1966 BMW 2600 Series Tires

The 1966 BMW 2600 Series uses two primary tire sizes: 185R15 in radial construction and 640-15 in bias-ply construction. Both are 15-inch fitments, so the correct choice is not just about diameter but about which construction and sizing system the car is set up to use.

A car that already wears radial-friendly wheels may point you toward 185R15, while a more traditional setup may still use 640-15. Before selecting a tire, confirm the current wheel width, check the sidewall markings on the tires already on the car, and make sure any previous wheel or suspension changes have not altered the fitment requirements.

The 1966 BMW 2600 Series uses a 15-inch rim diameter with both of its primary tire sizes. That shared rim diameter applies whether the car is using the 185R15 radial format or the 640-15 bias-ply format.

Rim diameter is only the first check. Wheel width matters too, especially because the available 185R15 and 640-15 products do not all share the same rim-width specifications. Looking at the actual wheel on the car before changing size or construction helps prevent a mismatch between the tire you choose and the wheel that has to support it.

640-15 is a numeric bias-ply size. The 640 portion represents an approximate 6.40-inch nominal section width, while the 15 indicates a 15-inch rim diameter. On the 1966 BMW 2600 Series, it identifies the traditional bias-ply fitment path rather than a modern metric radial size.

That matters because a 640-15 tire affects both the look and the wheel requirements of the car. A buyer comparing it to a radial should not treat the size code as interchangeable with modern metric sizing. The smarter next step is to confirm the wheel width and decide whether the goal is to preserve a vintage bias-ply presentation or move toward a radial alternative.

On the 1966 BMW 2600 Series, 640-15 is a bias-ply tire size. It is the traditional numeric format used for vintage fitments, while the radial fitment path for this model is 185R15.

Knowing that difference helps frame the rest of the decision. Keeping 640-15 maintains the bias-ply size format and opens up blackwall, narrow whitewall, and wide whitewall choices. Moving away from it means checking not only radial alternatives, but also wheel-width suitability and how the overall tire presentation fits the way the car is being restored, displayed, or driven.

Radial equivalents for 640-15 include 175R15, P175/75R15, and P185/70R15. Those represent three different equivalent types: an 80-series metric radial, a 75-series P-metric radial, and a 70-series P-metric radial, all tied to the 640-15 bias-ply size.

Each of those alternatives uses a different sizing convention, so they should be treated as comparison options rather than automatic substitutes. A 5-6 inch rim-width range is associated with these equivalents, and the final choice should be checked against the car’s wheel width, overall tire dimensions, and clearance at the fenders and steering components before changing from bias-ply to radial.

The 1966 BMW 2600 Series supports both directions, with 640-15 as the bias-ply fitment and 185R15 as the radial fitment. The right choice depends on whether the priority is a more traditional period-style appearance or a radial-based setup in a classic Euro-metric format.

A bias-ply choice keeps the vintage sizing language and opens up several whitewall and blackwall options, while a radial setup broadens the field of European-style touring tires and redline alternatives. The decision should be made around the wheels on the car, the visual result you want, and whether the suspension and clearances have already been sorted around one construction type or the other.

Start with the basics: confirm that the car is using the 185R15 radial fitment path and that the wheels are appropriate for the product being considered. Within that size, the available choices vary by brand, tire series, sidewall style, load specification, and rim-width range.

The practical decision usually comes down to how the car will be presented and driven. A Michelin XVS gives a classic European touring flavor, while Coker Classic and Universal Sport add redline or blackwall options. It also helps to compare wheel-width requirements product by product, since one 185R15 radial does not necessarily share exactly the same wheel preference as another.

The 1966 BMW 2600 Series has a broad range of sidewall treatments across its two tire sizes. Available styles include blackwall, narrow whitewall, wide whitewall, and redline, depending on whether you are looking at the 185R15 radial selection or the 640-15 bias-ply selection.

That variety matters because sidewall style changes the entire visual character of the car even when rim diameter stays the same. A redline radial gives a sportier period-inspired look, while whitewall bias-ply tires create a more formal vintage presentation. The best choice depends on whether the car is being restored, shown, or driven with a particular era-specific appearance in mind.

Tires for the 1966 BMW 2600 Series are available from Coker Classic, Michelin, Avon, Universal Vintage Tire, BFGoodrich, Firestone, and Excelsior. Those brands span both the 185R15 radial fitment and the 640-15 bias-ply fitment, giving buyers several ways to approach the car.

Brand choice should be part of a larger comparison rather than the only deciding factor. It makes sense to narrow the search by correct size and construction first, then compare sidewall style, tire series, rim-width suitability, and any load information that is relevant to the car’s intended use. That approach keeps appearance and fitment aligned instead of choosing by name alone.

A period-style 1966 BMW 2600 Series can be approached in two distinct ways. The 640-15 bias-ply size supports a traditional vintage presentation, while the 185R15 radial size keeps the car in a classic European radial format that also suits the era well.

The better choice depends on how strictly the finished car is being interpreted. Bias-ply tires usually support a more formal, earlier look, while 185R15 radials can preserve a proper European touring character with a different roadgoing feel. If exact originality matters, compare your tire choice with marque references, period photos, and other vehicle-specific historical materials before deciding.

Tire construction changes more than ride and handling on a restored 1966 BMW 2600 Series; it also changes the car’s visual stance and sidewall character. A 640-15 bias-ply setup gives a more traditional vintage look, while a 185R15 radial reads as a later-style European road tire presentation.

Sidewall treatment then refines that effect further. Wide whitewall, narrow whitewall, blackwall, and redline options can each shift the personality of the car even within the correct size family. For a restoration-oriented build, it helps to decide first whether the car should look formal, sporting, or understated, then match construction and sidewall style to that target.

Yes. Any wheel, suspension, or body change can affect tire fitment on a 1966 BMW 2600 Series, even when the tire size sounds correct on paper. Changes in wheel width, offset, ride height, or steering geometry can alter how a 185R15 or 640-15 tire sits and clears the car.

That is especially important on an older car that may have had decades of repairs or upgrades. A tire should be chosen around the actual wheel and chassis setup now on the vehicle, not just the expected factory-era arrangement. Checking inner and outer clearance at full steering lock is a smart step before settling on a new set.

Before road use, inspect the wheels for correct diameter and visible damage, confirm lug hardware condition, and set inflation to the tire maker’s guidance for the chosen product. It also makes sense to verify that the tires clear the suspension, fenders, and steering components without rubbing.

A 1966 BMW 2600 Series may have been stored, restored, or modified, so a broader check is worthwhile. Look over wheel bearings, alignment condition, brake function, and any signs of suspension wear that could affect how the new tires track. A short local test drive followed by a second inspection can catch issues before longer road use.

Collector-car tires on a 1966 BMW 2600 Series should be kept clean, properly inflated, and inspected regularly for cracking, flat spotting, cuts, bulges, and slow air loss. Cars that are driven infrequently need attention even when tread wear is minimal, because age and storage conditions matter as much as mileage.

Storage habits have a direct effect on long-term tire condition. Keeping the car away from prolonged sunlight, ozone sources, and damp conditions helps preserve both sidewalls and overall casing health. It also helps to move the car periodically or adjust its resting position so one section of the tire is not carrying the same load for months at a time.