1956 Humber Tire Fitment Guide

Three sizes fit 1956 Humber vehicles in this range: 175R15 and 640-15 for the 1956 Humber Hawk, and 700-15 for the 1956 Humber Super Snipe. All three sizes mount on 15-inch rims. Where product fitment details are available, 640-15 tires are built for rim widths from 4.00 to 5.00 inches depending on the product, while 700-15 tires are built for 5.00 to 5.50 inch rims.

That means year and make alone are not enough to choose a tire for a 1956 Humber. A Hawk owner also has a construction decision between radial and bias-ply approaches, while a Super Snipe owner needs the larger 700-15 size. Checking the actual wheel before ordering is especially important on restored cars, cars that have changed hands many times, or any Humber that may have received replacement wheels during its life.

On a 1956 Humber, 640-15 is a traditional numeric bias-ply size. The 6.40 refers to the tire’s nominal section width in inches, and the 15 refers to the wheel diameter in inches. In the 1956 Humber range here, that size belongs to the Hawk and appears in period-style bias-ply construction with whitewall choices ranging from narrow to wide depending on the product.

That code matters because it points you toward a distinctly 1950s fitment style rather than a later radial convention. If your Hawk is being restored with strong attention to factory-era appearance, 640-15 is the size family most buyers look at first. It is still wise to compare the tire’s approved rim-width range with your wheel, because some 640-15 products are intended for slightly narrower rims than others.

On a 1956 Humber, 175R15 is a radial size with a 175-millimeter nominal section width and a 15-inch wheel diameter. The use of the R indicates radial construction. Within the 1956 Humber lineup covered here, 175R15 applies to the Hawk rather than the Super Snipe, so it should be treated as a model-specific fitment choice.

That makes 175R15 a very different kind of selection from 640-15 even though both are associated with the Hawk. One follows later radial sizing practice, while the other follows traditional mid-century numeric bias-ply sizing. A Hawk owner considering 175R15 should confirm wheel condition, wheel dimensions, and the exact product details before moving from a bias-ply setup to a radial one on a restored British saloon.

For a 1956 Humber Hawk, the choice between 175R15 and 640-15 is mainly a choice between radial and bias-ply construction, not simply one of tire diameter. The 640-15 option keeps the car in a traditional numeric bias-ply format closely associated with 1950s presentation, while 175R15 represents a radial approach on the same 15-inch wheel diameter. The Super Snipe does not use either of those interchangeably, because it takes 700-15.

A Hawk restored for period appearance usually leans toward 640-15, especially when whitewall styling matters. A Hawk intended for regular touring may lead an owner to investigate 175R15, provided the wheel and the chosen product are suitable for that setup. The right answer depends on how original you want the car to feel and look, along with whether your priority is strict restoration character or a later-style driving experience.

1956 Humber tires are available with several sidewall treatments depending on size. The 640-15 Hawk fitment appears in wide whitewall and narrow whitewall form, while 700-15 Super Snipe tires are offered in wide whitewall and blackwall versions. Those options let owners tune the visual character of the car without changing the basic size required for the model.

For a mid-1950s Humber, whitewall tires usually create the most period-minded look, especially on a car restored with bright trim and a formal saloon presentation. Blackwalls can suit a plainer appearance or a more understated touring look, and some buyers prefer them for utility-focused applications. The best choice comes down to how your particular car is being presented, since judged originality standards can vary between markets and events.

Brands available for 1956 Humber fitments include BFGoodrich and Firestone in 640-15, with Firestone, BFGoodrich, and STA also appearing in 700-15. The Hawk’s bias-ply 640-15 choices come from BFGoodrich and Firestone, while the Super Snipe’s 700-15 range adds an STA option alongside Firestone and BFGoodrich. Each brand is represented in bias-ply construction within the sizes listed here.

Brand choice on a 1956 Humber often comes down to visual preference, sidewall style, and how closely you want the tire to match a certain period flavor. Firestone and BFGoodrich both offer traditional collector-oriented presentations, while STA’s presence in 700-15 broadens the options for buyers considering a more utilitarian blackwall pattern. Once the correct size is identified, comparing sidewall style and load figure is usually more useful than chasing brand name alone.

