1950 Plymouth Suburban Tires

The 1950 Plymouth Suburban uses two primary tire sizes: 640-15 and 670-15. Both are vintage numeric bias-ply sizes intended for 15-inch wheels, so the main fitment question is not radial versus bias-ply at the factory-style size level, but which of those two bias-ply sizes matches the wheel and current setup on the car.

A car that has been restored, serviced over many years, or fitted with replacement wheels may not still have the same wheel width it once used. Checking the size stamped on the current tire, measuring wheel width, and confirming body and steering clearance will help narrow the choice before selecting sidewall style or considering a radial equivalent.

The 1950 Plymouth Suburban uses a 15-inch rim with its primary tire fitments. Both 640-15 and 670-15 are built around that same rim diameter, which keeps the basic wheel diameter question simple even though the vehicle can use more than one tire size within that 15-inch family.

Rim diameter is only part of the picture on a vintage wagon. Wheel width still matters, especially when comparing different bias-ply products or looking at radial equivalents that carry their own recommended rim-width ranges. Confirming the actual wheel on the car is important before assuming that any 15-inch tire in the right nominal size will suit the existing setup.

Both 640-15 and 670-15 are numeric bias-ply sizes. The first number is the nominal section width expressed in an older inch-based format, so 640 represents about 6.40 inches and 670 represents about 6.70 inches, while the 15 indicates the wheel diameter in inches.

That older sizing system matters because it does not read like modern metric radial sizes. A buyer comparing period-style tires, whitewall treatments, or radial alternatives should recognize that these are vintage bias-ply measurements first, then compare wheel width, overall presentation, and the actual space available in the wheel opening before making a substitution.

For the 1950 Plymouth Suburban, both 640-15 and 670-15 are primary bias-ply tire sizes. That means the original fitment family for this vehicle is centered on vintage bias-ply construction rather than a modern radial size, even though radial equivalents are available for buyers who want to compare alternatives.

Bias-ply construction supports a more traditional appearance and period-style presentation, which matters on an early postwar wagon. A move to radial construction changes the decision from simply choosing a tire in the original format to verifying rim-width suitability, checking clearance, and deciding whether road-use priorities outweigh keeping the tire construction visually in line with the car's era.

A 640-15 can be compared with 175R15, P175/75R15, and P185/70R15. A 670-15 can be compared with 195R15, P205/75R15, P215/70R15, and 670R15, with that last option serving as a bias-look radial equivalent rather than a standard metric or P-metric radial format.

Those equivalents give the 1950 Plymouth Suburban owner several ways to approach a radial conversion, from a conventional Euro-metric radial to P-metric sizes and a bias-look radial in the 670-15 family. Each option should still be checked against wheel width, tire dimensions, and clearance at full steering lock rather than treated as an automatic interchange.

That choice depends on how the 1950 Plymouth Suburban is being used and how closely the owner wants to retain a traditional presentation. Bias-ply tires keep the vehicle in its original fitment style, while radial equivalents provide an alternative sizing path for buyers who are evaluating different road-use priorities.

A restoration-oriented car often stays with bias-ply construction because the sidewall profile and overall look suit the period. A driver-focused car may lead the owner to consider radial equivalents, but the decision should include wheel-width confirmation, clearance checks, and a look at whether the car still has stock suspension and wheel specifications before making the switch.

Start by confirming whether the car should use 640-15 or 670-15 on its current 15-inch wheels. After that, the important comparisons are construction type, sidewall style, rim-width compatibility, load capacity where shown, and whether the goal is a traditional bias-ply presentation or a move toward a radial-equivalent setup.

The right choice depends on how the wagon will be used and how it is meant to look. A car aimed at period-style appearance may lean toward a blackwall or whitewall bias-ply in the correct size family, while a car intended for more road time may lead the owner to compare equivalent radial formats after checking wheel width and overall fitment carefully.

