1956 Imperial C73 Tires

The 1956 Imperial C73 uses an 820-15 tire size. That is a numeric bias-ply fitment for a 15-inch rim, and the covered V8 Custom sub-model uses the same primary size.

That makes the fitment question fairly simple, but the selection question still matters. An 820-15 can be found in different sidewall treatments and tire series, so the next step is confirming the wheel dimensions on the car and deciding whether the goal is a blackwall look, a whitewall presentation, or a carefully evaluated radial equivalent.

The primary tire fitment for the 1956 Imperial C73 is built around a 15-inch rim. The 820-15 size itself confirms that 15-inch wheel diameter, which is the key rim measurement for this application.

Rim diameter is only part of the picture, especially on an older luxury car that may have changed wheels over time. It also helps to verify actual wheel width before choosing among available 820-15 products or considering a radial equivalent, since construction changes and wider wheel setups can affect how the tire sits and clears the car.

Yes. The 1956 Imperial C73 V8 Custom uses the same 820-15 bias-ply tire size as the core fitment, so there is no separate original size to sort through for that covered sub-model.

With the size staying the same, the real decision becomes choosing the right version of 820-15 for the car’s purpose. A restoration-oriented Imperial may lean toward a traditional whitewall bias-ply, while a road-driven example may prompt a closer look at radial equivalents after checking wheel width, clearance, and the overall condition of the steering and suspension.

For the 1956 Imperial C73, 820-15 is the primary bias-ply tire size. It uses the older numeric sizing format common to the period and remains the traditional construction choice for owners who want the original style of fitment.

That matters because a bias-ply tire affects both the car’s appearance and the type of product choices available. The 820-15 range includes blackwall, narrow whitewall, and wide whitewall versions, so an owner can keep the period-style construction while tailoring the visual presentation to the car’s restoration level and intended road use.

Radial equivalents for 820-15 include 235R15 as the 80-series metric radial option, P235/75R15 as the P-metric 75-series choice, P255/70R15 as the P-metric 70-series choice, and 820R15 as the bias-look radial equivalent.

Each of those sizes approaches the original fitment in a slightly different way, so the decision is about more than matching rim diameter. A 6-8 inch rim-width range is associated with these equivalents, and it is smart to compare wheel width, overall tire dimensions, and vehicle clearance before moving from the original bias-ply format to any radial alternative.

Start by confirming the wheel diameter and actual wheel width on the car, then compare the radial equivalent size under consideration. For a 1956 Imperial C73 with an original 820-15 fitment, the equivalent choices include 235R15, P235/75R15, P255/70R15, and 820R15.

A construction change should also prompt a close look at steering clearance, fender clearance, suspension condition, and any past wheel or ride-height modifications. On a collector car, it is equally important to decide whether preserving a traditional bias-ply appearance matters more than using a radial format with a different sizing convention or a bias-look radial presentation.

Begin with the correct primary size, which is 820-15 on a 15-inch rim, then narrow the choice by construction and intended appearance. For this car, most selection decisions center on traditional bias-ply products in blackwall, narrow whitewall, or wide whitewall form.

Brand, tire series, wheel-width compatibility, and the car’s intended use all matter once the size is settled. A restoration-focused Imperial may call for a particular whitewall presence, while a regularly driven car may place more emphasis on setup verification and whether a radial equivalent should be considered after checking the wheel and chassis configuration.

The available 820-15 tires for a 1956 Imperial C73 include blackwall, narrow whitewall, and wide whitewall sidewall styles. That gives the car a broad range of visual directions, from a restrained darker sidewall to a more formal mid-1950s whitewall presentation.

Choosing among them depends less on fitment than on how the finished car should look. Wide whitewalls often suit a restoration-oriented luxury car very differently than blackwalls do, but it still helps to compare the exact tire series and wheel specifications so the final choice matches both the vehicle’s stance and its planned driving use.

The 820-15 size for the 1956 Imperial C73 is available from BFGoodrich, Firestone, US Royal, Universal Vintage Tire, and Avon. Those brands cover several classic bias-ply series as well as multiple sidewall presentations within the same primary size.

The best way to compare them is by looking at the combination of sidewall style, tire series, and wheel-width compatibility rather than treating the brand name alone as the deciding factor. On a large 1950s luxury car, appearance, intended use, and how closely the tire matches the car’s overall presentation are often the real points of comparison.

A period-style 1956 Imperial C73 usually starts with the original 820-15 bias-ply size. Staying with that numeric bias-ply format preserves the traditional look of the tire itself, and the available products allow the choice to shift between blackwall, narrow whitewall, and wide whitewall presentations.

The final decision should match the way the car is being restored and displayed, not just the size alone. If historical accuracy is especially important, it helps to compare the tire’s sidewall treatment with marque references, period photos, or restoration documentation so the visual result suits the car’s year and character.

Tire construction changes the visual impression of a restored 1956 Imperial C73 because bias-ply and radial tires do not present the same way on the car. The original 820-15 fitment is bias-ply, which aligns naturally with the vehicle’s mid-1950s proportions and traditional sidewall styling.

A radial equivalent may still be worth considering for road use, especially in a bias-look radial form such as 820R15, but the appearance should be judged carefully on the actual wheels. On a car with dramatic body lines and visible sidewall, details like profile, sidewall shape, and whitewall treatment can noticeably change the finished presentation.

Yes. Even though the primary size for a 1956 Imperial C73 is 820-15 on a 15-inch rim, aftermarket wheels, altered wheel widths, suspension work, ride-height changes, or brake conversions can all affect how that size or a radial equivalent fits the car.

A modified car should be checked at the wheel opening and through the steering range before settling on any tire. That is especially important when moving away from the original bias-ply setup, since a radial equivalent may use a different sizing convention and may place new emphasis on wheel width and fender or suspension clearance.

Before putting a 1956 Imperial C73 back on the road with new tires, inspect the wheels, valve stems, and overall wheel condition, then make sure the tires are properly mounted and inflated for their application. It also helps to check for any obvious steering or suspension wear that could affect how the car tracks.

A short collector-car shakedown should include watching for vibration, rubbing, pulling, or unusual clearance issues at full steering lock. Because older cars are often driven infrequently, it is wise to recheck pressure after the first few trips and keep an eye on sidewall condition, tread wear, and any signs of air loss.

Collector-car 820-15 tires should be maintained with regular pressure checks, visual inspections, and careful storage habits. Even when tread wear is low, older or low-use tires can still develop age-related issues such as cracking, flat spotting, sidewall damage, or slow air loss that deserve attention.

A 1956 Imperial C73 benefits from periodic inspection before every meaningful drive and after long storage periods. Keeping the car away from prolonged heat, direct sunlight, moisture, and ozone sources can help protect the tires, and any sign of bulges, cuts, persistent pressure loss, or unusual wear should be addressed before returning the car to road use.