, we found the engine is very strong in every-day traffic—lots of punch and admirable flexibility. While it idles on the lumpy side, it quickly smooths out and purrs along beautifully at high cruising speeds. The car felt free and fast at 70–80, with lots of torque and revs left for quick passing. Our test car came with TorqueFlite and 3.23:1 axle ratio. Torque at takeoff was more than the street tires could handle. We noticed this both in city driving and at the strip. You simply have to be careful starting out, otherwise you find the rear tires breaking loose immediately. This tendency would undoubtedly be magnified with the four-speed transmission, and actually we consider both transmissions equal in spanning the quarter mile with the 383.

The data panel indicates that the Road Runner had Goodyear Speedway Wide Tread F70-14 tires. Car Life had also tried and disliked the Wide Tread tires (in E70-14 size) on the first AMC Javelin they’d tested six months earlier, which had similar traction problems in acceleration runs.

Car Life, May 1968, page 57, second page of Plymouth Road Runner road test, with a series of B&W photos above the main text (the engine with the air cleaner removed; the air cleaner cover, a styled wheel, overhead front and rear 3q shots of the car on a dirt road, and a shot of the right rear fender)

The Car Life acceleration times for the Road Runner were disappointing for what was supposed to be a high-performance car:

  • 0 to 30 mph: 3.1 sec.
  • 0 to 60 mph: 7.3 sec.
  • 0 to 100 mph: 19.0 sec.
  • Standing ¼-mile: 15.37 sec. at 91.4 mph
  • Top speed: 122 mph at 5,200 rpm
  • Test average fuel consumption: 10.8 mpg

As with most Car Life test results, these figures were with two aboard (since a second crewman was needed to operate the test equipment). Although the editors felt that “stickier tires and less weight would probably have let us break into the high 14s,” the mediocre trap speed (91.4 mph) and lackluster 19-second 0 to 100 mph time suggest a power deficit that couldn’t be explained by traction alone. (The CL Javelin 343 had been no easier to launch, but it reached 100 mph in 17.7 seconds despite theoretically having 55 fewer gross horsepower.)

 

Car Life also found the Road Runner drum brakes poor:

Brakes turned out even more disappointing than the Road Runner’s acceleration. During the first panic stop from 80 mph, the cold rear drums locked up tight, the rear end began wagging like a dog’s tail, and we had to get off the pedal to regain control. During that first stop, our decelerometer registered 17 ft./sec.²—not very good in anybody’s book. As the rear drums warmed up, they began to fade and give the front drums a chance to do some work, and readings went up (maximum: 20 ft./sec.²—on the third, fourth, and fifth stops). After that, and giving the brakes about a minute’s rest between stops, all four drums started fading; and although we could control the car and keep it straight, meter readings leveled off at about 19. The brakes’ poor performance can be blamed on badly chosen front/rear brake proportioning, and we feel Chrysler engineers should take another hard look at the valving here.

Front disc brakes were optional on the 1968 Road Runner for an extra $72.95 (plus $41.75 for the power booster, which the CL test car already had). Whether discs would have significantly improved braking performance is a more difficult question. Car Life tests of other contemporary Mopar cars with front discs had encountered even worse problems with front/rear proportioning, which created a significant risk of getting sideways in a panic stop. Chrysler eventually sorted this out — a subsequent CL test of a 1969 Dodge Super Bee with front discs found its braking performance outstanding — but it seems to have still been a work in progress in 1968.

 

Handling was better:

The Road Runner rides and handles predictably enough. With its fairly heavy engine in front, there’s a good deal of understeer. It’s not worrisome, though, and easily correctable by applying more power to the rear wheels when storming around fast turns. Power steering, which our test car had, gives an overall ratio of 18.8:1—not terribly fast, but ample. Chrysler’s power steering is such that the driver loses almost all road feel, so in tight corners we had to judge how hard the front tires were scrubbing by listening to them squeal and by the car’s general attitude.

There’s relatively little body roll with the H-D suspension. At speeds up to about 50 mph, the Road Runner rides much better than most cars with stiff handling packages. Over 50, though, a good deal of bobble and jostle comes through, and on long trips at sustained high speeds, this can become annoying to the occupants.

Heavy-duty suspension was standard on the Road Runner in 1968, giving wheel rates of 130 lb/inch in front and 151 lb/inch in back, so it wasn’t surprising that the ride was rather stiff.

 

Aside from the downmarket ambiance of the cabin, the editors though the seat was too low and the steering wheel too high, which demanded an arms-out driving style they found tiring. They were also perplexed that there was no oil pressure gauge to accompany the ammeter and temperature gauge, and found the 8,000 rpm tachometer — jammed into a space originally intended for a clock — difficult to read.

One of the cost-saving measures on the Road Runner was simple swing-out rear quarter windows. Car Life actually appreciated these, noting that the quarter windows and vent windows “give better circulation than most cars today.”

Car Life, May 1968, page 58, third page of Plymouth Road Runner road test, with B&W photos above the text of the trunk and bench front seat; below the text is the first half of the data panel, with an inset front view of the car

The photo captions at the top of the page read, “TRUNK SPACE is cavernous, and low sill means easy loading. SPARTAN interior puts more money into performance.”

