1965 Amphicar Tire Fitment Guide

1965 Amphicar vehicles use two tire sizes: 640-13 and 650-13. Both fit the Amphicar model and both mount on 13-inch rims. The 640-13 fits wheels in the 4.00- to 4.50-inch width range, while the 650-13 fits wheels in the 4.50- to 5.00-inch range. Both sizes are bias-ply, so the difference is not radial versus bias-ply, but the tire's nominal size and the wheel width it is intended to work with.

That makes wheel measurement especially important before you choose. A 1965 Amphicar owner who already knows the car has 13-inch wheels still needs to verify whether the wheel falls into the narrower 640-13 range or the wider 650-13 range. If the car is a restoration, the sidewall style may influence the decision as well, since the 650-13 offers more whitewall choices.

On a 1965 Amphicar, 640-13 is a numeric bias-ply size. The 6.40 figure is the nominal section width in inches, using the older numeric convention, and the 13 is the wheel diameter in inches. There is no modern metric aspect ratio written into the size the way you would see on a contemporary radial. In the current 1965 Amphicar offerings, this size appears as a bias-ply tire with a wide whitewall and an S speed rating.

That older numeric code matters because it identifies a period-correct tire format for a mid-1960s specialty car. If your 1965 Amphicar is set up for 640-13, you should match that size rather than trying to translate it loosely into a modern metric number. The safest approach is to confirm the wheel width and then compare the sidewall and load details of the actual 640-13 products you are considering.

The 1965 Amphicar range is simple in model count but not limited to one tire size. The Amphicar model uses both 640-13 and 650-13, and both are 13-inch bias-ply sizes. That means there is no split between separate body styles or trim lines, but there is still a genuine fitment distinction within the year and make. The deciding factors are wheel width and the size already established on the car.

For a buyer, that means year and make are only the starting point. A 1965 Amphicar owner should inspect the existing tire size, check the wheel width, and decide whether the current setup reflects the intended restoration standard. Since both sizes belong to the same model, it is easy to assume they are interchangeable in every case, but the wheel-width ranges show why that assumption should be checked first.

Both 640-13 and 650-13 are correct-era bias-ply choices for a 1965 Amphicar, so the decision is mainly about matching the car's wheel width and established size rather than choosing between two different construction types. The 640-13 fits a 4.00- to 4.50-inch wheel and appears with a wide whitewall from BFGoodrich. The 650-13 fits a 4.50- to 5.00-inch wheel and is available from Coker Classic and US Royal in both narrow and wide whitewall styles.

If your Amphicar is already restored, the best path is usually to keep the size that matches the wheel and the car's visual character. If you are rebuilding the car and deciding from scratch, look first at wheel width, then at the sidewall appearance you want. The 650-13 gives you more style choices, while the 640-13 stays closer to a single traditional presentation.

1965 Amphicar tires are available with whitewall styling in more than one form. The 640-13 is offered with a wide whitewall, while the 650-13 comes in both wide whitewall and narrow whitewall versions. That means the year and make support a distinctly period presentation, but with some flexibility in how bold the sidewall looks. All of the current options remain bias-ply, which keeps the overall appearance appropriate to the era.

Sidewall style can have an outsized effect on how a small 1960s car presents, and that is especially true on an Amphicar because the body design is so clean and distinctive. A wide whitewall leans into mid-century show and restoration character, while a narrow whitewall gives a slightly more restrained look. If the car will be judged, check your event's expectations before settling on one style.

Three brands cover 1965 Amphicar tire sizes: BFGoodrich, Coker Classic, and US Royal. BFGoodrich appears in 640-13, while Coker Classic and US Royal both offer 650-13 options. Within the 650-13 size, both brands are available in narrow whitewall and wide whitewall forms. That gives Amphicar owners a choice among established vintage-tire names without moving away from the correct numeric bias-ply format.

Brand choice on a collector car often comes down to the combination of size, sidewall look, and the period image you want the car to carry. Since the 640-13 and 650-13 do not have the same brand overlap, it helps to settle the size first and then compare the available whitewall presentation within that size. That approach avoids choosing by brand before confirming fitment.

