1940 Plymouth Tire Fitment Guide

1940 Plymouth vehicles use three different tire sizes, and they are tied to specific models rather than shared across the full lineup. The Plymouth Deluxe uses 600-16 and 650-16 bias-ply tires, while the Plymouth Road King uses 550-16 bias-ply tires. All three sizes mount on 16-inch wheels, but the published rim-width ranges differ by size: 550-16 centers on 3.25 to 4.00 inches, 600-16 on 4.00 to 4.50 inches, and 650-16 on 4.50 to 5.00 inches where listed.

That means a 1940 Plymouth owner should identify the model first, then confirm the actual wheel width before settling on a tire. A Deluxe owner may be comparing two valid size paths within the model, while a Road King owner should stay within the narrower 550-16 range. Even though the wheel diameter is 16 inches across the board, the section width and wheel-width requirements are not interchangeable.

On a 1940 Plymouth, 600-16 is a traditional numeric bias-ply size. The first number represents the nominal section width class, and the 16 identifies the wheel diameter in inches. It is not a modern metric code, and it does not describe the tire in the same way a later radial size would. Within the 1940 Plymouth range, 600-16 applies to the Deluxe rather than the Road King.

A buyer looking at 600-16 should think in terms of prewar fitment practice, sidewall appearance, and wheel-width compatibility instead of trying to translate it directly into a modern passenger-car radial. If your Deluxe currently wears 16-inch wheels in the 4.00 to 4.50 inch range, 600-16 is one of the appropriate Plymouth-specific options to investigate further.

No, 1940 Plymouth models do not all use the same tire size. The Road King uses 550-16, while the Deluxe uses either 600-16 or 650-16 depending on the specific setup. All are bias-ply sizes for 16-inch wheels, but they are not one-size-fits-all across the make. The difference is meaningful because each size is associated with a different wheel-width range and a different visual footprint on the car.

That is why identifying the car as a Road King or Deluxe should happen before comparing whitewall styles or brands. If you are restoring a car with mixed parts or replacement wheels, measure the wheel and verify the model before assuming another 1940 Plymouth size will work. Plymouth shared engineering themes across the line, but tire sizing was still model-dependent.

1940 Plymouth tires are available in both blackwall and wide whitewall styles across the sizes used by the make. The 600-16 Deluxe size includes blackwall and wide whitewall options, the 650-16 Deluxe size also includes both, and the 550-16 Road King size can be found in blackwall and wide whitewall as well. That gives owners flexibility whether they want a restrained driver presentation or a more period-flavored visual statement.

For a 1940 Plymouth judged or restored with a strong factory-era look in mind, sidewall choice matters almost as much as size. Whitewalls often suit the visual language many collectors want from a prewar American car, while blackwalls can be the better match for a simpler, less ornate presentation. The right choice depends on how the individual car is being restored and how closely you want it to reflect its original market character.

Several brands cover 1940 Plymouth fitments. In 600-16, available brands include BFGoodrich, Coker Classic, Avon, and Firestone. In 650-16, the brands include BFGoodrich, Coker Classic, Firestone, and Garfield. In 550-16, the available brands include Excelsior, Avon, BFGoodrich, and Firestone. All of these offerings are bias-ply tires suited to the prewar Plymouth era rather than later radial conversions.

Brand choice on a 1940 Plymouth usually comes down to the combination of sidewall style, the exact size you need, and how closely you want the tire's appearance to align with your restoration goals. A Road King owner has a smaller size pool to choose from, while a Deluxe owner can compare multiple brands within two separate size groups. Once the correct size is settled, brand becomes a styling and presentation decision as much as a functional one.

Both 600-16 and 650-16 are 16-inch numeric bias-ply sizes used on the 1940 Plymouth Deluxe, but 650-16 is the wider size class. Their published wheel ranges also differ where available: 600-16 products center on 4.00 to 4.50 inch rims, while 650-16 products center on 4.50 to 5.00 inch rims. Sidewall choices are available in both sizes, including blackwalls and wide whitewalls, so the main distinction is not sidewall type but which Deluxe setup your car actually requires.

