1956 Plymouth Tire Fitment Guide

1956 Plymouth vehicles use two tire sizes: 670-15 and 710-15. Both sizes apply across the full model range here, including the P28-1, P28-2, P28-3, P29-1, P29-2, and P29-3 model families, and both mount on 15-inch wheels. For 670-15, listed rim-width recommendations run from 4.50 to 6.00 inches depending on the product. For 710-15, listed rim-width recommendations run from 5.00 to 5.50 inches.

That means most 1956 Plymouth owners do not need to solve a model-specific diameter issue first. The practical next step is to compare your wheel width and decide whether you want the 670-15 or 710-15 size, then choose the sidewall style that best matches your restoration. If the car still wears original wheels, verify the wheel width before ordering, since one product in 670-15 is intended for a narrower rim range than another.

A 670-15 marking on a 1956 Plymouth tire is a numeric bias-ply size. The 6.70 figure refers to the tire’s nominal section width in inches, and the 15 refers to the wheel diameter in inches. It is not a modern metric size, and it does not express width, aspect ratio, and construction in the same way a later radial code would.

That older numeric format matters because buyers sometimes expect a direct modern-style translation from the sidewall, and that is not how a mid-1950s Plymouth tire is labeled. When comparing products in 670-15, look beyond the code itself and also compare sidewall style, brand, and the recommended rim-width range. Those details affect whether the tire is the right match for your wheel and whether the finished car reads more like a blackwall driver or a whitewall restoration.

Yes, the 1956 Plymouth models covered here share the same two tire sizes: 670-15 and 710-15. That includes both the P28 and P29 model families, and both sizes use 15-inch rims. Plymouth owners therefore have a simpler fitment path than buyers working with a year and make that changed tire diameter from one model line to another.

Shared sizing does not mean every tire choice will look identical on every car. A whitewall treatment can change the visual character of a restoration, and the difference between 670-15 and 710-15 can also affect the stance and period impression. Once you confirm that your car falls within the P28 or P29 family shown here, the smarter comparison is between size preference, wheel-width compatibility, and sidewall appearance rather than between different model-only fitments.

Both 670-15 and 710-15 are correct-style bias-ply choices for 1956 Plymouth vehicles, and both fit 15-inch wheels. The difference is not a bias-ply versus radial decision here, since both sizes stay within the same period construction family. Instead, the choice comes down to selecting the original-style numeric size you want for your car and making sure the tire’s recommended rim-width range matches the wheel you are using.

A buyer focused on period presentation can compare the available sidewall treatments first, because a 1950s Plymouth’s final look changes dramatically between blackwall and wide whitewall tires. Then compare the wheel-width requirement for the specific product, since 670-15 offerings span more than one rim-width range while 710-15 products shown here concentrate in a narrower band. That approach keeps the selection process grounded in fitment and appearance rather than guesswork.

1956 Plymouth tires are available in both blackwall and wide whitewall styles in each listed size. The 670-15 range includes blackwall and wide whitewall versions, and the 710-15 range does as well. That gives Plymouth owners flexibility whether they want a plainer, more understated look or the bright white sidewall presentation many collectors associate with upscale mid-1950s American cars.

For show-oriented restorations, wide whitewalls are often chosen because they complement the chrome-heavy styling and dramatic body lines Plymouth used in 1956. Blackwalls can still be the right visual answer for a more restrained build or for owners who prefer a less ornate appearance. The key is to choose the sidewall style that matches the story you want the car to tell, then confirm that the exact tire you choose also suits your wheel width and size preference.

Several brands cover 1956 Plymouth fitments. In 670-15, available brands include Firestone, US Royal, Coker Classic, and Universal Vintage Tire. In 710-15, available brands include BFGoodrich and Firestone. All of the products listed here stay within the bias-ply construction style appropriate to the period fitment family used on these Plymouth models.

Brand choice on a 1956 Plymouth often comes down to a combination of sidewall appearance, preferred brand heritage, and the exact wheel-width range the tire supports. Some owners want a familiar American brand name that looks at home on a Forward Look-era car, while others are primarily sorting by size and sidewall treatment. Narrow the field by choosing your tire size first, then compare which brands offer the visual presentation and wheel compatibility you want.