Rim width depends on the tire size you use on a 1965 Amphicar. The 640-13 fits a 13-inch rim that is 4.00 to 4.50 inches wide, while the 650-13 fits a 13-inch rim that is 4.50 to 5.00 inches wide. Both sizes share the same rim diameter, but they do not share the exact same width range. That overlap at 4.50 inches is useful, but it does not make every wheel equally suitable for both sizes.

Measure the wheel before assuming the tire on the car now is the only correct option. If your Amphicar wheel is at the narrower end, the 640-13 will be the more natural match; if it is wider, the 650-13 becomes the better fit. On a restoration, confirming wheel width early can prevent a mismatch between the look you want and the tire the wheel can properly support.

Inner-tube status is not marked the same way across 1965 Amphicar products, so tube use should be confirmed on the specific tire and wheel combination you plan to run. Both 640-13 and 650-13 are offered as vintage-style bias-ply tires, and the wheel condition matters just as much as the tire itself when deciding tube practice on a collector car. The actual sidewall marking and the wheel's design should guide the final setup.

That is especially important on an Amphicar, where long storage periods and specialized use can make wheel condition easy to overlook. Before final assembly, inspect the wheel carefully, confirm the tire's sidewall marking, and match the valve stem and tube choice to the intended installation. If the car is being restored to show standards, a marque specialist can help confirm what is most appropriate for your exact setup.

Original 1965 Amphicar wheels can potentially work with both tire sizes because both 640-13 and 650-13 use a 13-inch rim diameter. Rim diameter compatibility alone is not the whole answer, though, because the 640-13 calls for a 4.00- to 4.50-inch wheel and the 650-13 calls for a 4.50- to 5.00-inch wheel. A wheel at 4.50 inches sits in the overlap between the two ranges, while wheels outside that overlap do not.

That means many owners should think of wheel width as the deciding factor, not just wheel diameter. If your original wheels measure 4.50 inches wide, either size may be workable from a rim-width standpoint. If they measure narrower or wider than that, one size becomes the clearer fit. Checking the actual wheel before mounting tires is the best way to avoid avoidable fitment issues.

A 1965 Amphicar should be stored in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, furnaces, and other ozone-producing sources that can accelerate sidewall cracking. Because the Amphicar uses bias-ply tires in both 640-13 and 650-13 sizes, long periods of static storage can also encourage flat-spotting. Keeping the car clean and dry before storage matters even more on an amphibious collector car, where moisture exposure may have been part of its past use.

For longer layups, maintain inflation, move the car periodically, or place it on stands if the storage period will be extended and the chassis supports are suitable. It also helps to keep the spare in the same controlled environment rather than leaving it in a damp compartment. Good storage habits preserve both the tire and the driving feel you expect when the Amphicar returns to the road.

Tire life on a 1965 Amphicar should be judged more by age and condition than by mileage. Collector tires often see limited annual use, so a tire can look lightly worn but still be aging internally. A sensible rule is to begin careful evaluation around five to seven years from the date code and to treat the ten-year point as a serious replacement consideration even if tread remains. That approach applies to both 640-13 and 650-13 bias-ply tires.

The practical takeaway is to inspect the DOT date code and the sidewalls, not just the tread depth. Amphicars often spend long periods parked, shown, or moved only occasionally, which can hide age-related deterioration. If there is any question about cracking, hardening, or irregular shape, replacing the tire is usually the wiser move than stretching service life on a rare and specialized vintage car.

Tires on a 1965 Amphicar should be inspected before every drive and again before any longer outing. Look for sidewall cracking, cuts, bulges, uneven wear, and pressure loss, and do not forget the spare. Since both Amphicar sizes are bias-ply, they can telegraph age and storage effects differently than modern radials, especially after the car has been sitting. The inspection should include valve-stem condition and a close look at the wheel itself.

Routine checks matter because a low-use collector car can develop problems between drives rather than during regular mileage accumulation. On a car with unusual use history like an Amphicar, it is also smart to pay attention to corrosion around the wheel and valve area. A two-minute inspection before heading out can reveal issues early and help you avoid spoiling a drive or event with a preventable tire problem.

