1955 BMW 502 Tires

The 1955 BMW 502 uses two primary tire sizes: 185R15 in radial construction and 640-15 in bias-ply construction. Both sizes are built for 15-inch rims, but they represent different tire formats and different ownership priorities, with one leaning toward modern radial sizing and the other toward a more traditional period-style bias-ply setup.

Choosing between them starts with the car’s current wheel setup and the kind of use planned for it. A restoration-minded owner may prefer the look and construction of 640-15, while a driver-focused owner may look more closely at 185R15. Either way, wheel width, overall dimensions, and clearance should be checked before changing construction or moving from one size format to the other.

The 1955 BMW 502 uses 15-inch rims with both of its primary tire sizes. That applies to the 185R15 radial fitment and the 640-15 bias-ply fitment, so the key distinction is not rim diameter but the tire construction and sizing system used on the car.

Rim diameter alone is only part of the fitment picture. Before selecting tires, it is worth confirming the actual wheel width on the car, especially if the BMW has been restored, modified, or fitted with replacement wheels over the years. A 15-inch wheel can still vary in width, and that affects how comfortably a given radial or bias-ply tire matches the wheel.

The 1955 BMW 502 Base uses the same two fitment paths found on the model overall: 185R15 in radial construction and 640-15 in bias-ply construction. Both are 15-inch applications, so the sub-model does not introduce a separate wheel diameter or a unique tire size requirement.

That consistency makes the decision more about tire type than about chasing a rare sub-model-specific size. The owner can focus on whether the car should keep a traditional bias-ply look or move toward a radial setup. It still helps to inspect the wheels currently on the car, since wheel replacement or long-ago modifications can affect which tire works best.

640-15 is a bias-ply tire size for the 1955 BMW 502. It uses the older numeric sizing format and is the traditional construction choice for this application, making it especially relevant for buyers who want a period-style tire with classic blackwall or whitewall presentation.

That matters because a bias-ply tire is not just a different construction label; it also shapes the look and setup of the car. Anyone moving away from 640-15 should confirm wheel width, tire dimensions, and clearance rather than assuming that a radial alternative behaves the same on the existing wheels. The construction decision should match both the vehicle’s appearance goals and road use.

Radial equivalents for 640-15 include 175R15 as the 80-series metric radial option, P175/75R15 as the 75-series P-metric radial option, and P185/70R15 as the 70-series P-metric radial option. Each of those alternatives stays in a 15-inch format while using a more modern radial sizing convention than the original numeric bias-ply size.

Those sizes are useful comparison points, but they should not be treated as automatic substitutes. A recommended rim-width range of 5 to 6 inches applies to the equivalents, and the car’s wheel width, tire dimensions, and available clearance still need to be checked. That is especially important on a collector sedan where wheel changes or suspension wear may affect final fitment.

A conversion from 640-15 bias-ply to a radial alternative starts with the basics: confirm the wheel diameter is still 15 inches, verify the actual wheel width, and compare the intended radial size carefully. For this BMW 502, the radial-equivalent path from 640-15 includes 175R15, P175/75R15, and P185/70R15, each with its own sizing convention.

The next checks are all vehicle-specific. Steering clearance, fender clearance, suspension condition, and the car’s current ride height can all influence whether a radial alternative is a sensible match. It is also worth deciding whether the goal is a more traditional appearance or a more modern driving setup, since changing construction can alter the character of the car even when rim diameter stays the same.

Start with the tire path that best matches the car: 640-15 if the goal is a traditional bias-ply presentation, or 185R15 if a radial setup is preferred. Both use 15-inch rims, but they differ in construction, sizing format, available sidewall treatments, and the wheel-width ranges that appear across the available products.

After size and construction are settled, compare the details that shape how the car will look and be used. Sidewall style, tire series, brand, rim-width compatibility, and load figures where stated can all matter. A BMW 502 that is shown and driven occasionally may call for a different choice than one prepared for regular touring, even within the same primary fitment.

