1948 Plymouth Tire Fitment Guide

1948 Plymouth vehicles covered here use one tire size: 670-15. That size applies to the 1948 Plymouth Deluxe and mounts on a 15-inch wheel. Available products in this size are bias-ply tires, and listed fitments cover rim widths from 4.50 to 6.00 inches depending on the specific tire you choose.

That makes fitment simpler than on year-make pages with multiple sizes, but you should still confirm the wheel on the car before ordering. A Plymouth that has been restored, modified, or swapped to different wheels may need a closer check of actual rim width and sidewall preference, especially if you are choosing between blackwall and whitewall visual styles.

On a 1948 Plymouth tire, 670-15 is a numeric bias-ply size. The 6.70 refers to the nominal section width in inches, and the 15 refers to the wheel diameter in inches. Because it is a numeric size without an R in the code, it identifies a bias-ply construction rather than a radial tire format.

That matters because the code tells you both the general proportions and the type of tire behavior to expect from a period-style fitment. If your goal is to keep a 1948 Plymouth looking and feeling true to its era, 670-15 is the size language you want to see on the sidewall, and then the remaining choice becomes brand and sidewall presentation.

Within the 1948 Plymouth coverage here, yes. The Plymouth Deluxe uses 670-15, so there is no split in fitment across multiple Plymouth model cores on this page. The wheel diameter stays at 15 inches, and the available tires remain within the same bias-ply family.

That simplifies research for an owner who already knows they have a 1948 Plymouth Deluxe. Instead of sorting through multiple widths or rim diameters, you can focus on matching the sidewall style to the character of the car, whether that means a straightforward blackwall look or a wide whitewall presentation more in line with many period restorations.

1948 Plymouth tires in 670-15 are available in both Blackwall and Wide Whitewall styles. Firestone and Universal Vintage Tire offer blackwall versions, while US Royal and Coker Classic offer wide whitewall versions in this size. All of these choices stay within the correct bias-ply construction family for the year.

The visual difference is significant on a late-1940s Plymouth because sidewall treatment changes the whole stance and presentation of the car. Blackwalls suit a plainer, workmanlike look, while wide whitewalls better match the dressier postwar American style many restorers want. Choosing between them is usually an authenticity and appearance decision rather than a fitment one.

Four brands offer 670-15 tires for 1948 Plymouth vehicles: Firestone, US Royal, Coker Classic, and Universal Vintage Tire. Each is offered in bias-ply construction, which aligns with what buyers typically seek for a postwar Plymouth restoration. The available sidewall looks span blackwall and wide whitewall depending on brand and series.

Brand choice usually comes down to the visual style you want, the series you prefer, and how closely you want the finished car to echo a traditional American tire look. Since multiple makers cover the same size, it is worth comparing the exact sidewall treatment and wheel-width compatibility of the specific tire rather than assuming every 670-15 is identical in presentation.

For the 1948 Plymouth in 670-15, the Firestone Classic Bias Ply example shown is a blackwall tire rated at 1450 pounds at 32 psi, intended for 4.50 to 5.00-inch rims, and weighs 23 pounds. The Coker Classic Bias Ply example is a 2.75-inch whitewall rated at 1550 pounds at 32 psi, intended for 5.00 to 6.00-inch rims, and weighs 21 pounds.

Those differences make the comparison more about sidewall appearance and wheel compatibility than simple brand preference. A blackwall Firestone suits a more restrained look and narrower listed rim range, while the Coker Classic whitewall gives a more dressed-up postwar appearance and a broader listed rim-width range. Checking the wheel on the car is the smart next step before making that choice.

1948 Plymouth tires in 670-15 are listed across a rim-width range that runs from 4.50 to 6.00 inches depending on the specific tire. Firestone and US Royal examples fit 4.50 to 5.00-inch rims, while the Coker Classic example fits 5.00 to 6.00-inch rims. All of them mount on 15-inch wheels.

That means wheel diameter alone is not the whole story when selecting a tire for a 1948 Plymouth. If the car still has its original wheels, many buyers will be within the expected range, but a restored or altered car should have the actual wheel width measured before choosing among brands. That extra check helps avoid a mismatch between the tire and the wheel it must seat on.

The listed 1948 Plymouth 670-15 products do not show tube-type or tubeless markings in the size field, so tube choice should be confirmed against the exact tire and wheel combination you plan to run. With a postwar bias-ply application like this, wheel design and the specific tire's sidewall markings matter just as much as the nominal size.

That is especially important on original-style steel wheels, where restoration condition, rim sealing surface, and valve hardware can influence setup. Before mounting a set on a 1948 Plymouth, verify the specific tire's marking and assess the wheel itself rather than assuming every 670-15 bias-ply tire is installed the same way.

A 1948 Plymouth should be stored in a cool, dry, dark space away from direct sunlight, electric motors, welders, furnaces, and other ozone sources that can age rubber. Keep the tires properly inflated, avoid prolonged contact with standing moisture, and move the car periodically if possible. Bias-ply tires are more prone than radials to developing temporary flat-spotting after long static storage.