Rim-width requirements for 1956 Plymouth tires depend on the size and the exact product. In 670-15, listed recommendations run from 4.50 to 5.00 inches on some products and 5.00 to 6.00 inches on others. In 710-15, the listed recommendation is 5.00 to 5.50 inches. Both sizes mount on 15-inch wheels, but wheel width still needs to match the tire you choose.

That variation is why two tires carrying the same basic size can still differ in wheel suitability. Before mounting a new set, measure the wheel or confirm the wheel specification through a trusted source for your car. If your 1956 Plymouth still has original wheels, pay attention to whether the tire you prefer was designed around a narrower or wider rim range so the casing profile and fit remain appropriate.

A 1956 Plymouth can use both listed tire sizes on 15-inch wheels because 670-15 and 710-15 share the same rim diameter. That makes diameter compatibility straightforward across the two sizes and across both the P28 and P29 model families. Wheel width is the part that still needs attention, since the recommended ranges are not identical for every product in 670-15 or 710-15.

In practical terms, an original 15-inch wheel may be compatible with either size, but you should match the actual wheel width to the specific tire’s approved range before mounting. That step matters on a collector Plymouth because old wheels may have been changed over the decades, even when they still look factory-correct. Verifying width first helps avoid choosing a tire that is correct in diameter but not ideal for the wheel the car currently wears.

A stored 1956 Plymouth should be kept in a cool, dry, dark space away from direct sunlight, electric motors, welders, battery chargers, and other ozone-producing equipment that can accelerate rubber aging. Keep the tires inflated to a sensible storage pressure, roll the car periodically if possible, and make sure it is not sitting on a damp surface for long periods. Bias-ply tires are especially prone to developing temporary flat spots after extended static storage.

If the car will sit for months at a time, many collectors either move it occasionally or support it in a way that reduces continuous load on one contact patch. The goal is not just preserving tread, but protecting sidewalls and carcass shape on a low-use vehicle. A little prevention during storage helps the car drive more smoothly when it comes back out and keeps a fresh-looking set of classic-style tires from aging prematurely.

Tires on a 1956 Plymouth are usually aged out before they are worn out, since collector cars often see limited annual mileage. A good rule is to begin evaluating tires closely once they are about five to seven years old and to treat the ten-year point as a strong replacement consideration regardless of remaining tread depth. The DOT date code on the tire helps establish age, which matters more than mileage alone on a hobby vehicle.

That age-based approach is especially important for a mid-1950s car because long storage periods, sunlight exposure, and underuse can harden rubber even when the tread still looks respectable. A tire that appears fine in the garage can still have age-related cracking or reduced flexibility once driven at speed. If your 1956 Plymouth has older tires of uncertain age, inspect them carefully and make replacement decisions based on condition and date, not just appearance.

Tires on a 1956 Plymouth should be inspected before every drive and again before any longer outing. Look for sidewall cracking, weather checking, bulges, cuts, irregular wear, and signs that the tire is losing pressure between uses. Because collector cars often sit for stretches, check the spare as well rather than assuming it is ready simply because it has not been used recently.

A quick inspection matters more on a lightly driven classic than many owners realize, since storage-related aging can advance between drives. Make pressure checks part of the routine and pay close attention after the car has been parked for weeks or months. Catching small issues early helps prevent roadside trouble and gives you time to correct a tire, wheel, or valve-related problem before taking the Plymouth farther from home.

A 1956 Plymouth P28-1, 28-2, or 28-3 would have been fitted in the bias-ply era, and the sizes used across the 1956 Plymouth range here are 670-15 and 710-15. That aligns with what buyers expect for a mid-1950s American passenger car, when bias-ply construction was still standard equipment. Original-equipment branding could vary by market and delivery history, so size, construction type, and sidewall appearance are the most reliable starting points for an authentic restoration.

