1958 De Soto Tire Fitment Guide

1958 De Soto vehicles use three bias-ply sizes: 800-14, 850-14, and 900-14. The 800-14 size fits the LS 1 and LS 1-L-8 Firesweep, the 850-14 size is used across LS 1, LS 1-L-8 Firesweep, LS 2-H-8 Firedome, LS 3-H-8 Fireflite, and LS 3-S-8 Adventurer applications, and the 900-14 size is used on LS 2-H-8 Firedome and LS 3-H-8 Fireflite models. All three sizes mount on 14-inch wheels, with listed rim-width ranges of 5.00 to 6.00 inches for 800-14, 5.50 to 6.00 inches for 850-14, and 6.00 to 7.00 inches for 900-14.

That means the first step is identifying the model, not just the make and year. Even though all of these De Soto applications stay within the same wheel diameter, section width changes from size to size and the acceptable wheel-width range changes with it, so the right fitment depends on matching the tire to both the specific model and the actual wheel on the car.

On a 1958 De Soto tire, 800-14 is a numeric bias-ply size. The 8.00 designation refers to the tire’s nominal section width in the traditional numeric sizing system, and the 14 identifies the wheel diameter in inches. Within the 1958 De Soto range, 800-14 is used on LS 1 and LS 1-L-8 Firesweep applications and is offered in blackwall, narrow whitewall, and wide whitewall versions.

Modern buyers sometimes expect a metric code or a radial-style aspect ratio, but this earlier format works differently. If your De Soto is one of the models tied to 800-14, focus on preserving that correct numeric size, then choose the sidewall style that matches the look you want and confirm that the wheel falls within the listed 5.00- to 6.00-inch rim-width range.

No, 1958 De Soto models do not all use the same tire size. The 850-14 size appears across the entire model spread, but the 800-14 size is limited to LS 1 and LS 1-L-8 Firesweep applications, while the 900-14 size is limited to LS 2-H-8 Firedome and LS 3-H-8 Fireflite models. The Adventurer is associated with 850-14 in the listed range.

That variation matters because a full-size late-1950s De Soto can look very similar across nameplates at a glance, yet the correct tire may differ. If you are unsure whether you have a Firesweep, Firedome, Fireflite, or Adventurer, confirm the model identity first so you can narrow the choice to the right section width before moving on to sidewall style or brand preference.

The right choice for a 1958 De Soto depends on the model and wheel width, not on a bias-ply versus radial decision, because all listed options here are bias-ply 14-inch sizes. The 800-14 size is tied to LS 1 and LS 1-L-8 Firesweep applications, the 850-14 size spans the whole model range, and the 900-14 size is reserved for LS 2-H-8 Firedome and LS 3-H-8 Fireflite applications. Each size also carries its own approved rim-width range.

Choose by matching the car first, then matching the wheel. If you own an upper-line Firedome or Fireflite, for example, the larger 900-14 may be the appropriate direction when that model-specific fitment is required, while a Firesweep owner should stay within the 800-14 or 850-14 fitments tied to that model rather than selecting only by appearance.

1958 De Soto tires are available in several sidewall styles depending on size. The 800-14 size is offered in blackwall, narrow whitewall, and wide whitewall versions, while 850-14 and 900-14 are available in narrow whitewall and wide whitewall form. That gives owners flexibility to tune the visual character of the car while staying within a period-appropriate bias-ply construction.

Wide whitewalls are especially associated with the late-1950s American full-size look, so they suit many showroom-style restorations and high-visibility display cars. Narrow whitewalls create a slightly more restrained appearance, and blackwalls work best when a simpler presentation is preferred, but the most authentic choice for judging or a faithful restoration should always be checked against period photos, factory literature, or a De Soto marque specialist.

Two brands appear in the available 1958 De Soto tire range: BFGoodrich and Universal Vintage Tire. BFGoodrich covers all three sizes, offering 800-14, 850-14, and 900-14 bias-ply tires, while Universal Vintage Tire appears in the 800-14 size. Sidewall availability varies by brand and size, with the broadest mix found in 800-14.

