1958 Mercury Tire Fitment Guide

1958 Mercury vehicles use two tire sizes: 800-14 and 850-14. The 800-14 size fits the broad Mercury range, including the general "All Models Except" grouping as well as Convertible and Wagon models. The 850-14 size is limited to 1958 Mercury Convertible and Wagon applications. Both sizes mount on 14-inch rims, and the available rim-width range shown in current products is 5.00 to 6.00 inches for 800-14 and 5.50 to 6.00 inches for 850-14.

That means a buyer with a sedan, hardtop, or other non-convertible, non-wagon Mercury should focus on 800-14 first. A 1958 Mercury Convertible or Wagon owner should verify whether the car is being restored to the standard 800-14 fitment or the larger 850-14 fitment before choosing a tire. Checking the actual wheel width on the car is the smart next step, especially if the wheels have been changed at some point in the car’s life.

On a 1958 Mercury, 800-14 is a numeric bias-ply tire size. The "800" portion refers to the tire’s nominal section width in the older numeric sizing system, and the "14" means the tire is built for a 14-inch wheel. It is not a modern metric radial size, so it should be read as a period bias-ply designation rather than compared directly to a P-metric tire by the code alone.

That older size format matters because it helps explain why 800-14 remains the baseline choice across most of the 1958 Mercury range. When comparing products in this size, the more meaningful differences are sidewall appearance, rim-width compatibility, and whether the tire suits the kind of restoration you are doing. For most buyers, the code confirms they are shopping in the correct vintage size family before they narrow the choice further.

No, all 1958 Mercury models do not use the same tire size. Most of the Mercury lineup uses 800-14, but Convertible and Wagon models can also use 850-14. That larger size does not apply across the full range, so the model grouping matters before a tire is selected. Both sizes are bias-ply and both fit 14-inch rims, but they are not interchangeable as a blanket year-and-make choice.

The practical takeaway is that a buyer should identify the car as a standard Mercury passenger model or as a Convertible or Wagon before moving on to product selection. That is especially important for restoration work, where body-style-specific sizing can affect the finished look as much as basic fitment. If the car has had wheel or suspension changes over the years, checking the current wheel width and the size already on the car can help avoid ordering the wrong size family.

For most 1958 Mercury vehicles, 800-14 is the correct starting point because it applies across the broad Mercury model range. The 850-14 size is reserved for 1958 Mercury Convertible and Wagon models, so it should only be considered if you own one of those body styles. Both sizes are offered as bias-ply tires, which keeps the decision centered on correct application within the model range rather than choosing between bias-ply and radial construction.

A buyer with a Convertible or Wagon should think in terms of body-style-specific fitment and visual stance, while a buyer with any other 1958 Mercury should stay with 800-14 unless the car has a known special fitment history. Because both sizes fit 14-inch wheels, the next check is wheel width, not just wheel diameter. Matching the size to the exact model keeps the car closer to period appearance and avoids forcing a broader tire onto a wheel that may not suit it.

1958 Mercury tires are available with several sidewall treatments, depending on size. In 800-14, current offerings include blackwall, narrow whitewall, and wide whitewall versions. In 850-14, the available choices are narrow whitewall and wide whitewall. That gives owners room to match the visual character of the car, from understated blackwall styling to the more prominent whitewall look associated with many late-1950s American cars.

For a period-correct restoration, whitewall choice often matters almost as much as size because it changes the car’s overall presentation. A wide whitewall usually delivers the strongest late-1950s visual effect, while a narrow whitewall or blackwall may suit a more restrained build or a driver-quality car. The best approach is to compare the tire sidewall style against period photos, factory literature, and the trim level of the specific Mercury you are restoring.

Two brands currently cover 1958 Mercury tire applications in the listed sizes: BFGoodrich and Universal Vintage Tire. The 800-14 size is available from both BFGoodrich and Universal Vintage Tire, while 850-14 is offered in BFGoodrich versions. All of the listed choices are bias-ply tires, which keeps them in step with the construction style expected on a 1958 full-size American car.

