Plymouth Road Runner Tires

Plymouth Road Runner uses three tire sizes across the 1970 to 1974 range: F70-14, F78-14, and G70-14. F70-14 appears from 1970 through 1973, F78-14 appears in 1971, and G70-14 appears from 1972 through 1974. All three sizes are alphanumeric bias-ply sizes built for 14-inch rims, with F70-14 generally fitting 6.00 to 7.00-inch rims, F78-14 fitting 5.00 to 7.00-inch rims, and G70-14 fitting roughly 6.0 or 6.50 through 7.00 or 8.0-inch rims depending on the tire chosen.

The practical takeaway is that year alone does not settle the question on every Plymouth Road Runner. A 1971, 1972, or 1973 car needs to be checked against its actual wheel setup and the tire size already on the car, if that size is known to be correct. The safest approach is to compare the wheel width, the size called for on original paperwork, and the styling goal of the car before selecting among the listed 14-inch options.

F70-14 is an alphanumeric bias-ply size used on Plymouth Road Runner applications from 1970 through 1973. The F identifies the tire's relative section class, the 70 identifies its profile series, and the 14 is the wheel diameter in inches. It is not a metric size and it is not a radial size, because there is no R in the code.

For a Plymouth Road Runner owner, that means F70-14 should be treated as a period-style bias-ply fitment rather than converted casually from modern radial sizing. The wheel itself still needs to fall within the tire's approved rim width range, which is commonly 6.00 to 7.00 inches for the available products in this size. If your car has been changed from its original wheel setup, verify the wheel width before assuming F70-14 is still the right choice.

The 1971 Plymouth Road Runner has two listed sizes because both F70-14 and F78-14 appear for that model year. Both are 14-inch alphanumeric bias-ply sizes, so the difference is not wheel diameter or construction type. The split points instead to a configuration difference within the model year, such as trim, wheel package, or another factory setup distinction.

That matters because a 1971 Plymouth Road Runner owner should not pick a tire by year alone. Check the size on the current wheel, confirm the wheel width, and compare that information to original vehicle paperwork or a knowledgeable Mopar specialist if the car has been restored or modified. Once the correct 1971 configuration is identified, the choice between F70-14 and F78-14 becomes much more straightforward.

Every listed Plymouth Road Runner tire in this range is a bias-ply design in an alphanumeric format, so a tube is required. That applies to F70-14, F78-14, and G70-14 as they are offered here. There are no radial options in this fitment set, and nothing in the available range changes the basic tube-required character of these tires.

For the owner, that means tire service should be handled with the tube requirement in mind rather than treating these like modern tubeless passenger tires. Tube condition, flap use where appropriate, and clean, correctly prepared wheel surfaces all matter to long-term reliability. If the car has aftermarket wheels or mixed parts from another Mopar application, confirm that the wheel construction is suitable for the selected bias-ply and tube arrangement.

A 1972 Plymouth Road Runner can use either F70-14 or G70-14, and both are 14-inch bias-ply sizes. The difference is in the section class and overall fitment character rather than wheel diameter. Available F70-14 products commonly fit 6.00 to 7.00-inch rims, while G70-14 products fit wider approved ranges that reach up to 7.00 or 8.0 inches depending on the tire.

That means the wheel width on the actual 1972 Plymouth Road Runner is one of the most useful checks you can make. If the car still has original wheels, compare the wheel width and existing size against factory paperwork or restoration records. If the car has been changed over the years, identify whether it is set up for the narrower F70-14 or the wider G70-14 before choosing a sidewall style or tire series.

Plymouth Road Runner tires are available with several sidewall styles in this size range, including redline, RWL, pin white stripe, blackwall, and wide whitewall. F70-14 offers redline, RWL, and pin white stripe options, F78-14 is listed with a 2.375-inch wide whitewall, and G70-14 includes redline, RWL, pin white stripe, and blackwall choices. That gives Road Runner owners a wide spread of appearance options within period-style bias-ply construction.