If your Deluxe still has its original-style wheels, confirming their width is the cleanest way to narrow the choice. A 600-16 usually suits the narrower of the two Deluxe wheel ranges, while 650-16 belongs with the wider one. Staying with the size group that matches the wheel keeps the car visually balanced and avoids guessing across two sizes that are both correct somewhere within the Deluxe family.

Rim-width requirements for 1940 Plymouth tires vary by size. Products in 550-16 list 3.25 to 4.00 inch rim widths, 600-16 products list 4.00 to 4.50 inch widths, and 650-16 products list 4.50 to 5.00 inch widths where that guidance is published. All three sizes fit 16-inch wheels, but the usable wheel width grows as the tire section width increases. That relationship matters on a prewar car because wheel and tire proportions are a major part of how the car drives and sits.

Measure the wheel or confirm its actual width before choosing among Plymouth sizes, especially on a car that may have had replacement wheels installed over the decades. Matching the tire to the correct wheel width helps preserve proper sidewall shape and keeps the fitment closer to what the chassis expects. Wheel diameter alone is not enough to sort out a 1940 Plymouth tire choice.

All 1940 Plymouth tire sizes in this group use a 16-inch wheel diameter, so there is shared diameter compatibility across the lineup. That does not mean every original wheel is suitable for every Plymouth size, because the published rim-width ranges are different for 550-16, 600-16, and 650-16. A Road King wheel setup belongs in a narrower range than a Deluxe using 650-16, and a Deluxe wheel suited to 650-16 is not the same target as one carrying 600-16.

If the car still has its original wheels, confirm their width before moving from one Plymouth size to another. This is especially important on Deluxe models, where both 600-16 and 650-16 appear in the fitment picture. Keeping the tire matched to the wheel's actual width is the safest way to preserve proper fit and avoid forcing a correct Plymouth size onto the wrong Plymouth wheel.

A 1940 Plymouth should be stored in a cool, dry, dark space away from direct sunlight, electric motors, welders, furnaces, and other ozone-producing equipment that can accelerate sidewall aging. Because these Plymouth fitments are bias-ply tires, long static storage can also increase flat-spotting compared with a modern radial. Clean floors, steady temperature, and keeping the tires out of standing moisture all help protect both the casing and the wheel area over time.

If the car will sit for extended periods, maintain inflation, move it periodically, or place it on stands when appropriate to reduce the chance of settled flat spots. Collectors who drive only occasionally should also keep the spare in the same protected environment. Good storage habits matter as much as tread depth on a low-use prewar Plymouth because age and environment usually end a collector tire's life before mileage does.

Tires on a 1940 Plymouth are usually judged more by age and condition than by miles driven. A useful collector-car rule is to begin evaluating them closely once they reach the five- to seven-year range and to treat the ten-year point as a serious replacement consideration regardless of remaining tread. The DOT date code on the tire sidewall is the starting point for that timeline, followed by the tire's actual condition in use and storage.

A lightly driven prewar Plymouth may look fine from a distance while still carrying hardened rubber, fine cracking, or age-related separation risk. Owners who show the car infrequently often assume low mileage equals long life, but storage history has just as much influence. If the tire's age is climbing, an inspection by a vintage-tire-savvy professional is a wise step before relying on the car for regular road use.

Tires on a 1940 Plymouth should be inspected before every drive and again before any longer outing. Look for sidewall cracking, cuts, bulges, uneven tread wear, embedded debris, and any sign that the tire is losing pressure between uses. On a bias-ply collector car, changes in shape or sidewall appearance deserve attention quickly because age-related issues can show up long before the tread is worn out.

A longer trip calls for a second round of checks that includes the spare, valve stems, and wheel condition. If the car has been parked for a while, roll it a short distance and recheck for flat spots or vibration before committing to highway speeds. Frequent inspection is inexpensive insurance on a 1940 Plymouth because tires are one of the few components that connect a prewar chassis to modern roads.

A 1940 Plymouth Deluxe would have originally been a bias-ply car, which matches the available 600-16 and 650-16 fitments used within the Deluxe line here. Those two sizes reflect prewar tire practice, and both are offered today in period-appropriate bias-ply construction with blackwall and wide whitewall choices. Original-equipment branding could vary by market and delivery history, so the most dependable anchor points are the correct size, the bias-ply construction, and an era-appropriate sidewall treatment.

