1955 Humber Tire Fitment Guide

1955 Humber vehicles use three tire sizes across two model lines: 175R15 and 640-15 for the 1955 Humber Hawk, and 700-15 for the 1955 Humber Super Snipe. All three mount on 15-inch rims, but they are not interchangeable across the full Humber range just because the wheel diameter matches. The 640-15 products list rim-width ranges from 4.00 to 5.00 inches depending on the tire, while 700-15 products list 5.00 to 5.50 inches.

That means the first fitment question is model identification, not simply year and make. Hawk owners also need to decide whether they want the radial 175R15 route or the bias-ply 640-15 route, while Super Snipe owners should focus on finding the correct 700-15 product and matching it to the actual wheel width on the car.

A 640-15 tire on a 1955 Humber uses an older numeric bias-ply size convention. The 6.40 designation is the nominal section-width class, and the 15 is the rim diameter in inches. On the 1955 Humber range, 640-15 applies to the Hawk and is offered as a bias-ply fitment with period-style sidewall choices including wide whitewall and narrow whitewall versions.

That older numeric code matters because it reflects both the era and the construction style. If your Hawk is being restored with authenticity in mind, 640-15 keeps you in the traditional mid-1950s sizing language and appearance. Before selecting one, compare the tire's stated rim-width range to the wheel on the car, since 640-15 products are not all built around the exact same approved wheel width.

A 175R15 tire on a 1955 Humber is a radial size using an older Euro-metric style code. The 175 indicates nominal section width in millimeters, the R identifies radial construction, and the 15 is the rim diameter in inches. Within the 1955 Humber lineup, 175R15 is used on the Hawk rather than the Super Snipe.

For a Hawk owner, that code signals a different construction philosophy from the 640-15 bias-ply option, even though both fit 15-inch wheels. Radial and bias-ply tires can change steering feel, tracking, and overall character, so it helps to decide whether your goal is a more original-type driving experience or a more modern-feeling road car before choosing between those two Hawk fitments.

For a 1955 Humber Hawk, the choice between 175R15 and 640-15 is mainly a choice between radial and bias-ply construction rather than a simple year-make fitment decision. The 175R15 gives the Hawk a radial option on a 15-inch rim, while the 640-15 keeps it in an older numeric bias-ply format also built for a 15-inch rim. The Super Snipe does not use either choice in the same way, since it centers on 700-15 bias-ply fitment.

Owners restoring a Hawk to a more period-correct presentation usually gravitate toward the 640-15 route, especially when sidewall appearance is part of the goal. Owners who expect more regular road use often prefer to evaluate the 175R15 option. Either way, it helps to settle the construction question before comparing individual products, since that choice shapes the character of the car as much as the size code itself.

1955 Humber tires are available with several sidewall looks, depending on size. In 640-15 for the Humber Hawk, the available styles include wide whitewall and narrow whitewall. In 700-15 for the Humber Super Snipe, the available styles include wide whitewall and blackwall. Those options reflect the kinds of visual choices collectors often make when balancing showroom-era appearance against a plainer touring or service look.

Sidewall style affects the finished stance of the car almost as much as wheel trim. A wide whitewall usually suits a formal mid-1950s presentation, while blackwall reads more understated and practical. Because style offerings change by size, the model and size need to be settled first; once that is done, you can narrow the decision to the look that best fits your restoration goal.

Three brands appear in the available 1955 Humber tire range: BFGoodrich, Firestone, and STA. The 640-15 Hawk fitment is offered by BFGoodrich and Firestone, while the 700-15 Super Snipe fitment is offered by Firestone, BFGoodrich, and STA. The 175R15 Hawk radial fitment is part of the vehicle fitment range, though the current brand mix for that size is not represented in the available product group here.

That brand spread gives buyers more than one path, especially in the bias-ply sizes where sidewall appearance and product character vary. A sensible approach is to choose size and construction first, then compare brands within that lane. For many collector-car owners, the final decision comes down to the visual style they want and whether the tire's approved wheel-width range matches the wheels already on the car.

Rim-width guidance for 1955 Humber tires depends on the size. For 640-15, listed products cover approved rim widths from 4.00 to 5.00 inches, with some specific tires calling for 4.00 to 4.50 inches and others 4.50 to 5.00 inches. For 700-15, the listed products use a 5.00 to 5.50 inch rim-width range. All of these sizes mount on 15-inch wheels, but the wheel width still matters.

That is why a 15-inch wheel alone is not enough to confirm a match. Before fitting a tire, measure the wheel or verify the actual wheel specification already on the car, then compare it to the range for the exact product you are considering. That step is especially important if the car has replacement wheels or if original wheels may have been swapped between models over the years.

Original 1955 Humber wheels can only be treated as broadly compatible at the rim-diameter level, because all listed sizes use 15-inch rims. That common diameter means the Hawk's 175R15 and 640-15, and the Super Snipe's 700-15, all belong to the same basic wheel-diameter family. Rim width is the deciding detail, and the approved ranges differ between 640-15 and 700-15 products.

A Hawk wheel and a Super Snipe wheel should not be assumed identical simply because both accept 15-inch tires. If you are moving between sizes or sorting out a car with mixed parts, verify the actual wheel width before committing to a tire. That is the step that keeps a diameter match from turning into a poor overall fit.

A stored 1955 Humber should be kept away from direct sunlight, electric motors, battery chargers, heaters, and other ozone-producing sources that can accelerate sidewall aging. Clean, dry floors and stable temperatures help, and the car should be rolled periodically or placed on stands if it will sit for long periods. Bias-ply tires, which are used in the 640-15 and 700-15 Humber fitments, are especially prone to flat-spotting during storage compared with radial construction.

