1955 Humber Hawk Tires

The 1955 Humber Hawk uses two primary 15-inch tire sizes: 640-15 in a bias-ply format and 175R15 in a radial format. The covered MKV sub-model is associated with both, so the fitment question is less about trim differences and more about which construction the car is set up to use.

Choosing between those sizes starts with confirming the wheel and overall setup on the car today. A Humber that remains restoration-oriented may stay with 640-15 bias-ply tires, while a car using radial construction may call for 175R15. The safest path is to confirm wheel width, present tire size, and available clearance before changing construction or profile.

The 1955 Humber Hawk uses a 15-inch rim diameter with both of its primary tire sizes. That applies to the 640-15 bias-ply fitment and the 175R15 radial fitment, so rim diameter remains consistent even though the construction and sizing formats differ.

Rim diameter is only part of the fitment picture on a car of this age. Wheel width still matters, especially when comparing bias-ply tires to radial alternatives or looking at equivalent metric sizes. Checking the wheel stamping or measuring the wheel directly helps prevent mismatches that can affect tire shape, clearance, and overall suitability.

The 1955 Humber Hawk MKV is associated with the same 15-inch tire-size choices covered for this model: 640-15 in bias-ply construction and 175R15 in radial construction. That means the sub-model does not introduce a separate size path that changes the basic fitment discussion.

The practical question is whether the car still has a traditional bias-ply setup or has been fitted for radial use. A MKV wearing 640-15 tires may be aimed at period-style presentation, while one on 175R15 radials may reflect a different road-use preference. Confirm the actual wheels and the current tire arrangement before selecting replacements.

640-15 is a bias-ply tire size for the 1955 Humber Hawk. It is the vintage numeric format associated with traditional construction, and it is offered in several bias-ply product lines with blackwall, narrow whitewall, and wide whitewall sidewall treatments.

That matters because construction affects both appearance and setup decisions. A car staying close to a mid-1950s presentation often remains on 640-15 bias-ply tires, while a change to radial construction moves into an equivalent-size discussion instead of simply choosing another 640-15. Wheel width, handling expectations, and visual goals should all be considered together.

Radial equivalents for 640-15 include 175R15 as the 80-series metric radial option, P175/75R15 as the 75-series P-metric option, and P185/70R15 as the 70-series P-metric option. These are equivalent comparisons for the 1955 Humber Hawk rather than different ways of writing the same original bias-ply size.

The useful distinction is that each option follows a different radial sizing convention and profile family. A recommended rim-width range of 5 to 6 inches applies to the equivalent comparison, but final selection still depends on the actual wheel, overall tire dimensions, and the room available in the fenders and steering arc.

Start by confirming the wheel diameter and width, then compare the radial size you are considering against the car's existing 640-15 fitment. For the 1955 Humber Hawk, the recognized radial alternatives to 640-15 are 175R15, P175/75R15, and P185/70R15, with a recommended equivalent rim-width range of 5 to 6 inches.

A conversion should also account for how the car is actually configured today. Check steering clearance, fender room, suspension condition, and any wheel changes made over the years. A radial equivalent can be a valid alternative, but it still needs to suit the Humber's present wheels and physical space rather than being treated as an automatic swap.

The first consideration is whether 640-15 matches the way the car is meant to be presented and driven, since it is a bias-ply size for the 1955 Humber Hawk. After that, compare sidewall treatment, tire series, rim-width specification, and construction details among the available bias-ply options.

A blackwall tire gives a restrained traditional look, while narrow and wide whitewalls change the car's visual character significantly. Product details also vary by brand and load specification, with examples such as 1190@32 psi and 970@32 psi appearing in this size. Matching the tire to the wheel and intended use is just as important as matching the size code.

For the 1955 Humber Hawk's 640-15 bias-ply fitment, available sidewall styles include blackwall, narrow whitewall, and wide whitewall. Those options create very different visual impressions even when the size and basic construction stay within the same traditional 15-inch fitment family.

Sidewall choice often comes down to how the car is being finished rather than pure fitment alone. A blackwall can suit a more understated presentation, while whitewall treatments add a stronger mid-1950s visual accent. Since sidewall style does not change the need for proper wheel compatibility, compare appearance only after confirming the underlying tire specification works for the car.

Available 640-15 bias-ply tires for the 1955 Humber Hawk come from BFGoodrich, Firestone, Avon, and Excelsior. Those brands appear across several series, including Silvertown Classic Bias Ply, Firestone Classic Bias Ply, Super Safety Crossply, and Excelsior Bias Ply.

Brand choice should be weighed alongside sidewall style, rim-width suitability, and the overall look you want from the car. Some options focus on blackwall presentation, while others add narrow or wide whitewalls. Instead of choosing by name alone, compare the series character and specifications that actually affect how the tire will suit your Humber.

A period-style 1955 Humber Hawk usually starts with the 640-15 bias-ply size, since it preserves the traditional sizing format and construction associated with the car's era. That size is available in blackwall, narrow whitewall, and wide whitewall versions, giving owners room to shape the car's visual character without leaving the bias-ply category.

Appearance goals should guide the final decision, especially on a restoration-minded British saloon. A restrained car may suit blackwalls, while a more formal or show-oriented presentation may lean toward whitewalls. When absolute originality matters, compare the tire choice with marque references, photos, and other vehicle-specific historical sources rather than relying on style alone.

Tire construction changes more than ride feel on a restored 1955 Humber Hawk; it also changes how the car looks at a glance. A 640-15 bias-ply tire delivers the older sizing format and visual character many owners expect on a mid-1950s saloon, while a 175R15 radial introduces a more modern tire presentation.

That difference becomes noticeable in a restoration where wheel opening fill, sidewall styling, and overall stance matter. Owners focused on preserving a traditional look often stay within the bias-ply path, then fine-tune the result with blackwall or whitewall choices. A radial can still be appropriate, but it usually reflects a different balance between appearance and road-use priorities.

Yes, modifications can affect tire fitment on a 1955 Humber Hawk even when the intended tire size is otherwise appropriate. Aftermarket wheels, changes in wheel width, suspension alterations, ride-height changes, or bodywork differences can all influence how a 640-15 or 175R15 tire sits and clears the car.

That is especially important on older cars that may have changed several times over the decades. A Humber with replacement wheels may not behave the same as one on original-type rims, and a radial equivalent can react differently than a bias-ply tire in the same wheel opening. Measure the actual setup before assuming the original fitment path still applies unchanged.

Before road use, inspect the wheels, valve stems, and tire seating, then confirm that the new tires match the intended size and construction for the 1955 Humber Hawk. It is also wise to check for adequate clearance at full steering lock and to look over the suspension and steering components on a car that may have spent long periods parked.

A collector-era car benefits from a broader once-over before regular driving resumes. Verify tire pressure, watch for early air loss, and make sure there are no signs of rubbing once the car is rolling. Even new tires perform best when the surrounding chassis parts are sound and the wheel-and-tire combination suits the car's present condition.

640-15 tires on a collector 1955 Humber Hawk should be maintained with regular pressure checks, routine visual inspections, and careful storage habits. Look for cracking, bulges, cuts, uneven tread wear, or unexplained air loss, especially on a vehicle that spends more time parked than driven.

Collector cars often age their tires through time and environment as much as through mileage. Keeping the Humber away from prolonged sunlight, excessive heat, moisture, and ozone-producing equipment helps preserve tire condition. Periodic inspections before each outing are a good habit, since a tire that looks acceptable in storage may still need attention before road use.