1964 Amphicar Tire Fitment Guide

1964 Amphicar vehicles use two tire sizes: 640-13 and 650-13. Both sizes apply to the Amphicar model, and both mount on 13-inch wheels. The 640-13 products fit 4.00- to 4.50-inch rims, while 650-13 products fit 4.50- to 5.00-inch rims.

That means year and make alone are not quite enough to choose a tire for a 1964 Amphicar. You should verify the actual size already fitted to the car and confirm wheel width before selecting between the two. Once that is settled, the next choice is mostly visual, since both sizes are bias-ply and aimed at an era-correct presentation.

On a 1964 Amphicar, 640-13 is a numeric bias-ply tire size. The 640 is the nominal section-width designation used in period sizing, and the 13 identifies the wheel diameter in inches. In current Amphicar fitment coverage, 640-13 appears as a bias-ply tire with a wide whitewall sidewall treatment.

Modern buyers sometimes expect a metric size with an aspect ratio, but that is not how many early-1960s small specialty cars were sized. If your 1964 Amphicar calls for 640-13, the important checks are wheel diameter, approved rim width, and whether you want the narrower overall fitment used on some cars of this type. It is best treated as a period-size code rather than translated casually into a modern metric equivalent.

On a 1964 Amphicar, 650-13 is also a numeric bias-ply size. The 650 indicates a nominal section-width class that is slightly wider than 640-13, and the 13 still denotes a 13-inch rim diameter. For Amphicar applications, 650-13 is available with both narrow whitewall and wide whitewall styling.

That broader sidewall-style choice makes 650-13 especially useful when an owner wants to fine-tune the car's look without moving away from an era-appropriate bias-ply construction. The practical step is to confirm your wheel width, because 650-13 wants a slightly wider approved rim range than 640-13. On a specialty car like a 1964 Amphicar, that detail matters just as much as the tire's appearance.

The right choice for a 1964 Amphicar starts with the size your car is set up to use, not with a universal upgrade path. Both are 13-inch bias-ply tires, but 640-13 fits 4.00- to 4.50-inch rims while 650-13 fits 4.50- to 5.00-inch rims. The 650-13 also has more sidewall-style variety, while 640-13 is centered on a single wide-whitewall offering.

If your goal is straightforward replacement, match the existing size and verify the wheel width. If you are restoring the car and deciding between the two, use the wheel itself and any surviving fitment history for your specific Amphicar as the guide. Because both are period-style bias-ply sizes, the difference is more about correct fit and appearance than about moving from vintage to modern construction.

1964 Amphicar tires are available with whitewall styling in more than one form. The 640-13 size is offered as a wide whitewall, while 650-13 is available in both wide whitewall and narrow whitewall versions. That gives Amphicar owners a choice between a fuller early-1960s whitewall look and a more restrained presentation within the same basic bias-ply format.

For a show-oriented restoration, sidewall width can change the car's visual balance almost as much as the wheel and hubcap design. Buyers trying to match a particular period photo or restoration standard should compare the whitewall width already associated with their car before choosing. If the goal is simply a clean era-appropriate appearance, either wide or narrow whitewalls can keep a 1964 Amphicar in character.

Three brands cover 1964 Amphicar fitments in the two original-style sizes: BFGoodrich, Coker Classic, and US Royal. BFGoodrich appears in 640-13, while Coker Classic and US Royal both offer 650-13. All of these options stay within bias-ply construction, which suits the car's period and the kind of restoration work Amphicars usually receive.

Brand choice on a 1964 Amphicar often comes down to which size you need first and which whitewall treatment you want second. If your car uses 650-13, you have the widest brand and style spread. If it uses 640-13, the path is narrower, so it becomes even more important to confirm size and wheel compatibility before committing to a tire.

1964 Amphicar tire rim-width requirements depend on the size. The 640-13 fits rims from 4.00 to 4.50 inches wide, while the 650-13 fits rims from 4.50 to 5.00 inches wide. Both sizes use a 13-inch wheel diameter, but they are not intended for exactly the same wheel width range.

That overlap at 4.50 inches is useful, but it should not be treated as blanket permission to swap sizes without checking the wheel. Measure the wheel or verify it through the car's existing setup before selecting a tire. On a 1964 Amphicar, proper rim width matters for section shape, sidewall profile, and the overall period-correct stance of a very distinctive body.

1964 Amphicar tire products in these sizes do not carry a tube-type or tubeless marker in the size designation. Since both fitments are bias-ply tires used on a specialty early-1960s vehicle, tube decisions should be made by looking at the wheel design, the tire's own sidewall markings, and the manufacturer's instructions for the exact product you choose.

That is especially important on a 1964 Amphicar because wheel condition and sealing matter as much as the tire itself. Before installation, inspect the wheel for corrosion, pitting, or previous repairs, and verify valve-stem and bead-seat condition. If a tube is required for your wheel-and-tire combination, use the correct tube and flap arrangement where appropriate rather than assuming every bias-ply fitment is handled the same way.

Original 1964 Amphicar wheels can use both tire sizes only if the wheel width falls within the approved range for the tire being considered. Both 640-13 and 650-13 mount on 13-inch rims, so wheel diameter is shared, but the width requirement differs. The 640-13 prefers 4.00 to 4.50 inches, while the 650-13 prefers 4.50 to 5.00 inches.

A 4.50-inch wheel sits at the overlap point and is the most flexible scenario. Wheels narrower than that point toward 640-13, and wider wheels point toward 650-13. Because many Amphicars have been restored or reworked over the decades, checking the actual wheel on the car is more useful than assuming every surviving 1964 Amphicar still has the same wheel specification it left with.