For many buyers, the brand decision comes after the fitment decision. Once you confirm the right size for your De Soto model, compare the available sidewall treatments within that size and decide whether your priority is a specific late-1950s visual style, a blackwall presentation, or simply staying within the established bias-ply offerings tied to your particular application.

Rim-width requirements for 1958 De Soto tires depend on the size. The 800-14 size is listed for 5.00- to 6.00-inch rims, the 850-14 size is listed for 5.50- to 6.00-inch rims, and the 900-14 size is listed for 6.00- to 7.00-inch rims. All three sizes use a 14-inch rim diameter, but the acceptable wheel width increases as the tire section size increases.

That is why wheel diameter alone is not enough when choosing a replacement tire. If your car has its original wheels, they may already align with the proper size for the model, but restored or swapped cars deserve a closer look, since moving from one listed tire size to another can push the wheel outside the approved width range even when the rim still measures 14 inches.

The available 1958 De Soto tire listings do not show mixed tube-type and tubeless markings within these sizes, and no tube-specific designation appears in the size lines shown here. That keeps the focus on matching the correct numeric size, sidewall style, and rim-width range rather than sorting through multiple tube-status versions within the same size.

Wheel condition still matters on a late-1950s car. Before mounting new tires on a 1958 De Soto, inspect the wheels carefully for rust, pitting, bead-seat damage, and valve-stem condition, and confirm the exact setup you plan to run so the mounted assembly matches both the tire manufacturer’s specifications and the car’s intended restoration or driving use.

Original 1958 De Soto wheels can share the same 14-inch rim diameter across all three listed tire sizes, so diameter compatibility is consistent throughout the range. Width compatibility is where the real difference lies: 800-14 is listed for 5.00 to 6.00 inches, 850-14 for 5.50 to 6.00 inches, and 900-14 for 6.00 to 7.00 inches.

That means a wheel that accepts one listed size is not automatically suitable for every other listed size. If your De Soto has its factory wheels, the model-specific tire size is usually the safest reference point; if the car has replacement wheels or a mixed set, measure the wheel width before choosing between 800-14, 850-14, and 900-14.

A stored 1958 De Soto should be kept in a cool, dry, dark space away from direct sunlight, electric motors, welders, furnaces, and other ozone-producing equipment that can age rubber. Because the listed tires for 1958 De Soto are bias-ply designs, they can develop temporary flat-spotting more readily during long periods of inactivity than a modern radial. Clean concrete is better than damp dirt or gravel, and stable air pressure should be maintained while the car sits.

If the car will rest for months, move it occasionally so the weight is not always on the same footprint, or support it in a way that reduces sustained load without leaving the suspension hanging unnaturally. A breathable car cover and routine pressure checks help preserve both the tires and the overall presentation of a collector De Soto during off-season storage.

Tires on a 1958 De Soto are usually judged by age and condition more than by mileage, since many collector cars are driven only occasionally. A good rule is to begin careful evaluation once a tire reaches about five to seven years of service and to treat around ten years as a serious replacement point regardless of tread depth. The DOT date code on the tire helps establish age.

That approach matters because a De Soto can wear very little tread while the rubber still hardens, cracks, or loses resilience over time. If the car spends long periods indoors and sees only short local drives, the tires may still look presentable, but age, sidewall condition, and overall integrity should guide replacement decisions more than outward appearance alone.

Tires on a 1958 De Soto should be inspected before every drive and again before any longer outing or highway trip. Look for sidewall cracking, tread separation signs, cuts, bulges, weathering around the bead area, and pressure loss, and make sure the spare is checked on the same schedule. Valve stems deserve attention as well because a collector car often sits longer between uses than a modern daily driver.

Frequent inspection is especially important on a heavy late-1950s full-size car, where a problem may not reveal itself until the vehicle is already moving at speed. A quick pre-drive walkaround takes very little time and can catch the kinds of age-related issues that matter more on a hobby vehicle than simple tread wear does.

