1959 Alvis TD 21 Tires

The 1959 Alvis TD 21 uses two primary tire sizes: 640-15 and 670-15. Both are bias-ply sizes built for 15-inch wheels, and the TD 21 Base is associated with either size rather than one exclusive fitment across every car still on the road today.

That means the best starting point is the car itself. Check the size on the current tires, confirm the wheel diameter, and compare wheel width before replacing anything. On a collector car that may have changed wheels or tires over time, the correct choice is the size that matches the actual setup and leaves proper room at the fenders and steering components.

The 1959 Alvis TD 21 uses a 15-inch rim with either of its primary tire sizes, 640-15 or 670-15. The final number in both vintage numeric bias-ply sizes identifies the wheel diameter, so either fitment is built around a 15-inch wheel rather than a modern metric rim standard.

Wheel diameter is only part of the fitment picture, especially on an older touring car. Rim width should also be checked before selecting a replacement tire or moving to a radial equivalent. A TD 21 that has been fitted with aftermarket wheels, restored with different rims, or changed over the years may need a closer wheel inspection before the next set goes on.

A 640-15 is a vintage numeric bias-ply tire size. The 640 designation refers to a nominal section width of about 6.40 inches, while the 15 identifies a 15-inch wheel diameter. It is an older sizing system that predates modern P-metric and euro-metric radial tire markings.

Understanding that format helps when comparing period-style bias-ply tires with radial alternatives. A modern equivalent may use a completely different size code even though it is meant to serve as the radial counterpart. For a TD 21, the important step is not translating the number in isolation, but matching the tire to the car's actual wheel width, overall setup, and intended use.

For the 1959 Alvis TD 21, 640-15 is a primary bias-ply tire size. The available products in that size are vintage-style bias-ply offerings, which makes it the traditional construction choice for an owner who wants to stay with the original-era sizing format and overall presentation.

A radial alternative can still be considered, but it should be treated as an equivalent rather than the same tire. Wheel width, clearance, and the car's intended driving pattern all matter before making that move. Bias-ply and radial construction can also change the car's look and road feel, so the choice should match both the setup and the owner's goals.

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. Each one is an alternative tied to the original 670-15 sizing rather than the same tire in a different label.

Those options give a TD 21 owner several ways to approach the conversion, from a more conventional metric radial format to a bias-look radial that keeps a more traditional visual character. The recommended rim-width range for these 670-15 equivalents is 5 to 7 inches, and final selection should still account for wheel dimensions, vehicle clearance, and the car's present configuration.

Start by confirming the TD 21's actual tire size, wheel diameter, and wheel width, then compare those measurements with the radial equivalent you are considering. The 640-15 and 670-15 fitments each have different radial alternatives, so the first step is matching the radial size to the bias-ply size already in use on the car.

A careful conversion also includes checking clearance at the fenders and steering components, plus the condition of the suspension and alignment. On an older grand touring car, decades of wheel changes or ride-height changes can affect results. The goal is not simply switching construction, but choosing a radial equivalent that works with the TD 21's actual wheels and road-use expectations.

Begin with the correct primary size on the car, since a 1959 Alvis TD 21 may use either 640-15 or 670-15. From there, compare construction, wheel compatibility, sidewall style, brand, tire series, and any load information that matters to the way the car will be driven and presented.

A restoration-oriented owner may focus on a traditional bias-ply look, while a regular road-use owner may also evaluate the available radial equivalents. It helps to decide whether the priority is appearance, touring comfort, or preserving the car's vintage visual balance. Once the size is confirmed, the better choice is the tire that suits the car's actual wheels and the owner's intended use.

The available sidewall styles for 1959 Alvis TD 21 tires include blackwall, narrow whitewall, and wide whitewall, depending on the size and series selected. Both 640-15 and 670-15 offer more than one visual approach, with 670-15 especially broad in its whitewall and blackwall selection.

That makes sidewall choice an important part of the tire decision, not just a cosmetic afterthought. A blackwall gives a restrained and purposeful look, while narrow or wide whitewalls create a more formal period-style presentation. The right choice depends on how the TD 21 is restored, how authentic-looking the owner wants the stance to feel, and which size is actually mounted on the car.

Tires for the 1959 Alvis TD 21 are available from BFGoodrich, Firestone, Avon, Excelsior, US Royal, Universal Vintage Tire, Goodyear, Coker Classic, and STA. Brand availability varies by size, with 640-15 carrying a smaller assortment and 670-15 opening up a much broader selection of period-style bias-ply products.

Brand names are most useful when they help narrow style and series choices within the correct size. Once the car's actual tire size is confirmed, compare the available sidewall treatments, rim-width requirements, and overall look rather than choosing by brand alone. On a collector car like the TD 21, appearance and proper fitment usually matter as much as the name on the sidewall.

A period-style 1959 Alvis TD 21 is usually best approached by starting with the car's primary bias-ply sizes, 640-15 or 670-15, rather than jumping immediately to a modern radial. Both sizes preserve the vintage numeric sizing language that belongs visually to a late-1950s British grand touring car.

From there, the choice comes down to the car's actual wheel setup and the appearance the owner wants to achieve. Blackwall, narrow whitewall, and wide whitewall options are all available, but period-style does not automatically mean one sidewall treatment is exact for every TD 21. When originality matters at a higher level, marque-specific historical references are still worth consulting.

Tire construction has a visible effect on a restored 1959 Alvis TD 21 because bias-ply tires and radial tires do not present the sidewall and overall stance in quite the same way. Staying with a bias-ply fitment keeps the car within its original-era construction style, while a radial equivalent introduces a more modern tire format.

That difference matters even before the car moves. Owners who want a strongly vintage presentation often stay with bias-ply, while others look at radial equivalents for road use and accept a slightly different visual character. If the goal is to split the difference, the 670-15 fitment also has a bias-look radial equivalent that can be considered after wheel and clearance checks.

Yes, modifications can affect tire fitment on a 1959 Alvis TD 21. Changes such as aftermarket wheels, altered wheel width, suspension work, ride-height changes, or body repairs can all influence whether a 640-15, 670-15, or any radial equivalent works properly on the car.

A TD 21 that has been restored over many years may not match its earlier wheel setup exactly, even if it still wears a vintage-looking tire. That is why checking wheel diameter, wheel width, and visible clearance is worthwhile before ordering replacements. The farther the car has moved from its earlier configuration, the more important a hands-on fitment review becomes.

Before driving a 1959 Alvis TD 21 on new tires, inspect basic mechanical and tire-related items together rather than looking at the tires alone. Confirm proper inflation, check that the tires seat correctly on the wheels, and look over the valve stems, wheel hardware, steering response, and visible clearance at full lock if access allows.

A cautious short drive is a smart next step on any collector vehicle. Pay attention to tracking, vibration, rubbing, and any sign that the tire is too close to suspension or bodywork. It also helps to recheck air pressure after the first outing. On an older touring car, small setup issues tend to show themselves early once the car is back on the road.

Collector-car tires on a 1959 Alvis TD 21 should be maintained with regular pressure checks, visual inspections, and sensible storage habits. Whether the car runs 640-15 or 670-15 tires, watch for sidewall cracking, tread damage, bulges, cuts, uneven wear, and slow air loss, especially if the car spends long periods parked.

Storage conditions matter almost as much as mileage on a low-use vintage car. Keeping the TD 21 away from prolonged sunlight, excessive heat, moisture, and ozone sources helps preserve tire condition over time. It is also wise to inspect the tires before any longer drive, because a collector vehicle can age its tires quietly even when the tread still looks serviceable.