Collectors who park a 1948 Plymouth for months at a time often benefit from rolling the car occasionally or supporting it in a way that reduces constant load on one footprint. Good storage habits preserve the sidewalls, help the car drive more smoothly when it returns to the road, and protect the visual finish of blackwall or whitewall tires alike.

On a collector car like a 1948 Plymouth, tire age usually matters more than mileage. Many owners use the common practice of evaluating tires closely once they reach about five to seven years of age and treating around ten years as a serious replacement point regardless of tread depth. The DOT date code on the tire helps establish that timeline.

A lightly driven Plymouth can still age out a set of tires before the tread is worn, especially if the car spends time in sunlight or sits for long periods. Sidewall cracking, hardening, uneven wear, and a change in ride quality are all signs to inspect more closely. A collector car deserves age-based tire decisions, not just mileage-based ones.

Tires on a 1948 Plymouth should be checked before every drive, with a more thorough inspection before longer outings or tour events. Look for sidewall cracking, cuts, bulges, irregular tread wear, and pressure loss, and inspect the spare as well as the tires on the car. Valve stems and wheel sealing areas deserve attention too, especially on an older wheel and tire setup.

Regular inspection matters because a collector-era Plymouth may go from sitting still for weeks to running at road speed with little warning time for a problem to show itself. Catching aging rubber, a damaged sidewall, or a slow leak in the garage is far better than finding it after the car is loaded for a long drive.

A 1948 Plymouth Deluxe would have been fitted in the bias-ply era, and the applicable size here is 670-15. That aligns with the construction type expected for a mainstream American passenger car of the late 1940s, when radial passenger tires had not yet become the U.S. norm. The available replacements in this size remain true to that bias-ply format.

For a restoration, that means the most authentic path is usually staying with a 670-15 bias-ply tire and then choosing the sidewall treatment that matches the look you are after. If your car is being judged to a particular market, trim, or delivery standard, a Plymouth club or marque specialist can help narrow down whether blackwall or whitewall presentation is the more appropriate finishing detail.

Correct tire fitment matters on a 1948 Plymouth because judges and knowledgeable enthusiasts notice size, construction type, and sidewall appearance very quickly. A 670-15 bias-ply tire is in keeping with the car's period, while an obviously modern construction or an out-of-era sidewall treatment can change the car's stance and visual authenticity even if the wheel still physically accepts the tire.

That does not mean every event uses the same standard, but concours-minded owners usually benefit from treating tires as part of the restoration rather than an afterthought. Before finalizing a set for a show car, match the sidewall look to the car's presentation level and verify event-specific rules with a Plymouth club, judging guide, or marque expert familiar with postwar Chrysler products.

For the 1948 Plymouth in 670-15, the US Royal example shown is a wide whitewall bias-ply tire rated at 1450 pounds at 32 psi for 4.50 to 5.00-inch rims and weighs 22 pounds. The Universal Vintage Tire example is a blackwall bias-ply tire on a 15-inch rim and weighs 22 pounds. Both stay within the correct size and construction family for the car.

The practical difference is mostly visual, since one presents the classic whitewall look many restorers associate with late-1940s American cars and the other gives a plainer blackwall appearance. For a judged or highly period-aware restoration, that sidewall choice can be just as important as the brand itself. Wheel-width compatibility should still be confirmed before settling on the final tire.

1948 Plymouth tires in the listed 670-15 offerings are bias-ply designs, and no speed rating letters are shown for the available products here. Bias-ply tires can be used on public roads when they are correctly fitted, inflated, and in good condition, but they deliver a distinctly vintage driving feel compared with later radial designs. On a 1948 Plymouth, the car's own brakes, steering, suspension, and overall mechanical condition are often the bigger limits in real-world highway use.

A well-sorted Plymouth can certainly be enjoyed on secondary roads and moderate highway trips, but the smartest approach is to drive within the car's era and condition rather than expecting modern freeway behavior. Tire age, inflation, wheel condition, and alignment deserve close attention before any sustained run, especially on a car that may spend much of its life parked.

The available 670-15 products for 1948 Plymouth show load and pressure ratings of 1450 pounds at 32 psi on Firestone and US Royal examples, and 1550 pounds at 32 psi on a Coker Classic example. Those figures are tire ratings, not a universal instruction to inflate every 1948 Plymouth tire to the same running pressure. Factory vehicle recommendations and the exact tire selected both matter.

Use the Plymouth owner's literature or a trusted marque reference for the car's intended operating pressure, then compare that with the reproduction tire maker's published guidance for the exact tire you are running. Do not transfer one tire's rating to another brand by assumption, and do not use maximum load pressure as a blanket setting without confirming that it suits the vehicle.

Before a longer drive in a 1948 Plymouth, inspect each tire for sidewall cracking, cuts, bulges, uneven wear, and proper inflation, and make sure the spare is usable. Check valve stems, wheel hardware, and the condition of the wheel itself, especially if the car is running original or older restored rims. A postwar car also deserves a broader mechanical review that includes brakes, cooling, steering, and fluids.

That pre-drive routine is part of owning an older Plymouth responsibly. Tires may look fine at a glance but still show age-related issues once you inspect them closely, and a spare that has sat untouched for years is not much help on the roadside. A careful check before departure makes the drive more enjoyable and reduces the chance of a preventable interruption.