A 1958 De Soto LS 1 would have been a bias-ply application in period, which matches the construction type offered here for the year. Within the listed fitments for the LS 1, both 800-14 and 850-14 appear, so the correct choice for a particular car should be matched to its exact configuration, wheel width, and factory literature rather than assumed from year alone. No specific original-equipment brand should be presumed solely from the replacement choices available today.

That makes the LS 1 a good example of why restoration tire selection should combine fitment records with car-specific verification. If you are preparing a judged car, compare your current wheel and trim presentation with period brochures, surviving original cars, and De Soto club references so the selected size and sidewall style align with how your particular example would have appeared when new.

Correct tire fitment does matter when showing a 1958 De Soto, especially in events that reward authenticity. Judges and knowledgeable enthusiasts often notice whether the tire size matches the model, whether the construction matches the era, and whether the sidewall treatment suits a late-1950s American full-size car. A visibly incorrect section width or an off-era sidewall look can stand out quickly on a dramatic Forward Look body.

For a show car, the goal is not only mechanical fit but visual credibility. A wide whitewall often looks more natural on a period-correct presentation than a blackwall, but exact expectations can vary by event, so owners chasing concours-level accuracy should review the rules of the judging body and cross-check with marque-specific restoration guidance before making the final selection.

For a 1958 De Soto, the BFGoodrich narrow whitewall and wide whitewall options share the same underlying bias-ply construction within a given size, but they change the visual emphasis of the car. In 800-14, 850-14, and 900-14 fitments, the available BFGoodrich whitewall choices include 1.00-inch narrow whitewall and 2.25-inch wide whitewall versions. Load and pressure figures stay the same within each size, so the difference is chiefly appearance rather than basic fitment category.

That makes the choice largely a restoration-style decision. Owners aiming for a bold late-1950s showroom look often prefer the wider band, while those wanting a more restrained appearance may lean toward the narrower whitewall; either way, the correct approach is to choose the proper tire size for the model first and then select the sidewall treatment that best matches the car’s intended presentation.

Properly matched and well-maintained 1958 De Soto tires can be used for normal road driving, but the available fitments here are all bias-ply designs and should be treated with the driving expectations appropriate to that construction. No speed-rating markings are shown for these sizes in the available listings, so the safer approach is to respect the capabilities of both the tires and the car itself. On a big late-1950s De Soto, steering feel, braking distance, suspension condition, and age-related component wear can matter as much as the tire choice.

Highway use starts with condition, inflation, and realistic speed habits rather than with a simple yes-or-no label. Before taking a collector De Soto onto faster roads, confirm that the tires are fresh, properly inflated, and free from age damage, and remember that even a newly restored car still behaves like a 1958 automobile rather than a modern sedan.

Inflation pressure on a 1958 De Soto should be set by the vehicle’s factory guidance for the application and checked against the tire’s own maximum load-and-pressure information rather than copied from another size. The available 800-14 tires list 1620 pounds at 32 psi, the 850-14 tires list 1740 pounds at 32 psi, and the 900-14 tires list 1860 pounds at 32 psi. Those figures describe the tire’s rated capacity point, not automatically the everyday running pressure for every De Soto model.

Use the owner’s manual or marque-correct service information to establish the recommended operating pressure for your specific model and loading conditions, then verify that your chosen tire size aligns with that application. Keeping pressure appropriate to the car helps preserve ride quality, steering response, and tread life while avoiding the common mistake of treating the sidewall’s maximum figure as the universal cold inflation target.

Before a longer drive in a 1958 De Soto, inspect each tire for cracks, cuts, bulges, embedded debris, uneven wear, and any sign of age-related separation. Check cold inflation pressures, confirm the spare is serviceable, and look closely at the valve stems and wheel condition. Since these De Soto fitments are tied to specific model applications, it is also wise to confirm that all four road tires are the same correct size for the car.

A longer trip in a late-1950s full-size car calls for a broader mechanical check as well, including brakes, cooling system, steering, and fluids. Tire condition is only one part of roadworthiness, but it is one of the easiest things to verify before departure and one of the most important for a heavy collector car that may spend much of its life parked between outings.