1965 Amphicar Tires

The 1965 Amphicar uses two primary tire sizes: 640-13 and 650-13. Both are bias-ply sizes built for 13-inch rims, and the Base sub-model is associated with both. That means the fitment question is less about trim level and more about confirming which of those two vintage sizes is actually on the vehicle.

Checking the current tire size and wheel setup is important before ordering, especially on a collector vehicle that may have seen wheel changes over time. Once the existing size is confirmed, the next decision is whether to stay with a traditional bias-ply tire in that size or compare the available radial-equivalent options for road use.

The 1965 Amphicar uses a 13-inch rim diameter with both of its primary tire sizes, 640-13 and 650-13. That shared rim diameter simplifies the basic wheel question, since both fitments are built around the same 13-inch wheel size rather than different diameters across sub-models.

Rim diameter is only the first check. Wheel width still matters, especially if the vehicle has replacement wheels or an older set of rims with uncertain specifications. Looking at the actual wheel, the current tire size, and the intended tire's rim-width range helps avoid choosing a tire that matches the diameter but is not well suited to the wheel itself.

On a 1965 Amphicar, 640-13 is a vintage numeric bias-ply size. The 640 portion refers to an approximate nominal section width of 6.40 inches, and the 13 identifies the rim diameter in inches. It is an older sizing format that modern buyers usually encounter only on vintage, specialty, and restoration-oriented vehicles.

Understanding that format helps when comparing period-style bias-ply tires with modern radial equivalents. The size code tells you the tire was built for a 13-inch rim, but it does not remove the need to verify wheel width and general clearance. That becomes especially important if the Amphicar has replacement wheels or has been stored for a long period before returning to the road.

For the 1965 Amphicar, 640-13 is a bias-ply primary tire size. It uses the older numeric sizing system associated with vintage bias-ply construction, and the available 640-13 product is built in a classic bias-ply tire series with a wide whitewall sidewall treatment.

That matters because keeping the original construction style preserves the vehicle's traditional tire presentation and period feel. An owner considering a radial alternative should treat that as a separate fitment decision rather than assuming the original size automatically converts. Wheel width, overall dimensions, and body or steering clearance all deserve a fresh check before making the change.

Radial equivalents for 640-13 include 175R13 as an 80-series metric radial, P175/75R13 as a 75-series P-metric radial, P185/70R13 as a 70-series P-metric radial, and 650R13 as a bias-look radial equivalent. Those options give the 1965 Amphicar several paths for moving from a vintage numeric bias-ply size into a radial format.

Each equivalent uses a different sizing convention, so the choice is not just about construction but also about how the tire is described and presented. The recommended rim-width range is 4 to 6 inches, which gives a useful starting point, but the actual wheel, vehicle clearance, and current setup still need to be confirmed before selecting one of those radial alternatives.

A bias-look radial equivalent is available for the 1965 Amphicar in size 650R13. That size can be considered as a radial alternative to the original 640-13 and 650-13 bias-ply fitments while aiming for a more traditional visual character than a modern-looking metric radial usually provides.

That makes it especially interesting for owners who want a vintage-style appearance without staying strictly with bias-ply construction. Even so, a bias-look radial is still a radial tire, not a bias-ply tire, and it should be checked like any other conversion. Wheel width, overall dimensions, and clearance at the fenders and steering should all be verified before use.

Choosing a 650-13 tire for a 1965 Amphicar starts with confirming that 650-13 is the size already on the vehicle and that the wheel is a 13-inch fitment suited to that tire. From there, the meaningful differences are construction style, tire series, sidewall appearance, and wheel-width compatibility.

In 650-13, the available products include Coker Classic and US Royal offerings with both wide whitewall and narrow whitewall styles. That gives the buyer room to match the tire to a more traditional or slightly subtler presentation. The right choice depends on the vehicle's current wheel setup, intended appearance, and whether the goal is restoration-oriented display or regular road use.

