1966 AC Cobra Tires

The 1966 AC Cobra uses two primary tire sizes: 640-15 and 670-15. Both are bias-ply sizes for 15-inch rims, and both are associated with the Cobra Base configuration, so there is not a single universal size choice without checking the car’s actual setup.

The practical next step is to inspect the tires currently on the car and confirm the wheel dimensions before ordering replacements. Many Cobras and Cobra-based builds have seen changes over time, so choosing between 640-15 and 670-15 should be tied to the wheel width, the stance you want to preserve, and the clearance available at full steering lock and suspension movement.

The 1966 AC Cobra tire fitments covered here are built around a 15-inch rim diameter. Both primary sizes, 640-15 and 670-15, share that same 15-inch rim diameter, which keeps wheel diameter straightforward even though the car can use more than one tire size.

Rim diameter is only part of the fitment picture, so it is still important to check actual wheel width before selecting a tire. Some available products in these sizes are intended for narrower rims, while some radial-equivalent paths call for specific width ranges. Confirming the wheel itself first helps prevent a mismatch between the tire you choose and the hardware already on the car.

The 1966 AC Cobra is associated with both 640-15 and 670-15 bias-ply tire sizes, which means owners may encounter either size when replacing tires. Since both sizes appear under the same covered sub-model, the difference is less about trim naming and more about the wheel-and-tire setup actually on the individual car.

That matters because a Cobra may have been maintained, restored, or altered around one size or the other over the years. Rather than assuming the larger or smaller size belongs on every car, compare the existing tires, confirm wheel width, and make sure the replacement preserves proper clearance and the visual balance you want from the car’s 15-inch fitment.

For the 1966 AC Cobra, 640-15 is a bias-ply primary tire size. It is part of the car’s vintage fitment vocabulary and is available in traditional bias-ply form across several brand and sidewall combinations rather than as a primary radial fitment.

Owners considering a change in construction should keep the original-size role separate from the radial-alternative discussion. A bias-ply 640-15 preserves the traditional sizing format and appearance, while radial equivalents need to be evaluated as alternatives by checking wheel width, overall fit on the car, and whether the goal is restoration-oriented presentation or more modern road manners.

Radial equivalents for 670-15 include 195R15 as an 80-series metric radial, P205/75R15 as a 75-series P-metric radial, P215/70R15 as a 70-series P-metric radial, and 670R15 as a bias-look radial. These alternatives keep the 15-inch rim diameter while offering different sizing conventions and profile families.

The recommended rim-width range tied to these 670-15 equivalents is 5-7 inches, which makes wheel measurement especially important before choosing one. A radial equivalent can be a useful alternative, but it still needs to be checked against the Cobra’s wheel width, available clearance, and the overall look you want, since equivalent does not mean automatic interchangeability.

Start by identifying whether the car is currently using 640-15 or 670-15, then match that size to the correct radial-equivalent group. For 640-15, the radial alternatives are 175R15, P175/75R15, and P185/70R15. For 670-15, the alternatives are 195R15, P205/75R15, P215/70R15, and 670R15.

After that, confirm wheel width, wheel diameter, and clearance at the fenders and steering stops. A 640-15 equivalent is tied to a 5-6 inch rim-width range, while 670-15 equivalents use 5-7 inches. It is also wise to inspect suspension condition and alignment before the switch so the car’s setup supports the new tire construction rather than working against it.

The first decision is confirming whether the car uses 640-15 or 670-15, since both sizes are associated with the 1966 AC Cobra and both are bias-ply fitments on 15-inch rims. After size is confirmed, the main factors become construction choice, sidewall treatment, tire series, and how closely you want to stay with a traditional period-style presentation.

A buyer comparing options should also look at wheel-width suitability, load figures where they are stated, and whether the car is driven mainly for shows, touring, or occasional road use. That approach helps narrow the field without assuming every tire in the correct nominal size will suit the same wheel setup or produce the same visual effect.

