1948 De Soto Tire Fitment Guide

1948 De Soto vehicles in the Custom and Deluxe range use three bias-ply sizes: 700-15, 760-15, and 650-16. The two 15-inch sizes mount on 15-inch rims, while 650-16 mounts on a 16-inch rim. Where published fitment details are available, 700-15 uses 5.00-5.50 inch rims, 760-15 uses 5.50-6.00 inch rims, and 650-16 uses 4.50-5.00 inch rims.

The practical takeaway is that year and make alone are not enough for a 1948 De Soto. You need to confirm which wheel diameter is actually on the car first, then match the tire size to that wheel. If the car has been restored or altered over the years, the current wheel setup may matter more than the badge on the fender.

On a 1948 De Soto, 700-15 is a numeric bias-ply size. The 700 refers to the tire's nominal section width in the older numeric system, and the 15 indicates that the tire fits a 15-inch wheel. It is not a modern metric radial code, so it should be interpreted within the period bias-ply sizing system used on late-1940s American cars.

That matters because a 700-15 should be compared with other vintage numeric sizes, not with a modern P-metric tire by appearance alone. If your De Soto currently wears 15-inch wheels and you are trying to preserve a correct late-1940s look, 700-15 is one of the era-appropriate sizes to evaluate before narrowing down sidewall style and brand.

No. The 1948 De Soto Custom and Deluxe range spans more than one tire size, including 700-15, 760-15, and 650-16. That means there is not a single universal replacement size across every 1948 De Soto covered here, even though all of them use bias-ply construction.

For a buyer, that means the model name is only the starting point. The real confirmation point is the wheel and tire size your particular car carries, especially on a postwar car that may have had wheels swapped during restoration or long-term ownership. Checking the wheel diameter and the existing sidewall marking before you choose a replacement helps avoid unnecessary backtracking.

1948 De Soto tires are available in several period-style sidewall treatments depending on size. The 700-15 range includes blackwall and wide whitewall options, 760-15 includes narrow whitewall and wide whitewall options, and 650-16 includes blackwall and wide whitewall versions. All of these are bias-ply offerings, so the visual difference comes from sidewall treatment rather than a construction change.

That gives you room to tune the car's appearance without stepping outside the period feel of a late-1940s De Soto. Blackwalls tend to suit a more restrained or utility-minded presentation, while whitewalls deliver the fuller postwar American look many restorers want. If show accuracy matters, compare the whitewall width and style to period photos or club guidance for your exact body style and market.

Several established brands cover 1948 De Soto sizes. The 700-15 size is available from Firestone, BFGoodrich, and STA; 760-15 is available from BFGoodrich, Coker Classic, and Universal Vintage Tire; and 650-16 is available from BFGoodrich, Coker Classic, Firestone, and Garfield. All of the listed choices use bias-ply construction, keeping them aligned with the character of the period.

Brand choice on a 1948 De Soto usually comes down to sidewall appearance, preferred tread style, and whether you want a marque with long collector-car recognition. Since the available brands differ by size, it helps to settle the correct wheel diameter first. Once that is done, you can compare the visual character of the available tires rather than sorting through brands that do not apply to your car.

In 700-15 for the 1948 De Soto, both Firestone and BFGoodrich offer classic bias-ply tires, and load-rated examples carry 1700 pounds at 32 psi. Firestone appears in both blackwall and 4.125-inch whitewall form, while BFGoodrich appears in a 4.125-inch wide whitewall version. Published rim-width guidance for those rated examples falls in the 5.00-5.50 inch range.

The choice between them is less about fitment than about visual preference and brand character. If you want a blackwall in 700-15, Firestone is one route within the available options; if a broad whitewall is the goal, both names participate in that period-correct look. Once you've confirmed 700-15 is the right size for your De Soto, the sidewall presentation often becomes the deciding factor.

Rim-width guidance for 1948 De Soto tires depends on the size. The 700-15 size is paired with 5.00-5.50 inch rims on listed examples, 760-15 is paired with 5.50-6.00 inch rims, and 650-16 is paired with 4.50-5.00 inch rims. Those dimensions should be treated as size-specific rather than interchangeable across the whole 1948 De Soto range.

That means a tire choice should follow the wheel already on the car, not the other way around. Before replacing anything, measure or confirm the actual rim and match it to the published range for the tire size you intend to run. If your car has older restored wheels or mixed parts from past ownership, verifying the wheel itself is especially worthwhile.

Not across the full 1948 De Soto range, because all three sizes do not share the same rim diameter. The 700-15 and 760-15 tires both require 15-inch wheels, while 650-16 requires a 16-inch wheel. That separates the fitment question into two wheel families rather than one interchangeable group.

If your De Soto already has 15-inch wheels, you can compare the two 15-inch sizes more directly, while still checking the wheel width against the tire's published range. A car equipped with 16-inch wheels needs to stay within the 16-inch size family unless the wheels themselves are changed. Confirming wheel diameter first is the fastest way to narrow the right path.

A stored 1948 De Soto should be kept in a cool, dry space away from direct sunlight, electric motors, battery chargers, furnaces, and other ozone-producing equipment that can age rubber. Bias-ply tires also benefit from maintaining proper inflation during storage and from periodic rolling to change the tire's loaded position. Clean, dry floors and stable temperatures help reduce avoidable sidewall and tread aging.