The right sidewall style depends on how the car is being restored or presented. Muscle-era Road Runners are often associated with performance-oriented looks such as redlines or raised white letters, while a wide whitewall F78-14 creates a distinctly different visual effect. If authenticity matters, compare the car's trim level, build date, and restoration goal before choosing the sidewall treatment that best suits the specific Plymouth Road Runner.

Three brands appear in the Plymouth Road Runner tire range here: Firestone, Goodyear, and Coker Classic. Firestone products are offered in the Wide Oval series, Goodyear products appear in the Custom Wide Tread and Speedway Wide Tread series, and Coker Classic appears in a classic bias-ply whitewall application. The brand spread is strongest in F70-14 and G70-14, while F78-14 is represented by a single Coker Classic option.

For an owner, that means brand choice is tied not only to size but also to the visual style and restoration theme of the car. If you are matching a period muscle look, the available Firestone and Goodyear offerings will feel different visually from the Coker Classic whitewall option. Start by confirming the correct size, then narrow the selection by the sidewall look and tire series that best match your Plymouth Road Runner.

Plymouth Road Runner tires are available in several series, including Firestone Wide Oval, Goodyear Custom Wide Tread, Goodyear Speedway Wide Tread, and Coker Classic Bias Ply. All of them are bias-ply constructions in the listed Road Runner sizes, but they differ in branding, tread family, and sidewall presentation. Wide Oval appears with redline, RWL, and pin white stripe options, Custom Wide Tread spans redline, RWL, blackwall, and pin white stripe, Speedway Wide Tread appears in F70-14, and Coker Classic Bias Ply is represented by a wide whitewall F78-14.

That difference matters mainly in appearance and period character rather than in switching between radial and bias technologies, since all of these Road Runner offerings are bias-ply. A buyer choosing for show presentation may focus on sidewall treatment and series branding, while a driver restoring a specific year may start from the size and then choose the series that best fits the car's intended look. Keep the vehicle's exact year and approved wheel width at the center of the decision.

A Plymouth Road Runner should be stored in a cool, dry, dark environment with the tires kept away from direct sunlight, ozone sources, and large temperature swings. Electric motors, battery chargers, welders, and furnaces can all accelerate rubber aging over time. Clean floors, stable inflation, and minimizing long periods of weight on one contact patch all help preserve bias-ply collector tires.

For a stored Plymouth Road Runner, it is wise to move the car periodically or use methods that reduce flat spotting during long idle periods. Keep the car free of leaking fluids that can contact the sidewalls, and avoid parking on damp ground or bare earth. If the car is a seasonal driver, include the tires in your off-season preparation rather than treating them as passive parts that can simply sit untouched.

Tires on a Plymouth Road Runner should be visually inspected before each drive and given a more thorough inspection several times during the driving season. Collector cars often spend long periods parked, which can hide pressure loss, cracking, bead issues, or impact damage until the car is finally moved. Bias-ply tires also deserve close attention to tread separation, sidewall condition, and any signs of tube-related trouble.

A practical routine is to check inflation, sidewalls, tread, and valve area before the car leaves the garage. If the Plymouth Road Runner has recently come out of storage, has sat through major temperature changes, or has been driven at highway speeds, inspect it again afterward. Any vibration, pull, thump, or sudden change in ride quality should trigger an immediate recheck before the next outing.

Tires on a Plymouth Road Runner should be replaced when age, cracking, hardening, deformation, repeated air loss, or structural concerns appear, even if the tread still looks usable. Collector tires often age out long before they wear out because the car sees limited annual mileage. The same principle applies to bias-ply tires that have spent years on a stored car and may look better than they actually are internally.

That means a Plymouth Road Runner owner should evaluate tires by condition and age history, not tread depth alone. A tire that is several years old, has unknown storage history, or shows sidewall and casing changes deserves a professional inspection before continued road use. Replacement timing should err on the conservative side if the car will be driven beyond local show, cruise, or fair-weather use.