The available sidewall styles for 1965 Amphicar tires include wide whitewall and narrow whitewall treatments. The 640-13 product uses a wide whitewall, while 650-13 choices are available in both wide whitewall and narrow whitewall versions, giving more visual flexibility within that larger size.

Sidewall style is one of the biggest appearance decisions on a vehicle like an Amphicar because the tire has a strong effect on the car's stance and period character. It is worth deciding first whether the goal is a more prominent vintage whitewall look or a cleaner, lower-key whitewall presentation, then matching that preference to the confirmed tire size.

Tires for the 1965 Amphicar are available from BFGoodrich, Coker Classic, and US Royal. BFGoodrich appears in 640-13 through the Silvertown Classic Bias Ply line, while 650-13 options are available from Coker Classic and US Royal in their respective classic bias-ply series.

Brand is only one part of the selection process on this vehicle. The more important comparisons usually come down to using the correct size, matching the tire to the wheel, and choosing the sidewall style that suits the vehicle's appearance. Once those points are settled, the available brand and series options become easier to compare in a meaningful way.

A period-style 1965 Amphicar usually starts with one of its original bias-ply fitment sizes, 640-13 or 650-13, on a 13-inch rim. Staying with a bias-ply tire preserves the vintage sizing format and visual character that suit a mid-1960s collector vehicle, especially when paired with an appropriate whitewall style.

The exact choice depends on which size is already on the vehicle and how closely the owner wants to follow a traditional presentation. Wide whitewall and narrow whitewall options create different visual effects, but neither should be assumed to be exact factory-original without vehicle-specific historical verification. For restoration work, appearance, wheel compatibility, and confirmed fitment should all be considered together.

Tire construction changes the visual character of a restored 1965 Amphicar more than many owners expect. A bias-ply tire keeps the vintage format and traditional look associated with the vehicle's original era, while a radial equivalent can introduce a more modern presentation even when the overall sizing is selected carefully.

That does not automatically make one choice right and the other wrong. A restoration-focused owner may prefer bias-ply construction for period style, while a driver may consider a radial or bias-look radial for road use. The important point is to decide whether the priority is historical appearance, driving preference, or a balance of both before selecting the final tire.

Modifications can affect tire fitment on a 1965 Amphicar, even when the vehicle still uses one of its correct 13-inch tire sizes. Aftermarket wheels, altered wheel width, suspension changes, or body modifications can all change how a 640-13, 650-13, or radial-equivalent tire sits within the wheel opening.

A collector vehicle should never be judged by the catalog size alone if it has been changed over the years. Measuring the wheel, checking steering travel, and looking for clearance at the fenders and suspension are all worthwhile before mounting new tires. That extra verification becomes especially important when moving from a bias-ply tire to any radial alternative.

Before driving a 1965 Amphicar on new tires, inspect the wheels for correct diameter and condition, confirm that the mounted tire size matches the vehicle setup, and check that each tire is inflated appropriately for its application. It also makes sense to look for any obvious rubbing points at the fenders, suspension, and steering components.

A short test drive should be followed by another visual inspection to make sure the tires are seating and clearing properly. On a low-use collector vehicle, it is also smart to examine brake condition, wheel hardware, and general chassis soundness before regular road use. New tires help only when the rest of the supporting components are ready as well.

Tires on a collector 1965 Amphicar should be checked regularly for air loss, cracking, bulges, cuts, and uneven tread wear, whether the vehicle uses 640-13 or 650-13. Low annual mileage does not prevent aging, so condition matters just as much as tread depth on a specialty vehicle that may spend long periods parked.

Proper storage also helps preserve the tires. Keeping the Amphicar away from prolonged sunlight, excess heat, moisture, and ozone sources can reduce premature deterioration. Pressure checks should be part of routine maintenance before any drive, and any tire that shows visible damage or age-related deterioration deserves closer evaluation before the vehicle returns to the road.