Brand choice on a 1958 Mercury often comes down to the exact size needed and the sidewall look you want to achieve. Buyers shopping for 800-14 have the broadest brand and appearance spread, while 850-14 buyers are choosing within a narrower range because that size is tied to specific Mercury body styles. Once the correct size is settled, comparing the available whitewall presentation is usually more useful than chasing brand name alone.

1958 Mercury tire rim-width requirements depend on the size selected. The 800-14 size is matched to wheels in the 5.00- to 6.00-inch width range, while 850-14 is matched to 5.50- to 6.00-inch widths. Both sizes use 14-inch rim diameter, but the acceptable wheel width is not identical between them. That difference is important because width, not just diameter, affects how properly the tire sits on the wheel.

A buyer choosing 800-14 has slightly more flexibility on narrower 14-inch wheels than a buyer choosing 850-14. If a 1958 Mercury has replacement wheels, widened stock wheels, or uncertain wheel history, measuring the actual wheel before selection is worth the time. Staying within the listed width range helps preserve the intended profile and avoids forcing a larger tire onto a wheel that is too narrow for it.

Both tire sizes used on 1958 Mercury vehicles mount on 14-inch wheels, so they share the same rim diameter requirement. That means original 14-inch Mercury wheels are in the right diameter family for either 800-14 or 850-14. The remaining question is wheel width, because 800-14 fits a 5.00- to 6.00-inch range while 850-14 calls for 5.50 to 6.00 inches.

In practice, many original wheels can stay in service if they are structurally sound and fall within the correct width range for the tire selected. Convertible and Wagon owners considering 850-14 should confirm that their wheels meet the narrower width window for that size before assuming both sizes will work equally well. It is also wise to inspect wheel condition, bead-seat integrity, and prior repairs on any original late-1950s wheel before refitting fresh tires.

A stored 1958 Mercury should be kept in a cool, dry, dark space away from direct sunlight, electric motors, furnaces, welders, and other ozone-producing sources that accelerate rubber aging. Because the available 1958 Mercury sizes are bias-ply tires, they are more prone to temporary flat-spotting after long static periods than modern radials. Clean concrete is preferable to bare earth, and maintaining proper inflation during storage helps the tire keep its shape.

If the car sits for extended periods, rolling it occasionally or supporting it in a way that reduces long-term load on the tires can help limit flat spotting. Tire covers are useful when the garage has windows or frequent light exposure. A collector Mercury that is stored well will usually drive smoother on its first outings and will show less cosmetic sidewall aging over time.

Tires on a 1958 Mercury should be judged more by age and condition than by mileage, because collector cars often accumulate very few miles while the rubber continues to age. A sensible rule is to evaluate tires closely once they are five to seven years old and to treat around ten years as the point where replacement deserves serious consideration, even if the tread still looks healthy. The DOT date code on the tire is the quickest way to determine age.

That age-based approach matters on a full-size 1958 Mercury because a large, heavy collector car places real demands on its tires even during occasional use. Cracking, hardening, loss of ride quality, and changes in how the tire holds pressure are often more important warning signs than tread depth alone. Owners who drive only to shows sometimes overlook tire age, but time remains one of the main factors in collector-tire safety.

Tires on a 1958 Mercury should be inspected before every drive, with a more deliberate check before any longer outing. Look for sidewall cracking, weather checking, bulges, cuts, embedded debris, uneven tread wear, and any sign that the car has been parked on an underinflated tire. Pressure should be checked regularly with an accurate gauge rather than judged by appearance, especially on bias-ply tires that can visually mask small pressure changes.

A longer inspection interval is not a good habit on a collector Mercury because weeks or months may pass between drives. Cars that sit can develop age-related issues without obvious mileage wear, and any original or older valve hardware deserves close attention during pressure checks. Catching a small crack or air-loss issue in the garage is much better than discovering it once the car is loaded for a highway trip.

A 1958 Mercury Convertible & Wagon would have been fitted in period with bias-ply tires, because bias-ply construction was still standard American practice for the era. Within the current fitment range, those models can use either 800-14 or 850-14, with 850-14 standing apart as a body-style-specific size for the Convertible and Wagon grouping. No original-equipment brand should be assumed from fitment alone, since market, trim, and prior restoration choices can all affect what is seen on a surviving car today.