For a restoration aiming at factory presentation, begin by confirming which of the two listed sizes belongs on your specific car, then choose a sidewall style that matches the look you are trying to recreate. If the car will be judged, marque clubs and Plymouth specialists are the right place to confirm market- or trim-specific expectations. That extra step helps ensure the tire choice supports the car’s story instead of simply fitting the wheel.

Correct tire fitment matters on a 1956 Plymouth because judges and knowledgeable enthusiasts notice the combination of size, construction, and sidewall style very quickly. A mid-1950s Plymouth shown for authenticity should wear a tire that looks appropriate to the era, which generally means a proper bias-ply size and a sidewall treatment consistent with the way the car is being presented. Even when a tire physically fits, an obviously out-of-period appearance can distract from an otherwise careful restoration.

That does not mean every event applies the same standard, but it does mean tires should be chosen as part of the restoration plan rather than as an afterthought. A wide whitewall may be exactly right for one car’s intended presentation, while a blackwall may better suit another. If you plan to compete, check event rules or consult Plymouth-focused clubs so your final choice aligns with the judging style you expect to encounter.

On a 1956 Plymouth, the difference between blackwall and wide whitewall tires is mainly visual rather than dimensional within the same size. Both 670-15 and 710-15 are available in blackwall and wide whitewall versions, so the underlying fitment can remain the same while the car’s overall presentation changes substantially. Whitewall width was a defining styling cue in the 1950s, especially on American cars with prominent chrome and dramatic body lines.

A wide whitewall tends to emphasize the car’s period character and often suits a fully trimmed show car or a restoration that leans into the era’s styling. A blackwall produces a more restrained look and can work well on a driver or on a build with a simpler visual theme. Either choice can be correct for the right restoration, but the sidewall style should support the appearance standard you are aiming to achieve.

1956 Plymouth tires can be suitable for highway use when they are the correct size, in good condition, properly inflated, and mounted on sound wheels. The sizes listed here are bias-ply tires, so their on-road feel will reflect period construction rather than the response of a modern radial. Highway safety on a mid-1950s Plymouth also depends heavily on the car’s overall mechanical condition, including steering, suspension, brakes, and wheel condition, not just the tires alone.

For a collector car that sees occasional road use, the practical question is less about whether the tire can go on the highway and more about whether the entire car is prepared for the trip. Keep speeds appropriate to the vehicle’s age, handling, and condition, and inspect the tires carefully before longer drives. A fresh, correctly fitted bias-ply tire can serve well, but it should be used with the expectations and maintenance discipline a 1956 Plymouth deserves.

Several 1956 Plymouth tires in these fitments carry load-and-pressure markings of 1450 pounds at 32 psi in 670-15 and 1550 pounds at 32 psi in both 670-15 and 710-15, depending on the product. Those figures are the tire’s rated load capacity at that pressure, not a universal instruction to inflate every 1956 Plymouth tire to the same number without context. The car’s original recommended inflation setting should come from the owner’s manual or factory literature for the specific model.

Use the vehicle recommendation as your baseline, then confirm that it remains appropriate for the exact reproduction tire you are fitting. Do not transfer a pressure figure from one size to another just because both fit 15-inch wheels. If your Plymouth carries passengers infrequently and sees mostly fair-weather use, pressure still needs regular checking, since collector cars can lose air gradually while parked and low pressure is especially hard on classic-style casings.

Before a longer drive in a 1956 Plymouth, inspect each tire for cracks, cuts, bulges, uneven wear, and any sign of damage from age or impact. Confirm air pressure, check that the valve stems are sound, and inspect the spare so it is usable if needed. Since both listed sizes are classic-style bias-ply fitments, also make sure the wheels themselves are in good condition and that the tires have not developed severe flat spotting during storage.

Tires are only one part of the preparation, but they are one of the easiest places to catch a problem before it turns into a roadside interruption. A longer trip is also a good reason to verify wheel fasteners, steering feel, brake operation, and overall vehicle readiness. Giving the Plymouth a calm, methodical pre-drive inspection helps you enjoy the trip as the car was meant to be enjoyed, rather than worrying about avoidable failures.