That storage routine matters because collector cars often age their tires by time and environment more than by mileage. Hawk owners running 175R15 radials may notice less temporary flat-spotting after storage, while owners on bias-ply sizes should expect the car to need a little running time to smooth out after sitting. Proper storage protects appearance as well as road behavior.

Tires on a 1955 Humber should be judged mainly by age and condition rather than tread depth alone. A good rule for collector vehicles is to begin evaluating them closely once they are around five to seven years old and to treat roughly ten years as a strong replacement point, even if the mileage is low. The DOT date code on the tire sidewall is the reference for age.

That approach fits the way most Humbers are used today, since many survive as occasional-use classics rather than daily drivers. Long periods of storage, underinflation, and heat exposure can age a tire faster than a few weekend trips. If the tires look cosmetically fine but are old, age should carry more weight in the decision than remaining tread.

Tires on a 1955 Humber should be inspected before every drive and again before any longer outing or tour. Look for sidewall cracking, cuts, bulges, uneven wear, embedded debris, and pressure loss. Pay attention to whether the car has begun to pull, shimmy, or develop a vibration that was not there previously, since older collector-car tires can give subtle warnings before a larger failure.

Routine inspection is particularly important on a low-use car because problems often develop while the vehicle is parked rather than while it is being driven. If the car uses older-style hardware or has not been serviced recently, include the spare, valve stems, and wheel condition in the same pre-drive check. A few minutes in the garage is much easier than discovering an issue on the road.

A 1955 Humber Hawk would have belonged to an era when bias-ply tires were still the standard fitment for most production cars, even as radial technology was becoming more visible in parts of Europe. Within the available 1955 Humber fitments, the Hawk uses either 640-15 bias-ply or 175R15 radial, with the bias-ply size aligning most naturally with a period-correct mid-1950s presentation.

For restoration work, that means the first authenticity question is usually construction type, followed by sidewall style. If you are aiming for show-level correctness, verify market-specific expectations with Humber or Rootes marque specialists, since export-market details and owner-installed replacements can complicate what a particular car wore when new. The closer the event standard, the more those details matter.

Correct tire fitment does matter when showing a 1955 Humber, especially at events that judge authenticity closely. Size, construction type, and sidewall style all influence whether the car presents as era-appropriate. A Hawk shown with a modern-looking radial when the judging standard favors original-type bias-ply construction may draw attention, and an obviously mismatched sidewall treatment can do the same even when the tire technically fits the wheel.

The practical takeaway is to match the tire to the level of restoration you are pursuing. For casual local shows, a tasteful tire choice may be enough, but formal judging often rewards a closer reading of period details. Event rules and marque-club guidance are the best references when you want to know how strict the standard will be for your particular Humber.

A 1955 Humber Super Snipe comes from the same period logic as the Hawk, but its available fitment centers on the larger 700-15 bias-ply size. That aligns well with the car's place as Humber's more substantial, more formal saloon in the mid-1950s, when bias-ply construction remained the normal original-equipment pattern for cars of this type. Wide whitewall and blackwall versions are both available today within that size family.

For restoration planning, the construction answer is straightforward because the Super Snipe fitment stays in the bias-ply lane. The next question becomes presentation: blackwall for a plainer look or whitewall for a more upscale period impression. If your car is being prepared for a judged event, use Humber-specific club knowledge to confirm what sidewall treatment best matches your market and restoration objective.

1955 Humber tires can be suitable for highway use when they are the correct size, in sound condition, properly inflated, and matched to the wheel they are intended for. The listed 640-15 and 700-15 products here are bias-ply tires, while the Hawk also has a 175R15 radial fitment. Highway safety in a 1955 Humber is not just about the tire itself; braking, suspension condition, steering condition, and the car's overall mechanical state are just as important on a vehicle of this era.

For real-world driving, treat the whole car as a system rather than assuming a new tire alone makes a vintage car modern. Bias-ply and radial constructions can both be used responsibly, but they deliver different road feel and response. A well-sorted Humber driven within the limits of its tires and chassis is the right goal, especially on longer or faster roads.

Several 1955 Humber tire products list maximum load and pressure figures rather than a one-size-fits-all operating pressure. In 640-15, listed products include 1190 pounds at 32 psi and 970 pounds at 32 psi depending on the tire. In 700-15, listed load-rated products show 1700 pounds at 32 psi. Those figures are tire ratings, not automatic instructions to run every Humber at 32 psi in all conditions.

The best practice is to start with the factory pressure guidance for the specific Humber model and then confirm that the selected reproduction or replacement tire is being used within its rated limits. Do not transfer a pressure assumption from 640-15 to 700-15, or from one product line to another. Pressure choice should follow the model, the tire size, and the exact tire's own specification.

Before a longer drive in a 1955 Humber, inspect each tire for cracking, cuts, bulges, exposed cords, irregular wear, and proper cold inflation. Check that the spare is usable, the wheel hardware is secure, and the valve stems are in good condition. Since Humbers of this age are often driven intermittently, also make sure the tires are not carrying old flat spots or signs of age-related separation from extended storage.

That tire inspection should be part of a broader pre-tour check that includes brakes, cooling, steering, and suspension. A Humber that feels composed around town can still reveal weaknesses once heat and distance build up on the road. Giving the tires a serious look before departure is one of the simplest ways to avoid cutting a good drive short.