A 1965 Amphicar Amphicar would have been equipped in the bias-ply era, and the two correct-format sizes for the year are 640-13 and 650-13. Both are numeric bias-ply sizes on 13-inch rims, which fits the period and the vehicle's original design context. Whitewall presentation was a normal visual theme for many mid-1960s passenger cars, and the available Amphicar tires continue that look with both wide and narrow whitewall options depending on size.

If you are restoring a specific car, the next step is to verify what size it was set up to use rather than assuming every Amphicar left the factory the same way. Market differences, replacement history, and prior restoration choices can all affect what is on the car today. For a market- or event-specific originality check, Amphicar clubs and marque specialists remain the best resource.

Correct tire fitment does matter when showing a 1965 Amphicar, especially because the car's novelty and rarity tend to make observers look closely at the details. Judges and knowledgeable enthusiasts often notice whether the tire uses the right period construction, the right overall size family, and a sidewall style that suits the era. On a 1965 Amphicar, that means staying with numeric 13-inch bias-ply sizing rather than moving to an obviously modern metric radial look.

Whitewall treatment can be part of that discussion too, since a narrow or wide whitewall changes the car's presentation even when the tire is otherwise correct. If the car will compete in a strict originality class, use the judging standards for that event and compare them against the car's historical setup. A tire that looks broadly period-correct may still miss the mark for concours-level authenticity.

For a 1965 Amphicar in 650-13, Coker Classic and US Royal share the same basic fitment envelope. Both are bias-ply 13-inch tires, both fit 4.50- to 5.00-inch rims, both carry a maximum load of 1,150 pounds at 32 psi, and both weigh 18 pounds in the versions available here. The practical difference is in brand identity and sidewall presentation, since each brand offers both narrow whitewall and wide whitewall choices in this size.

That means your decision is less about technical fitment and more about visual preference and brand heritage. If you already know you need a 650-13, compare the sidewall width you want first and then the brand that best fits the theme of your restoration. Because the measured fitment details are so closely matched, appearance becomes the more meaningful separator between these options.

1965 Amphicar tires can be suitable for highway driving when they are in good condition, correctly fitted, and used within their design limits. The 640-13 offering carries an S speed rating, which corresponds to a 112 mph ceiling, and the 650-13 products are traditional bias-ply collector tires with load ratings of 1,150 pounds at 32 psi. On a mid-1960s Amphicar, the car's own age, braking, suspension, steering, and overall condition are usually more relevant to real-world highway confidence than an extremely high speed capability.

The practical question is not whether the tire invites modern high-speed driving, but whether the whole vehicle is ready for sustained road use. Keep inflation correct, inspect the tires before departure, and treat the Amphicar like the specialized vintage machine it is. For longer drives, moderate speeds and a thorough pre-trip check are more important than trying to use the tire's rating as a target.

Pressure should be chosen by matching the tire manufacturer guidance with the vehicle's factory recommendation, not by guessing from the size name alone. The 640-13 BFGoodrich tire carries a maximum load of 1,045 pounds at 32 psi, and the 650-13 options carry a maximum load of 1,150 pounds at 32 psi. Those figures tell you the tire's rated load at that pressure, but they are not automatically the same thing as the vehicle's ideal operating pressure in service.

Start with the original owner's manual or factory placard if it is available for your Amphicar, then compare that against the tire maker's limits and recommendations for the specific product you are using. Do not transfer a pressure figure from 650-13 to 640-13 or vice versa just because both are 13-inch tires. Matching pressure to the exact size and application will protect ride quality, wear, and handling balance.

Before a longer drive in a 1965 Amphicar, inspect each tire for cracking, cuts, bulges, unusual wear, and proper inflation, and check that the spare is also serviceable. Confirm that the tire size on the car matches the wheel width, since the 640-13 and 650-13 use different width ranges even though both are 13-inch sizes. Look closely at the valve stems and wheel condition as well, especially on a car that may have seen moisture exposure in past use or storage.

A longer outing in an Amphicar should also include the broader mechanical checks any specialized vintage car deserves: brakes, steering, fluids, electrical system, and basic roadworthiness. Tires are only one part of that preparation, but they are the part that meets the road. Taking a few extra minutes to inspect them thoroughly can make a major difference in confidence and reliability once you are underway.