A 1964 Amphicar should be stored in a cool, dry space away from direct sunlight, electric motors, battery chargers, and other ozone sources that can age rubber. Keep the tires properly inflated, avoid prolonged contact with standing moisture, and move the car periodically if it will sit for long stretches. Because Amphicar ownership often involves seasonal use, storage habits have an outsized effect on tire condition.

Bias-ply tires are more prone to temporary flat-spotting during long static storage than many later radials, so the first few miles after storage may feel different until they warm and round out. If the car will be parked for an extended period, some owners use stands or increase movement intervals to reduce stress on the casing. The goal is preserving the tire shape and sidewall condition, not simply protecting the tread.

Tire life on a 1964 Amphicar is usually judged more by age and condition than by mileage. Collector-car tires are commonly evaluated closely once they reach about five to seven years of service, and replacement becomes a serious consideration as they approach ten years, even if tread depth still looks healthy. The DOT date code on the tire is the starting point for understanding age.

That age-based approach matters because an Amphicar often covers limited miles but may spend long periods parked, exposed to humidity changes, or taken out only for events. Sidewall cracking, hardening, loss of pressure, and visible casing distortion are more meaningful than odometer use alone. A lightly driven 1964 Amphicar can still need new tires if age has overtaken appearance.

Tires on a 1964 Amphicar should be inspected before every drive and again before any longer outing or tour. Look for sidewall cracking, cuts, bulges, uneven wear, signs of impact damage, and any loss of air pressure since the last use. On a low-volume specialty car, a quick inspection is one of the simplest ways to avoid spoiling a drive with a preventable tire issue.

A more detailed check every few months is wise even when the car is not being driven often. Pay close attention to valve stems, bead areas, and the spare, since emergency tires are often the oldest ones on a collector vehicle. If your final wheel-and-tire combination uses tubes, include stem alignment and any signs of chafing or leakage in the inspection routine.

The 1964 Amphicar Amphicar belongs to an era when bias-ply construction was standard equipment for many small specialty cars, and the fitment choices here remain within that bias-ply pattern. The sizes associated with the model are 640-13 and 650-13, both on 13-inch wheels. Original-equipment brand choice could vary by market and delivery circumstances, so size, construction, and overall appearance matter more than assuming one universal factory brand.

For a highly exact restoration, use the surviving tires, manuals, delivery photos, or a recognized Amphicar club as the final authority on what your specific car wore when new. That is especially helpful for whitewall width and market-specific presentation. In most cases, staying with one of the correct bias-ply 13-inch sizes keeps a 1964 Amphicar much closer to its period character than substituting a modern-format tire.

Correct tire fitment matters on a 1964 Amphicar because judges and knowledgeable enthusiasts often notice tire construction, size, and sidewall style immediately. A bias-ply tire in the proper 13-inch period size aligns with the car's era, while an obviously modern-format replacement can disrupt the visual authenticity of a specialty vehicle that already stands out. Whitewall width can also change the car's show-field appearance considerably.

That does not mean every event uses the same standard, but it does mean tire choice should be intentional. If your Amphicar is being prepared for marque judging, consult the club or event rules for how strictly originality is enforced. Matching the tire's size family and sidewall look to the car's period is often one of the easiest ways to improve presentation without altering the vehicle itself.

For the 1964 Amphicar, both Coker Classic and US Royal offer 650-13 bias-ply tires with the same 13-inch rim diameter, the same 4.50- to 5.00-inch rim-width range, and the same load figure of 1150 pounds at 32 psi. Each brand is available in both narrow whitewall and wide whitewall versions. Their shared fitment profile means the main differences are brand identity and the visual whitewall treatment you choose.

That makes the comparison simpler than it first appears. If your wheel and size requirement point to 650-13, you can focus on the look you want on the car and any brand preference you have for the restoration. Since the hard specifications are closely aligned, many Amphicar owners will make this choice by matching period appearance rather than by chasing a major difference in dimensions or load capacity.

1964 Amphicar tires can be suitable for highway driving when they are in good condition, correctly inflated, and used within their intended speed capability. The 640-13 fitment carries an S speed rating, which corresponds to a ceiling of 112 mph. The 650-13 products here do not show a speed letter in the size description, so the tire's own sidewall marking should be checked before sustained higher-speed use.

In real Amphicar use, the vehicle's age, braking system, suspension condition, and specialty design usually matter more than chasing the upper edge of tire capability. A sound tire is only one part of a safe road car. Before any highway trip, confirm pressure, inspect for age-related cracking, and make sure the rest of the car is ready for the pace you intend to drive.

Inflation pressure for a 1964 Amphicar should begin with the factory recommendation for the car, then be checked against the tire's own rated information. The 640-13 size carries a maximum load of 1045 pounds at 32 psi, and the 650-13 size carries a maximum load of 1150 pounds at 32 psi. Those figures are tire capacity references, not automatic instructions to run every Amphicar at maximum pressure.

For day-to-day use, the best practice is to consult the owner's manual or marque reference for vehicle pressure guidance and then confirm that your chosen tire is being used within its rated limits. Do not transfer a pressure assumption from one size to the other just because both fit 13-inch wheels. Pressure tuning on a light specialty car affects ride, steering feel, and tire wear noticeably.

Before a longer drive in a 1964 Amphicar, inspect the tires for sidewall cracking, tread separation, cuts, bulges, embedded debris, and stable air pressure. Check the spare as carefully as the four road tires, since a seldom-used spare is often the oldest tire on the car. A visual inspection of valve stems and the wheel condition is also worthwhile before heading out.

Tires are only one part of the pre-drive routine on a car of this type. Because the Amphicar is an unusual early-1960s specialty vehicle, a sensible road-trip check also includes brakes, steering, suspension, wheel bearings, and fluid condition. If the car has been sitting, take a short local drive first and pay attention to vibration, pull, or unusual steering response before committing to a longer trip.