For an authenticity-minded restoration, the key factors are the correct size for the specific body style, bias-ply construction, and a sidewall treatment that matches the look your car would have carried when new. Factory literature, period photos, and Mercury marque specialists are the best way to refine that choice further. That research is especially worthwhile on wagons and convertibles, where the larger optional size can influence both stance and judged originality.

Correct tire fitment matters on a 1958 Mercury because show judging often considers whether the car presents the proper size, construction type, and sidewall appearance for its year and body style. On a late-1950s Mercury, using a size outside the accepted range for the model or using a sidewall style that clashes with period presentation can draw attention quickly. For Convertible and Wagon models, choosing between 800-14 and 850-14 is part of that authenticity discussion.

The higher the level of judging, the more important those details become. A local cruise-in may never question the difference, but marque-focused events often reward cars that get the visual details right, including tire profile and whitewall treatment. Owners preparing a judged car should compare the intended tire against original sales material and consult the relevant Mercury club or judging manual before finalizing the setup.

Within 800-14 fitment for the 1958 Mercury, BFGoodrich and Universal Vintage Tire differ mainly in the specific sidewall offerings shown and in how much published specification detail accompanies the tire. BFGoodrich 800-14 options include blackwall, narrow whitewall, and wide whitewall versions, with listed load capacity of 1620 pounds at 32 psi and a 5.00- to 6.00-inch rim-width range. Universal Vintage Tire appears in 800-14 as a wide whitewall bias-ply option, giving buyers another visual path in the same size family.

For restoration purposes, that means the choice is often less about basic fitment and more about the appearance you want on the finished car. Someone restoring a specific showroom look may focus first on whitewall width, while another owner may want a more subdued blackwall presentation that fits the era but changes the car’s personality. Comparing the sidewall look against period Mercury imagery is usually the most productive way to separate otherwise similar bias-ply options.

1958 Mercury tires can be used for highway driving when they are in good condition, properly fitted, correctly inflated, and matched to the car’s intended use. The listed 800-14 and 850-14 options are bias-ply tires, so they deliver the road manners typical of the period rather than the feel of a modern radial. On a large late-1950s Mercury, the condition of the brakes, steering, suspension, and wheel alignment often matters just as much as the tire itself at normal highway speeds.

A buyer should think of these tires as part of a complete vintage-car system rather than a standalone upgrade. Fresh, properly selected bias-ply tires can be entirely appropriate for regular collector use, but they should be driven with the expectations that come with a 1958 full-size car. Smooth inputs, conservative speeds for conditions, and a thorough mechanical inspection are all part of using an older Mercury responsibly on modern roads.

Available load-and-pressure figures differ by size on 1958 Mercury tires, so pressure should never be copied blindly from one size to another. The listed 800-14 BFGoodrich tires show a maximum load capacity of 1620 pounds at 32 psi, while the listed 850-14 BFGoodrich tires show 1740 pounds at 32 psi. Those figures are tire ratings, not a blanket factory recommendation for every Mercury application or loading condition.

The best practice is to start with the original Mercury owner’s literature or service information for the vehicle’s intended operating pressure, then compare that with the reproduction tire’s construction and rating guidance. Convertible and Wagon owners should be especially careful not to transfer assumptions between 800-14 and 850-14 setups. Pressure affects ride, tread wear, and steering feel, so getting it right is part of making a full-size 1958 Mercury behave as intended.

Before a longer drive in a 1958 Mercury, inspect every tire for visible cracks, cuts, bulges, weathering, and uneven wear, then verify pressure with the tires cold. Check that the spare is serviceable and inflated, and make sure the wheel hardware and valve stems are in good condition. Because Convertible and Wagon models may use either 800-14 or 850-14, confirm that all four road tires match the intended size and that the wheels are appropriate for that fitment.

A longer trip is also the right time to think beyond the tires themselves. A heavy late-1950s Mercury should have its brakes, cooling system, steering, and suspension checked before extended road use, especially if it has been sitting. The tire inspection is the first layer of confidence, but a complete pre-drive review is what turns a collector-car outing into a reliable trip rather than a roadside repair.