Plymouth P4 Tires

The Plymouth P4 uses two listed tire sizes for 1937: 600-16 and 650-16. Both sizes are built around a 16-inch rim diameter, but they represent different nominal section widths, with 600-16 corresponding to about 6.00 inches wide and 650-16 to about 6.50 inches wide. Product coverage for 600-16 is generally centered on 4.00 to 4.50 inch rim widths, while 650-16 is generally centered on 4.50 to 5.00 inch rim widths.

That means the correct tire for a Plymouth P4 is not determined by year alone, since both sizes appear in 1937. Check the existing tire size, measure the wheel width if needed, and compare the wheel setup against original references for your exact car. That will help you decide whether you need a narrower passenger-style fitment or the larger-width alternative.

On a Plymouth P4, 600-16 is an older numeric bias-ply size. The 600 indicates a nominal 6.00-inch section width, written without the decimal point, and the 16 is the rim diameter in inches. In the available Plymouth P4 products, this size is consistently associated with 16-inch wheels and is commonly matched to rims around 4.00 to 4.50 inches wide.

That code helps you separate width from wheel diameter, but it still does not tell you whether 600-16 or 650-16 is correct for your particular Plymouth P4. Use the size stamped on the tire or compare the wheel width and the car's existing setup before choosing. If your goal is a period-correct ride and appearance, stay with the original numeric bias-ply sizing rather than treating the numbers as a modern radial equivalent.

A 1937 Plymouth P4 can show both 600-16 and 650-16 because the model year includes more than one fitment within the same 16-inch wheel diameter. The difference is not a switch from one wheel diameter to another; it is a variation in tire width and the wheel setup that supports it. That is why the same year can carry either a narrower or wider numeric bias-ply size.

When a single Plymouth P4 year shows multiple sizes, the practical answer is to identify the exact wheel and configuration on the car rather than relying only on the model year. Existing wheel width, surviving old tires, and marque reference material are the best clues. That extra verification matters especially on restored cars, where wheels may have been changed decades ago.

Most Plymouth P4 tire options in 600-16 and 650-16 are period-style bias-ply products, and that style typically uses tube-type construction on vintage wheels. The available fitments for Plymouth P4 are overwhelmingly bias-ply, and tube use is the normal approach for these older numeric sizes. Even where a utility-oriented product may note tubeless construction, that does not automatically mean an original Plymouth wheel should be run without a tube.

For a restoration-minded Plymouth P4 owner, the safest approach is to match the tire to the wheel design and use tubes when the wheel and tire combination calls for them. Wheel condition, bead-seat design, and intended driving use all matter. If the car still has its original-style rims, tube-type installation is generally the correct vintage practice.

The right size for a 1937 Plymouth P4 starts with confirming whether the car uses 600-16 or 650-16. Both are legitimate 16-inch Plymouth P4 fitments for that year, but they differ in nominal width and commonly pair with different rim-width ranges. A car fitted with 4.00 to 4.50 inch rims will generally align with 600-16, while 4.50 to 5.00 inch rims generally align with 650-16.

Start by checking the size on the old tires if they are still present, then inspect the wheel dimensions and compare them with original references for your exact Plymouth P4. That method is more reliable than choosing by appearance alone. It also helps prevent a restoration problem where a wider tire is mounted to a wheel that was intended for the narrower size.

Plymouth P4 tires are offered in blackwall, wide whitewall, and double-whitewall styles, depending on size and series. The broadest selection appears in blackwall, while wide whitewall options are available in both 600-16 and 650-16, and double-whitewall choices appear in 600-16. Those choices allow owners to tune the car toward a more understated factory-type look or a more decorative period presentation.

For a Plymouth P4 restoration, sidewall style should match the character of the build as much as the size itself. A blackwall often suits a more conservative pre-war appearance, while wide whitewalls can emphasize a more formal or show-oriented finish. Decide on the visual goal only after the correct size has been settled, since style should never override fitment.

Plymouth P4 tires are available from a wide range of brands, including BFGoodrich, Coker Classic, Avon, Firestone, Ford Script, Excelsior, Lester, Goodyear, STA, Camac, Garfield, and Tornel. Those brands span traditional passenger-car bias-ply offerings, restoration-focused lines, and more utility-oriented truck or military tread patterns. The range is broad enough that a Plymouth P4 owner can choose by appearance, tread style, and intended use once the correct size is confirmed.

That variety makes brand choice a secondary decision after fitment and wheel setup. If your Plymouth P4 is being restored for period-correct appearance, compare sidewall style and series character first. If the car is intended for a more utilitarian purpose, be careful not to substitute a truck-style tread merely because it shares the same size.

Plymouth P4 tires appear in several distinct series, including Silvertown Classic Bias Ply, Coker Classic Bias Ply, Firestone Classic Bias Ply, Deluxe All-Weather, Ford Script, Lester Classic Bias Ply, Excelsior Bias Ply, Tourist Crossply, Turbospeed Mk4, Traction Mileage, Military NDT, Firestone Classic Military, Firestone Classic Truck, NATO CJ110, Transport, Transport Highway, Super Traxion, Tornel Classic Truck, and Garfield Classic Bias Ply. Some are traditional passenger-car bias-ply lines, while others are military, highway commercial, or knobby truck-style patterns built around the same vintage sizes.

For most Plymouth P4 passenger-car restorations, the traditional bias-ply passenger series will look and behave more like an original-era fitment than military NDT or truck tread options. The more aggressive utility patterns may suit specialty builds, but they change the character of the car visually and functionally. Treat the series name as a clue to intended use, not just styling.