Rim-width guidance for 1956 Humber tires depends on size and sometimes on the individual product. In 640-15, approved rim widths run from 4.00 to 4.50 inches on one BFGoodrich version and from 4.50 to 5.00 inches on Firestone versions. In 700-15, the passenger-car tires listed are built for 5.00 to 5.50 inch rims. All of these fitments use a 15-inch rim diameter.

That spread matters because a 1956 Humber can wear the correct nominal tire size yet still have a wheel that falls outside a given product’s preferred width range. The best approach is to confirm the actual wheel width on the car, then match it to the tire you want rather than assuming every tire in the same size is interchangeable. That is especially important on restored British cars where replacement wheels may not match original specifications.

All of the listed 1956 Humber sizes use a 15-inch rim diameter, so they share that basic wheel diameter. Even so, they are not universal across the Humber range because the Hawk uses 175R15 or 640-15 while the Super Snipe uses 700-15, and the approved rim-width ranges differ between the bias-ply sizes that have published wheel-width guidance. Same diameter does not automatically mean same wheel suitability.

A Hawk owner comparing 175R15 and 640-15 still needs to confirm that the specific wheel on the car is appropriate for the exact tire being considered. A Super Snipe owner should not assume its larger 700-15 size belongs on Hawk wheels simply because the rim diameter is also 15 inches. Original wheels can often be retained, but the smart step is matching width and condition to the intended tire rather than relying on diameter alone.

A stored 1956 Humber should be kept in a cool, dry, dark environment away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment that can age rubber prematurely. If the car is on bias-ply tires such as 640-15 or 700-15, long periods of standing can encourage flat-spotting more readily than with a radial. Clean, dry floors and stable inflation pressure also help preserve the tire casing during storage.

Moving the car periodically, rolling it a short distance, or supporting it appropriately during longer layups can reduce stress on one contact patch. Owners who alternate between show use and occasional road use should also keep the spare in the same protected environment, since an old spare is still part of the tire system on a touring car. Storage habits matter as much as mileage on collector vehicles that spend much of the year parked.

Tires on a 1956 Humber usually age out before they wear out, because most collector cars cover limited annual mileage. A sensible rule is to begin evaluating them closely once they are around five to seven years old and to treat about ten years as a serious replacement point regardless of remaining tread. The DOT date code on the tire helps establish age, and visible cracking, hardening, or persistent vibration can shorten that timeline.

That age-based approach is more useful than waiting for tread wear bars on a classic Humber. Bias-ply tires on lower-use cars may still look serviceable while rubber compounds have already hardened beyond what you want for regular road use. If the car’s maintenance history is unclear, establishing the age of every tire, including the spare, is one of the first checks worth making before putting a newly acquired Humber into regular driving rotation.

Tires on a 1956 Humber should be inspected before every drive and again before any longer outing. Look for sidewall cracking, cuts, bulges, uneven wear, tread separation, and any sign that the tire is losing pressure between uses. On cars running tube-type-era bias-ply fitments, valve stems and the overall air-retention pattern deserve extra attention because a car that sits for long intervals may reveal leaks only when checked consistently.

A quick visual check in the garage is good practice, but collector cars benefit from a more deliberate inspection every few months, even during the off-season. Running your hand around the sidewall and tread can reveal problems that are easy to miss at a glance. The older the Humber and the less frequently it is driven, the more valuable that routine becomes, since aging issues often show up long before mileage-related wear does.

A 1956 Humber Hawk would have been associated with period bias-ply fitment when new, and within the sizes used here that traditional route is 640-15. The alternative 175R15 is a radial-size approach for the Hawk, but radial construction was not the default original fitment pattern for mid-1950s British saloons in general. No specific original-equipment brand should be assumed without factory literature or marque-club confirmation.