Plymouth Road Runner fitment in this range includes F70-14, F78-14, and G70-14, all in bias-ply construction, with available series including Firestone Wide Oval, Goodyear Custom Wide Tread, Goodyear Speedway Wide Tread, and Coker Classic Bias Ply. More than one size appears in several years, and more than one series is represented across the model run. That means there is not one single tire answer that covers every Road Runner from 1970 through 1974.

For restoration work, the exact original tire depends on the specific year and configuration of the Plymouth Road Runner being restored. The best path is to match the size first, then compare the sidewall style and tire series to surviving factory paperwork, broadcast sheet information, judging standards, or marque-club references. That approach avoids choosing a visually appealing tire that does not line up with the car's actual build.

Correct tire fitment can absolutely affect how a Plymouth Road Runner is judged and, in many cases, how seriously the restoration is taken. Size, sidewall style, and overall period presentation all contribute to whether the car looks properly finished for its year and configuration. A Road Runner wearing the wrong profile, the wrong sidewall treatment, or a mismatched visual style can stand out quickly to experienced Mopar enthusiasts.

That does not mean every owner must pursue strict concours correctness, but it does mean tire choice should match the intended use of the car. For high-level restoration or judged events, compare your Plymouth Road Runner against marque standards and period reference material before making the final selection. For a driver-quality restoration, staying within the correct size family and a believable era-correct appearance usually provides the right balance.

Firestone Wide Oval and Goodyear Custom Wide Tread are both offered for Plymouth Road Runner applications as bias-ply tires, but they represent different branded performance-era series and sidewall combinations. In the listed Road Runner sizes, Firestone Wide Oval appears with redline, RWL, and pin white stripe versions, while Goodyear Custom Wide Tread appears with redline, RWL, blackwall, and pin white stripe depending on size. The size availability also differs slightly, with both series represented in F70-14 and G70-14.

For restoration purposes, the choice between those two series is mainly about period look and brand presentation once the correct size has been established. A Plymouth Road Runner owner trying to mirror a particular build theme may favor one brand family over the other, especially if the car's photos, paperwork, or restoration target point in that direction. The key is to keep the size correct first and treat the series choice as the finishing detail.

These Plymouth Road Runner tires are purpose-built collector bias-ply tires and can be used on public roads when they are correctly fitted, properly maintained, and matched to a mechanically sound car. They are not modern high-performance radials, so their behavior, ride, and response will reflect period construction. The available sizes also need to be matched correctly to the wheel width and vehicle configuration for safe operation.

For a road-driven Plymouth Road Runner, safe use starts with realistic expectations and careful preparation. Confirm inflation, inspect the tires before driving, and make sure the steering, suspension, brakes, and alignment are all in good condition. If the car has been modified for wider wheels or modern driving habits, evaluate whether the selected bias-ply tire still suits the way the car will actually be used.

Before driving a Plymouth Road Runner, check tire pressure, sidewall condition, tread condition, and any signs of leakage or casing damage. Because these are bias-ply applications, it is also wise to watch for flat spotting after storage and for any change in feel once the car begins moving. The wheel width, valve area, and general seating of the tire on the rim should also look correct.

Beyond the tires themselves, a Plymouth Road Runner should be treated as a whole collector vehicle system. Verify that the brakes are responsive, the steering is predictable, and the suspension is not introducing shake or wander that could be mistaken for a tire problem. Any newly restored or long-stored car deserves a short, cautious test drive before heading onto faster roads.

A Plymouth Road Runner on period-style bias-ply tires should be driven at sensible speeds that respect both the age of the vehicle and the characteristics of the tire construction. Even when new, bias-ply tires do not behave like modern radials in lane changes, braking transitions, or sustained high-speed cruising. The correct approach is to treat the car as a vintage muscle car rather than assume modern freeway manners.

In practice, that means building speed gradually, avoiding abrupt steering inputs, and leaving generous braking distance. If the Plymouth Road Runner has sat for long periods, has fresh restoration work, or is running on tires that are new to the car, start with shorter drives and moderate speeds until everything is fully sorted. Mechanical condition, alignment, and inflation all play a major role in how comfortable the car feels at speed.