For a restoration aiming at factory authenticity, start by confirming whether your individual Deluxe should be in 600-16 or 650-16 and then select the sidewall style that best matches the car's intended presentation. Factory literature, surviving unrestored examples, and Plymouth marque clubs are the right places to resolve market- or trim-specific details. Getting the construction and stance right usually matters more than chasing an assumed original brand name.

Correct tire fitment matters on a 1940 Plymouth because judges and knowledgeable enthusiasts notice size, construction, and sidewall style immediately. A prewar Plymouth shown for authenticity should look like a bias-ply car, and an incorrect size or an out-of-character sidewall treatment can change the car's stance enough to stand out. On a Road King, using a Deluxe-size tire would alter the visual proportion; on a Deluxe, choosing the wrong of its two size groups can do the same.

Owners preparing a show car should confirm the model first, then narrow the proper size and sidewall appearance before deciding among brands. Event standards are not always identical, so local judging guidelines and Plymouth marque organizations are the best authority for final authenticity calls. The closer the tire's construction and appearance are to the period, the more naturally the rest of the restoration tends to read.

Blackwall and wide whitewall tires for a 1940 Plymouth share the same basic bias-ply construction within a given size, but they create very different visual impressions. Blackwalls are offered in 550-16, 600-16, and 650-16, and wide whitewalls are also available across those same Plymouth sizes. The difference is primarily appearance rather than fitment, with the whitewall adding a more formal and visibly prewar presentation to the car's profile.

A restorer should choose between them by looking at the car's intended finish level and period character rather than assuming one is universally correct. Many prewar American cars look especially complete on a whitewall, while blackwalls can better suit a simpler or more understated restoration. Once the proper size is established, the sidewall treatment becomes one of the strongest styling decisions you will make on a 1940 Plymouth.

1940 Plymouth tires can be appropriate for highway use when they are the correct size, in sound condition, and operated within the speed capability marked on the tire. Among the sizes used here, one 600-16 product carries an H speed rating up to 130 mph, while one 550-16 product carries an L rating up to 75 mph; other products are traditional bias-ply offerings without that same modern-style speed-letter presentation. On a prewar Plymouth, the car's own braking, steering, suspension, and overall mechanical condition are usually more limiting than the tire at ordinary road speeds.

The practical question is not whether a 1940 Plymouth can reach highway speed, but whether the entire car is prepared to do so with stability and margin. Choose a tire whose condition and rating match your intended use, keep expectations aligned with prewar chassis behavior, and avoid treating vintage bias-ply tires like modern high-speed touring radials. Highway use is realistic when the car is sorted carefully and driven with period-correct restraint.

Inflation pressure on a 1940 Plymouth should start with the vehicle's factory recommendation and then be checked against the tire's own construction and rating. Among the available products, several 600-16 tires list 1400 pounds at 32 psi, several 650-16 tires list 1580 pounds at 32 psi, and one 550-16 Firestone lists 840 pounds at 32 psi. Those figures describe tire capability at a stated pressure, not a universal Plymouth setting to be copied from one size to another.

Use the correct size-specific guidance for the tire you select and avoid borrowing a pressure figure from another Plymouth size just because it also fits a 16-inch wheel. The owner's manual remains the right source for period vehicle recommendations, while the tire maker's specification tells you the tire's rated capacity and pressure relationship. Matching both pieces of information keeps the choice grounded in how the car and tire were intended to work together.

Before a longer drive in a 1940 Plymouth, inspect all four tires and the spare for cracking, cuts, bulges, tread damage, uneven wear, and signs of pressure loss. Confirm inflation when the tires are cold, examine the valve stems, and make sure the wheel fasteners and wheel condition are sound. Because these are prewar bias-ply applications, also pay attention to how the car feels in the first few miles after sitting, especially if it has been stored for a while.

That tire inspection should be part of a broader pre-drive routine that includes brakes, steering play, suspension condition, lights, fluids, and cooling system readiness. A 1940 Plymouth can be very enjoyable on secondary roads and moderate-distance outings, but confidence comes from treating the tires as one piece of an older mechanical system rather than the whole answer. A careful check before departure usually reveals problems while they are still easy to solve.