Car Life concluded:

For people who yearn for the ultimate in performance from the Road Runner, there’s the street Hemi 426 offered optionally. While this adds at least $714 plus mandatory options to the price, it also adds a good deal to straight-line performance. With the 426, the Road Runner becomes the fastest stock machine in the strip, and it’s even a tractable car on the street if it’s kept in perfect tune. This engine, though, is extremely difficult to tune properly, so unless you can do it yourself, unless you live near one of the handful of dealers in the country who know how to tune it, and unless you’re prepared to spoil the Road Runner’s economy advantage both initial price and the long-range maintenance cost (the 426 makes this a $4000-plus automobile), by all means specify the 383 engine.

Despite the editors’ caution, if you wanted the 426 Hemi engine in 1968, ordering it in the Road Runner was probably your best bet. A Hemi Road Runner was neither light nor especially cheap, but it was the lightest, cheapest model that offered the 426 as a regular production option in 1968. Buyers seem to have reached the same conclusion: Almost half of the 426 Hemi engines Chrysler Corporation sold in 1968 went under Road Runner hoods, although I found conflicting Hemi Road Runner production totals of 1,009, 1,019, and 1,109 units. (At least two of these are almost certainly typos, but as to which, your guess is as good as mine.)

 

I have some questions about the prices specified in the CL data panel. As I mentioned earlier, it appears they had the pillared coupe, not the hardtop, whose base price was $2,896, not $3,034. If the car really had the 3.23 axle ratio specified, which seems likely, it probably did NOT have the hi-performance axle group (which included a 3.55 axle), but rather the standard Sure-Grip differential ($42.35). Their car also had some options not specified here, like power brakes ($41.75), a vinyl roof ($81.60), and head restraints ($43.90, and not yet required by federal law for another year). In any event, the quoted $3,637 as-tested price was probably about right, but it seems to have been a case of doing the math wrong and still ending up with the correct answer.

 

Car and Driver‘s four-speed test car ended up even more expensive ($3,753.40), laden — to their frustration — with extra chrome trim, light packages, and other incidental options. If you weren’t careful with the minor options, this budget Supercar could end up with a regular Supercar price tag, at which point you might have been better off with the Plymouth GTX. The GTX started at $321 more than a Road Runner hardtop, but that included the Super Commando 440 engine, your choice of TorqueFlite or four-speed, and less taxicab-like interior.

Car Life, May 1968, page 59, final page of Plymouth Road Runner road test, with B&W photos of a tester behind the wheel on a racetrack above the second half of the data panel; there is no main text on this page
The photo caption reads, “BRAKE TESTS from 80 mph, recorded by decelerometer on windshield, were disappointing. All-drum system faded and lacked balance.”

 

I’m sure commenters will hasten to point out that a properly set up Road Runner was faster than this CL tester. However, Car Life made a point of testing cars in the form in which they were received, without tinkering. Since most of their cars came from manufacturer press fleets, some weren’t quite broken in, while others had previously been thrashed by other testers and were clearly rather tired. Popular Hot Rodding (January 1968) had previously previously driven a dark-colored Road Runner coupe with a vinyl top and TorqueFlite, which I think might have been the same car CL drove. PHR managed quarter-mile elapsed times “ranging from 14.90 to 15.55” seconds with trap speeds “in the 95–96 mph area,” so if it was the same car featured in this Car Life test, some of its horses seem to have wandered out of the stable in the interim. (PHR had complained of unexplained engine surge issues during their test, remarking that “Plymouth has a carburetion bug to be worked out.”)

 

There was certainly more performance to be had if you cared to tinker. CARS claimed a far more impressive 14.65-second elapsed time for a four-speed/383 Road Runner, with a trap speed of 100.5 mph. That was more in keeping with the “Supercar” portion of the “budget Supercar” equation, but extracting that performance involved removing the emissions controls, replacing the Chrysler Cleaner Air Package distributor with a Mallory aftermarket unit, advancing the timing, re-jetting the carburetor, removing the air cleaner, replacing the stock four-speed shifter with a Hurst Competition-Plus unit, and adding aftermarket spring clamps and a pinion snubber to the rear axle to allow harder launches. These weren’t huge modifications, and weren’t terribly expensive if you were equipped to do the work yourself, but the result was that the CARS tester was not showroom stock, which the Car Life car was.

 

This gets back to the point Car Life had made at the outset about emulating what performance-minded buyers might do on their own. As a cheaper platform for the usual enthusiast aftermarket tinkering, the Road Runner was a good starting point, at least if you were stubborn enough to keep the dealer from fattening up the bottom line with deluxe moldings and decor groups. Considered strictly as a turnkey Supercar, the 383 Road Runner was not in the same league as the GTX, even allowing for the possibility that the CL test car’s engine was mechanically under the weather.

 

Nonetheless, the Road Runner was a great marketing concept. Chrysler-Plymouth management had been very uneasy with the idea of sticking a cartoon character on their car, and both the division and a lot of critics were aghast at the “Voice of the Road Runner” horn, but the package went over very well with the intended audience: The Road Runner sold 44,599 cars in 1968 (29,240 coupes, 15,359 hardtops), while the GTX managed only 18,940. Performance counted for a lot in this specialist class, but image was everything, and the Road Runner had a name and image no one was likely to forget.

Related Reading

Vintage Car & Driver Comparison Test: 1969 Hemi Roadrunner, Chevelle 396, Ford Cobra, Cyclone CJ, Superbee and GTO The Judge – “Six Econo-Racers” (by Paul N)
Curbside Classic: 1969 Plymouth Road Runner Hardtop — Spring Is Here! (by Mike Butts)
Vintage Car Life Review: 1969 Dodge Coronet Super Bee 383 – “Lives Up To Its Decals” (by me)