Long static storage can encourage flat-spotting in bias-ply tires more readily than many owners expect, especially on a heavy postwar sedan. If the car will sit for months, occasional movement or properly placed stands can help reduce stress on the casing. It is also smart to inspect the spare under the same conditions, since collectors often forget the fifth tire until they actually need it.

Tires on a 1948 De Soto should be judged more by age and condition than by mileage alone, because collector cars often see limited annual use. A good rule is to start evaluating tires closely once they reach the five- to seven-year range and to consider replacement as they approach about ten years, even if tread depth still looks serviceable. The DOT date code on the tire helps establish age.

That approach matters because a lightly driven vintage car can wear out rubber chemically before it wears out the tread mechanically. Sidewall cracking, hardening, repeated air loss, and visible distortion are more useful warning signs than odometer miles on a hobby car. If the De Soto is used for tours or longer trips, staying ahead of age-related replacement is usually the wiser choice.

Tires on a 1948 De Soto should be inspected before every drive and again before any longer road trip. Look for sidewall cracking, cuts, bulges, uneven wear, exposed cords, and any change in how well the tire holds pressure. Because these are vintage-style bias-ply tires, even a car that is driven sparingly deserves regular inspection rather than a calendar-only approach.

A brief walk-around before moving the car can catch most problems early. Check inflation with an accurate gauge when the tires are cool, and pay attention to valve stems and the spare as well as the four road tires. If the car starts to pull, shimmy, or feel different from its normal bias-ply behavior, stop and inspect before assuming it is just old-car character.

A 1948 De Soto Custom & Deluxe would have been a bias-ply car when new, which matches the sizes used here: 700-15, 760-15, and 650-16. Those are all period-style numeric bias-ply sizes, and the available blackwall and whitewall offerings fit the visual language of the late 1940s. No single original-equipment brand should be assumed without checking model-specific factory literature or marque references.

For restoration work, the most important points are matching the correct size family and keeping the construction era-correct. If your goal is exact historical accuracy, compare your car's current wheel diameter and surviving records with period brochures, factory manuals, or De Soto club sources. That is especially helpful when a car has passed through several owners and may no longer wear its original wheel setup.

Correct tire fitment does matter when showing a 1948 De Soto, especially in events that evaluate authenticity closely. Judges and experienced marque enthusiasts often notice the overall size, the bias-ply construction, and whether the sidewall style suits the period look of the car. A mismatched wheel diameter or an obviously modern-looking replacement can change the car's stance and visual credibility.

For that reason, choosing between blackwall, narrow whitewall, and wide whitewall should be done with the intended presentation in mind. A touring car built for enjoyment may justify a different visual choice than a concours-focused restoration. If the event has strict standards, consult the judging rules or a De Soto specialist before finalizing the tire style, since show expectations can vary by club and class.

In 760-15 for the 1948 De Soto, BFGoodrich offers both a 3.375-inch wide whitewall and a 1.00-inch narrow whitewall, while Coker Classic offers a 3.00-inch wide whitewall version. Load-rated examples in this size carry 1710 pounds at 32 psi, and the published rim-width range for those rated examples is 5.50-6.00 inches. All of them remain within the same period-style bias-ply category.

That makes the comparison mainly a visual and restoration decision rather than a fitment split. If you are trying to echo a fuller postwar whitewall look, the broader whitewall options will likely be the natural direction; if you prefer a cleaner, less ornate presentation, the narrow whitewall changes the car's appearance noticeably while staying within the 760-15 size. Confirm the wheel width before making the final call.

1948 De Soto tires in the available sizes are vintage-style bias-ply products, and they can be used for normal road driving when they are the correct size, properly inflated, and in sound condition. No speed ratings are specified here for these sizes, so safe highway use depends heavily on matching the tire to the wheel, maintaining the tire correctly, and respecting the broader limits of a late-1940s automobile.

In real-world driving, a 1948 De Soto's braking, steering, suspension condition, and overall mechanical state are often more important than chasing modern-speed expectations. A well-sorted postwar car on fresh, correctly fitted tires can be enjoyable on secondary roads and reasonable highway stretches, but it should still be driven with the habits appropriate to its era. Tire condition is part of that equation, not the whole of it.

Several listed 1948 De Soto tires include load-and-pressure figures that provide a useful product reference point. In 700-15, rated examples carry 1700 pounds at 32 psi; in 760-15, rated examples carry 1710 pounds at 32 psi; and in 650-16, rated examples carry 1580 pounds at 32 psi. Those figures belong to those specific tire sizes and products and should not be transferred casually from one size to another.

For actual use on the car, compare the tire maker's rating with the original De Soto owner's literature or service information for factory inflation guidance. Vintage vehicles can respond noticeably to even small pressure changes in ride and steering feel, especially with bias-ply construction. Starting with the correct size-specific range and then confirming against the vehicle's own recommended settings is the best approach.

Before a longer drive in a 1948 De Soto, inspect each tire for cracking, cuts, bulges, punctures, uneven wear, and proper cold inflation. Check the spare, the valve stems, and the wheel itself, and make sure the tire size on the car matches the wheel diameter it is mounted on. On a collector vehicle of this age, tire readiness should be treated as one part of a broader roadworthiness check.

A smart pre-trip routine also includes looking at the car's brakes, steering, suspension, wheel bearings, and fluid condition so the tires are not asked to compensate for other problems. Bias-ply cars telegraph issues differently than modern vehicles, so familiarizing yourself with how the De Soto normally feels before a trip is helpful. If anything feels newly vague, harsh, or unstable, sort it out before adding miles.