Tires for the 1950 Plymouth Suburban are available in blackwall, narrow whitewall, and wide whitewall styles. Those sidewall treatments appear across both 640-15 and 670-15 offerings, although the wider selection is in 670-15, where several brands and tire series give buyers more visual choices within the correct vintage size family.

That makes sidewall style one of the biggest appearance decisions on this vehicle. Blackwalls create a simpler, more utilitarian look, while narrow and wide whitewalls shift the visual character toward a more dressed-up postwar presentation. The best starting point is to match the tire style to the car's restoration direction rather than choosing purely by availability.

The 1950 Plymouth Suburban has tire options from BFGoodrich, Firestone, Avon, Excelsior, US Royal, Universal Vintage Tire, Goodyear, Coker Classic, and STA. Brand availability varies by size, with 670-15 offering the broader assortment across multiple bias-ply series and sidewall treatments.

Choosing among brands is less about ranking one above another and more about finding the right combination of size, series, sidewall appearance, and wheel compatibility. A buyer looking for a wide whitewall has different visual priorities than someone wanting a plain blackwall or a more specialized commercial-style tire, so the product details are worth comparing closely within the correct size.

A period-style 1950 Plymouth Suburban usually starts with one of its original bias-ply size families, either 640-15 or 670-15, on a 15-inch rim. From there, the most important decisions are sidewall presentation and tire series, since blackwall, narrow whitewall, and wide whitewall options each create a different postwar visual character.

A buyer aiming for historical accuracy should use the tire size as the first filter, then compare sidewall styling against trusted Plymouth references, period photos, or marque-club guidance for the exact car. That approach helps keep the tire choice restoration-oriented without assuming that every available whitewall or brand treatment is automatically correct for every Suburban.

On a restored 1950 Plymouth Suburban, tire construction changes more than road feel. Bias-ply tires preserve the vintage format the car was designed around, and that usually supports the traditional sidewall shape and overall presentation collectors expect to see on an early postwar Plymouth wagon.

Radial equivalents can still be worth considering, especially when road use is part of the plan, but they should be viewed as an alternative rather than the same visual statement as a bias-ply tire. Owners balancing restoration style with drivability often compare construction and sidewall appearance together instead of treating size alone as the entire decision.

Yes, modifications can change tire fitment on a 1950 Plymouth Suburban even when the tire size looks correct on paper. Aftermarket wheels, altered wheel width, suspension changes, ride-height changes, or bodywork differences can all affect how a 640-15, 670-15, or radial-equivalent alternative sits and clears the vehicle.

A vintage wagon that has been changed over time should be checked at the wheel rather than judged by catalog size alone. Measuring actual wheel width, confirming 15-inch diameter, and checking fender and steering clearance are especially important before moving from bias-ply to radial, since construction and profile changes can alter how the tire occupies space.

Before driving a 1950 Plymouth Suburban on new tires, inspect wheel condition, wheel diameter, lug hardware, and inflation pressure, then confirm there is no contact at the fenders, suspension, or steering components. It is also worth checking for uneven ride height or worn front-end parts that could affect how the tires sit under the car.

A careful first road test should include low-speed turning and a look for rubbing marks after the car rolls and settles. On a collector vehicle, tire age and condition may have hidden other issues for years, so fresh tires are a good time to inspect alignment, wheel trueness, and any air loss before assuming the vehicle is ready for regular use.

Collector-car tires in 640-15 or 670-15 should be checked regularly for proper pressure, tread wear, cuts, bulges, and sidewall cracking. On a 1950 Plymouth Suburban that sees occasional use, visual inspection matters just as much as mileage because long storage periods can age tires even when the car is driven very little.

Good maintenance also includes storing the vehicle away from prolonged sunlight, moisture, and ozone sources, and moving it periodically so the tires do not remain loaded in one position for too long. Before any longer drive, a brief pressure check and walk-around inspection can catch problems early and help protect both ride quality and fitment.