The 1955 BMW 502 has a broad range of sidewall styles available across its two primary tire sizes. Depending on the tire chosen, options include blackwall, narrow whitewall, wide whitewall, and redline, with those styles spread across both the 640-15 bias-ply selection and the 185R15 radial selection.

That variety makes sidewall choice an important part of the buying decision rather than a minor detail. A wide whitewall or narrow whitewall can reinforce a formal mid-1950s presentation, while blackwall or redline can shift the look in a different direction. Since sidewall treatment does not override fitment, it should be chosen only after confirming the correct size and construction path.

Tires for the 1955 BMW 502 are available from several brands, including Michelin, Avon, Firestone, BFGoodrich, Excelsior, Coker Classic, and Universal Vintage Tire. Those brands span both of the car’s primary fitments, with radial offerings in 185R15 and bias-ply offerings in 640-15.

Brand matters mainly as part of a broader comparison, not as a shortcut to the right answer. The better approach is to narrow the choice by size, construction, sidewall style, and tire series first, then compare brand-specific options within that fitment. That keeps the selection tied to the BMW’s needs rather than choosing a brand before confirming the tire format.

A period-style 1955 BMW 502 usually starts with the 640-15 bias-ply size, since it preserves the traditional numeric format and opens the door to blackwall, narrow whitewall, and wide whitewall presentations. That makes it the natural fitment path for owners who want the car to retain a distinctly mid-1950s luxury-sedan character.

Appearance goals should still be balanced with the way the car will be used. A carefully driven show car may point toward one bias-ply style, while a regularly toured car may lead the owner to compare radial alternatives more closely. If exact originality matters beyond general period style, marque references and restoration records are worth consulting before settling on a sidewall treatment.

Tire construction changes more than ride and handling; it also changes how a restored 1955 BMW 502 presents visually. A 640-15 bias-ply keeps the car in a traditional vintage format, while a 185R15 radial introduces a more modern tire designation and a different range of sidewall choices, including redline and narrow whitewall options.

That difference becomes noticeable on a formal 1950s BMW where wheel and tire proportions contribute heavily to the overall look. Buyers who want a restoration-oriented appearance usually begin by choosing the correct size and construction family first, then selecting the sidewall style that best matches the car’s finish, trim, and intended presentation on the road or show field.

Yes, modifications can affect tire fitment on a 1955 BMW 502 even when the tire size itself appears correct. Changes such as replacement wheels, altered wheel width, suspension work, ride-height changes, or body repairs can influence how either a 640-15 bias-ply or 185R15 radial sits within the wheel opening and steers at full lock.

A car with decades of ownership history should never be assumed to remain exactly as delivered. Measuring the actual wheel diameter and width, then checking clearance at the fenders and suspension, is a smart step before choosing tires. That is particularly important when considering a construction change, since a radial and a bias-ply do not always behave the same on the same setup.

Before road use, inspect the wheel condition, valve stems, lug hardware, and the general condition of the suspension and steering components. New tires on a 1955 BMW 502 should also be checked for proper inflation, visible clearance around the fenders and suspension, and any signs that the wheel width or tire construction choice does not suit the current setup.

A careful short test drive is a good follow-up after installation. Listen for rubbing, confirm the steering returns smoothly, and recheck air pressure once the tires have settled in. On an older collector car, fresh tires cannot compensate for worn chassis parts, so the rest of the running gear deserves the same attention as the new rubber.

Tires on a collector 1955 BMW 502 should be maintained with regular pressure checks, visual inspections, and attention to age as well as tread depth. Whether the car wears 640-15 bias-ply tires or 185R15 radials, low annual mileage does not prevent rubber from aging, drying, or developing cracks, flat spotting, or air loss over time.

Storage conditions matter almost as much as mileage on a collector sedan. Keeping the car away from prolonged sunlight, excess heat, moisture, and ozone sources helps preserve the tires between drives. It is also wise to inspect sidewalls and tread before every outing, especially before a longer trip, because long-stored tires can deteriorate even when they still look presentable at first glance.