For restoration purposes, that means 640-15 is the starting point if your goal is to preserve the Hawk’s period-correct stance and visual character. The exact whitewall treatment can matter as much as the size itself when a car is being judged or presented seriously. If your Hawk has a particular export-market history or an unusual delivery specification, a Humber marque specialist or original sales material is the best way to confirm how that individual car was equipped.

Correct tire fitment matters on a 1956 Humber because judges and knowledgeable enthusiasts often notice size, construction type, and sidewall treatment right away. A Hawk shown with a modern radial approach can read differently from one shown on a period-style 640-15 bias-ply, and a Super Snipe’s visual balance is tied to its proper 700-15 size family. Whitewall width and blackwall-versus-whitewall presentation can also affect how authentic the car appears.

That does not mean every event uses the same standard. Some tours and local shows accept practical updates easily, while formal originality judging may be stricter about construction type and sidewall appearance. If the car is being prepared for serious competition, compare your intended tire against event rules and club guidance before mounting a set. A tire can be mechanically serviceable and still look out of step with the restoration level of the car.

For the 1956 Humber Super Snipe, Firestone and BFGoodrich both offer 700-15 bias-ply tires with wide whitewall presentations, a 15-inch rim diameter, and published load figures of 1700 pounds at 32 psi on the examples listed here. Their approved rim-width ranges are also aligned at 5.00 to 5.50 inches. The main visible difference in the versions shown is branding and the styling identity of the tire line rather than a major change in basic fitment spec.

That means the decision often comes down to which brand’s sidewall and overall period character best suits the look of your Super Snipe. Buyers restoring a car to a particular visual theme may have a preference for one heritage name over another even when the size and core specifications are close. Once fitment is confirmed, comparing sidewall style, weight, and presentation details usually tells you more than the brand badge alone.

A properly selected, properly maintained 1956 Humber tire can be suitable for normal highway use, but the answer depends on choosing the correct size for the model and keeping the tires in sound condition. The listed 640-15 and 700-15 offerings are bias-ply tires, while the Hawk also has a 175R15 radial-size option. Because speed-rating information is not consistently shown across the available products here, the specific tire’s sidewall marking should be checked before extended fast-road use.

On a 1956 Humber, overall highway confidence also depends heavily on the car itself. Brakes, steering, suspension condition, wheel trueness, and alignment can matter as much as the tire, especially on a mid-century British saloon designed in a different traffic era. The safe approach is to match the tire to the car, keep speeds realistic for the vehicle’s condition, and inspect everything carefully before asking an older Humber to do sustained modern-road mileage.

Published load figures for 1956 Humber tires in the listed bias-ply sizes are tied to 32 psi on several products. In 640-15, examples shown include 1190 pounds at 32 psi and 970 pounds at 32 psi depending on the tire, while 700-15 passenger-car examples are shown at 1700 pounds at 32 psi. Those figures describe the tire’s rated load relationship at that pressure, not necessarily the vehicle manufacturer’s recommended operating pressure for every Humber application.

The best practice is to start with the pressure guidance from the Humber owner’s literature or marque reference for your exact model, then compare that with the tire manufacturer’s published information for the specific reproduction tire you are using. Do not transfer one size’s pressure habits to another just because the rim diameter is the same. Any car that has changed size, construction type, or wheel specification deserves a careful pressure review after installation.

Before a longer drive in a 1956 Humber, inspect each tire for cracking, cuts, bulges, uneven wear, and signs of air loss, then verify cold pressure and the condition of the spare. On bias-ply applications, pay close attention to sidewall condition and valve stems, since age and storage can affect them more than mileage suggests. The wheel itself should also be checked for damage, and any persistent vibration or pull should be addressed before setting out.

A tire check is only one part of preparing an older Humber for distance. Brake feel, steering play, suspension behavior, wheel-bearing condition, and cooling-system health all deserve attention on a car from this era. If the Humber has been sitting, a short local shakedown drive after rechecking pressures is smarter than going straight onto a fast road. Collector cars reward methodical preparation, and tires are one of the easiest early warning points to evaluate.