Tires for the 1966 AC Cobra are available in blackwall, narrow whitewall, and wide whitewall styles across the covered 640-15 and 670-15 sizes. That gives owners a broad visual range, from a simple competition-oriented blackwall look to a brighter period-style presentation with whitewall detail.

Sidewall style should be chosen with the car’s finished appearance in mind rather than as a purely cosmetic afterthought. A blackwall tends to keep the look understated and functional, while narrow and wide whitewalls make a stronger styling statement. Since sidewall treatments vary by brand and series, it helps to compare them only after the correct tire size has been confirmed.

Available 1966 AC Cobra tire options come from BFGoodrich, Firestone, Avon, Excelsior, US Royal, Universal Vintage Tire, Coker Classic, Goodyear, and STA. Those brands appear across the two primary bias-ply sizes, with the widest assortment concentrated in 670-15.

Brand choice should be considered alongside the specific tire series, sidewall style, and wheel-width requirements of the tire you are evaluating. Some owners will focus on a traditional blackwall or whitewall appearance, while others may be drawn to a particular vintage-style series. The best comparison is not brand alone, but the full combination of size, appearance, and fitment details.

A period-style starting point for a 1966 AC Cobra is one of its primary bias-ply sizes, either 640-15 or 670-15, depending on the wheel-and-tire setup already on the car. Staying with a bias-ply construction preserves the vintage sizing format and keeps the tire choice aligned with the Cobra’s 1960s character.

From there, the appearance decision moves to brand, tire series, and sidewall treatment rather than leaving the correct size behind. Exact originality can vary from car to car, especially on a vehicle as often restored or reconfigured as a Cobra, so owners pursuing highly specific authenticity should compare the tire choice against marque references and the individual car’s history.

On a restored 1966 AC Cobra, bias-ply construction keeps the most traditional visual character because it matches the vintage tire format associated with the car’s primary fitments. A radial equivalent can still be appropriate for some owners, but its sizing convention and overall presentation may shift the look away from a purely period-style bias-ply impression.

That difference matters most when the restoration goal is to preserve the car’s stance and era-correct visual language rather than simply fill the wheel opening. Sidewall treatment also changes the final impression, especially when comparing blackwall, narrow whitewall, and wide whitewall options. Construction and sidewall should be chosen together so the finished car looks intentional instead of mixed in theme.

Yes. A 1966 AC Cobra may use 640-15 or 670-15 on 15-inch rims, and any change to wheel width, wheel offset, suspension height, or body clearance can alter how either size fits the car. Even when the tire size itself is correct, modifications can change available space at the fenders or steering components.

That is why an owner should inspect the actual wheel-and-suspension setup instead of relying on the model name alone. If the Cobra has aftermarket wheels, revised springs, or body changes, verify clearance through full steering travel and suspension movement. Those checks become even more important when considering a radial equivalent rather than staying with the original bias-ply construction.

Before road use, inspect the wheel condition, lug hardware, tire pressure, and the basic seating of the new tires on the rims. It is also smart to look over suspension and steering components, since a 1966 AC Cobra places a premium on stable, predictable response and tire fitment is only one part of that system.

A short check for fender clearance, steering-lock clearance, and any sign of rubbing should be part of the first drive. After the initial miles, recheck inflation pressure and look for unusual wear or contact marks. Collector cars that spend long periods parked also benefit from periodic inspection for air loss, sidewall aging, and any change in stance that might point to a setup issue.

Collector-car tires in 640-15 or 670-15 size should be kept properly inflated, visually inspected on a regular basis, and monitored for cracking, cuts, bulges, uneven wear, or slow air loss. Because many Cobras see intermittent use, condition matters just as much as tread depth when judging whether the tires are still ready for road duty.

Storage habits make a difference as well. Keeping the car away from prolonged sunlight, moisture, and ozone sources helps preserve sidewall condition over time. Before any longer drive, inspect the tires cold and confirm that the wheel hardware and suspension still support the tire setup you are using, especially if the car has been parked for extended periods between outings.