A Plymouth P4 should be stored in a cool, dry, dark space with the tires kept away from sunlight, ozone sources, and standing moisture. Clean concrete is better than damp ground, and long-term contact with petroleum products should be avoided. For a pre-war car on bias-ply tires, consistent storage conditions matter because the carcass and sidewall are more vulnerable to age-related deterioration than a modern daily-driver tire.

If the Plymouth P4 will sit for extended periods, keep the tires inflated to the appropriate operating pressure for their size and move the car occasionally to avoid prolonged flat spotting. Many owners also reduce sustained load with jack stands placed correctly under the chassis, while still supporting the axle as needed. The goal is to preserve both the tire shape and the wheel integrity.

Tires on a Plymouth P4 should be inspected before each drive and given a more careful review several times through the season. A proper inspection includes checking inflation, sidewall cracking, tread separation, bead condition, valve stems, and any signs that the tire is shifting on the rim. On a low-use collector car, deterioration often comes from age and storage rather than mileage alone.

That routine is especially important with older-style bias-ply Plymouth P4 tires because many collector cars spend long periods parked. Catching a crack, bulge, or tube-related issue in the garage is far better than discovering it on the road. If anything about the tire's shape or condition looks unusual, have the assembly examined by a shop familiar with vintage tires and wheels.

A Plymouth P4 tire should be replaced when age, cracking, hardening, separation, impact damage, or persistent air loss appears, even if the tread still looks deep. Collector tires can age out long before they wear out, particularly on cars that are driven sparingly. The same rule applies with extra caution to any old period tire that may have spent decades in storage before installation.

For a Plymouth P4, tread depth alone is not a reliable guide because the car may see limited mileage but many years of storage cycles. Any uncertainty about structural condition deserves specialist inspection, especially with pre-war bias-ply construction. Replacing aged tires before visible failure is part of preserving both the car and the safety of everyone around it.

The Plymouth P4 is represented here by two original-style numeric bias-ply sizes for 1937: 600-16 and 650-16. Several passenger-oriented series are available in those sizes, including classic bias-ply and crossply lines, along with more specialized utility tread options in the same dimensions. That means the size format and general tire type are clear, but the exact original combination for a particular Plymouth P4 depends on the car's specific configuration and surviving reference material.

For an authenticity-focused Plymouth P4 restoration, use the car's original paperwork, wheel markings, factory literature, or established marque references to settle the exact size and style. Once that is known, choose the available series and sidewall treatment that best matches the era and presentation of the car. Restorers usually get the best result by deciding size first, then sidewall style, then brand or series.

Correct tire fitment can absolutely affect how a Plymouth P4 is judged and how seriously a restoration is taken. Size, sidewall treatment, stance, and tread character all influence whether the car presents as an authentic pre-war Plymouth or as a visually altered restoration. Even when the wheel diameter is correct, the wrong width or an obviously non-passenger tread can change the car's appearance substantially.

For a Plymouth P4 intended for concours, club judging, or top-tier resale, tire details deserve the same care as paint, trim, and upholstery. Marque clubs, period photos, and factory reference material are the best standards when deciding between blackwall, whitewall, and the two listed sizes. Small differences in tire presentation often stand out immediately on pre-war cars.

Plymouth P4 tires are available in blackwall, wide whitewall, and double-whitewall styles, though double-whitewall appears in the 600-16 offerings rather than across both sizes. Any of those can create a period look, but they do not project the same character. Blackwall is usually the more restrained and workmanlike presentation, while wide whitewall gives a more dressed-up pre-war appearance.

The correct choice for a Plymouth P4 restoration depends on how the individual car was equipped and how closely you want to match a specific historical presentation. Original photos, sales literature, and club references are worth consulting before settling on sidewall treatment. Once style is chosen, make sure it is available in the exact size your car requires rather than forcing a style onto the wrong fitment.

A properly selected and properly installed vintage-style tire can be suitable for driving a Plymouth P4 on public roads, but that answer depends on the entire condition of the car, not the tire alone. The available Plymouth P4 sizes are primarily bias-ply designs, and they should be treated as period-correct tires with period-correct handling characteristics. Steering response, braking feel, and stability will not mimic a modern radial-equipped car.

Safe road use starts with matching the exact size to the wheel, ensuring the tire and tube arrangement is appropriate, and verifying that the Plymouth P4's suspension, steering, and brakes are all in sound condition. Drivers should also respect the limitations of an older chassis and tire design. A conservative pace and smooth inputs are part of using a pre-war car responsibly.

Before driving a Plymouth P4, check tire pressure, visible sidewall condition, tread integrity, valve stems, wheel fasteners, and any sign of tube or bead trouble. Because the Plymouth P4 uses older-style bias-ply fitments, even minor changes in inflation or sidewall appearance deserve attention. It is also wise to look at brake response, steering free play, and the overall stance of the car before setting off.

That pre-drive routine matters more on a collector Plymouth P4 than on a modern car because age-related issues can appear after long storage even without recent mileage. If the car has been sitting, roll it forward and back and recheck the tires once they have flexed slightly. A few minutes in the garage can prevent damage to hard-to-replace wheels, tubes, and bodywork.

A Plymouth P4 fitted with original-type bias-ply tires should be driven at moderate, conservative speeds consistent with pre-war chassis design and the condition of the car. Even when the tire is new, the overall driving system includes older suspension geometry, manual steering, vintage braking performance, and a much taller sidewall than modern drivers are used to. The right speed is the speed at which the car remains settled, predictable, and mechanically comfortable.

In practice, that means avoiding the temptation to drive a Plymouth P4 like a modern highway car simply because the engine will do it. Build speed gradually, watch how the car tracks, and back off if steering feel, vibration, or braking confidence changes. Long-distance cruising is best approached only after the full car has proven itself in shorter local drives.