1931 Cadillac Tire Fitment Guide

1931 Cadillac vehicles use five different tire sizes across three model families. The V8 uses 650-19 and 700-18, the V12 uses 700-19 and 750-18, and the V16 uses 750-19. Rim diameters are split between 18-inch and 19-inch applications, so these are not interchangeable across the full 1931 Cadillac range. Where rim-width guidance is listed, 650-19 appears on 3.25-3.50-inch rims, 700-18 on 3.75-4.00-inch rims, 700-19 on 3.75-4.00-inch rims, 750-18 on 4-inch Firestone applications or 6.00-6.50-inch Deka truck applications, and 750-19 on 4-inch rims.

The practical takeaway is that year and make alone are not enough for a 1931 Cadillac. You need to identify the engine-series family first, then confirm whether the car is on 18-inch or 19-inch wheels before choosing a tire. That matters especially on restored cars, where wheel changes can occur over time. Once the size is confirmed, the remaining choice is usually sidewall appearance and brand rather than a switch between modern radial and vintage bias-ply construction.

On a 1931 Cadillac, 700-19 is a numeric bias-ply tire size. The 700 designation refers to the nominal section-width class, traditionally read as 7.00 inches, and the 19 identifies the wheel diameter in inches. It is not a modern metric code and it does not state an aspect ratio the way later radial sizes do. Within the 1931 Cadillac line, 700-19 is used on the V12 and mounts on a 19-inch rim, with listed rim-width guidance of 3.75 to 4.00 inches on certain products.

That older numeric format matters because it guides you toward period-correct sizing language when matching a pre-war Cadillac. A buyer looking at 700-19 should think in terms of original-style bias-ply proportions, wheel diameter, and sidewall presentation rather than trying to translate it directly into a modern passenger-car metric equivalent. If your car is a V12, the next step is to verify whether it actually wears the 19-inch setup or the alternate 18-inch V12 fitment before selecting a specific tire.

No, 1931 Cadillac models do not share one universal tire size. The V8 uses either 650-19 or 700-18, the V12 uses either 700-19 or 750-18, and the V16 uses 750-19. Every listed fitment is a bias-ply tire, but the sizes are tied to specific model families and wheel diameters. That means a tire that fits a V8 cannot be assumed to fit a V12 or V16 simply because the cars share the same year and make.

For owners and restorers, that changes the research process. You should start with the model family and then verify the wheel diameter on the car itself, especially if the vehicle has had wheels or chassis components changed during earlier restoration work. Once that foundation is settled, choosing among available products becomes much easier because the remaining variables are mostly brand, sidewall style, and the exact look you want for touring, local driving, or show presentation.

1931 Cadillac tires are available in blackwall, wide whitewall, and double-whitewall styles depending on size. Blackwall appears across all five sizes. Wide whitewall options are offered in 750-18, 750-19, 650-19, and 700-18, while double-whitewall versions appear in 700-19, 750-18, 750-19, and 700-18. Those choices let owners tailor the visual character of a pre-war Cadillac without changing the underlying bias-ply construction or wheel diameter required by the car.

The right sidewall style usually comes down to how the car is being presented. A blackwall often suits a more restrained factory look or a formal body style, while whitewall treatments can emphasize the scale and elegance that many 1931 Cadillacs are known for. If authenticity for a specific body, delivery market, or judging standard matters, it is wise to compare the tire choice against period photos, club references, and the car's existing restoration theme before settling on a sidewall treatment.

Three brands appear across the 1931 Cadillac sizes covered here: Firestone, Lester, and Deka. Firestone has the broadest coverage, appearing in every listed size. Lester appears in 700-19 and 650-19, while Deka appears in 750-18. Brand availability is size-specific, so the model and wheel diameter you confirm first will narrow which names are actually relevant for your particular 1931 Cadillac.

That brand split matters because a V16 owner looking at 750-19 has a different set of choices than a V8 owner using 650-19 or 700-18. In practical terms, the buyer should identify the correct size first, then compare how each brand presents the tire visually and dimensionally within that size. On pre-war luxury cars, the brand matters less than matching the correct size, era-appropriate bias-ply construction, and sidewall style that complements the restoration.

On 1931 Cadillac fitments where both appear, Firestone Balloon and Firestone Classic Bias Ply are offered in the same numeric size but differ in presentation details and, in some cases, listed measurements such as weight and rim-width guidance. In 700-18, for example, both series appear as bias-ply tires, with Firestone Balloon versions listed in blackwall, wide whitewall, and double-whitewall styles and a 3.75-4.00-inch rim-width range, while a Firestone Classic Bias Ply blackwall is also offered. In 700-19 and 650-19, the same pattern appears, with Balloon and Classic Bias Ply versions sharing size but not always the same sidewall choices.

For a 1931 Cadillac owner, the practical difference is usually less about fitment and more about how closely the tire's look matches the car's restoration direction. If you already know the correct size, compare the series within that size for sidewall style, listed rim-width guidance where given, and the overall appearance you want on the car. That is especially worthwhile on a pre-war Cadillac, where the tire's sidewall treatment strongly influences the finished stance and period feel.

Rim-width guidance on 1931 Cadillac tires varies by size and sometimes by product within the same size. 650-19 is listed with a 3.25-3.50-inch range on certain Firestone Balloon products, 700-18 with 3.75-4.00 inches, 700-19 with 3.75-4.00 inches, and 750-19 with 4 inches. The 750-18 size is the notable exception because Firestone passenger-car versions are listed for 4-inch rims, while the Deka truck-style version is listed for 6.00-6.50-inch rims.

That makes wheel verification especially important before choosing a 750-18 tire for a 1931 Cadillac V12. On the other sizes, the guidance is more straightforward and lines up with traditional passenger-car applications. Owners working with original wheels, restored rims, or custom-built replacements should compare the actual wheel measurement against the intended tire's approved rim-width range. Doing that early helps avoid choosing a casing style that may be visually or mechanically mismatched to the wheel already on the car.

Original 1931 Cadillac wheels cannot be assumed to work with all listed tire sizes because the year uses both 18-inch and 19-inch rim diameters across different model families. A V8 may use either 650-19 or 700-18, a V12 may use either 700-19 or 750-18, and the V16 uses 750-19. Even where two sizes belong to the same model family, they are tied to different wheel diameters rather than simply being alternate tread or sidewall choices on the same rim.

For that reason, the first check is wheel diameter, not just the body or engine designation on the car. After that, compare the intended tire's rim-width guidance to the actual wheel in use, especially if the car has been restored over several decades or fitted with replacement wheels. Pre-war Cadillacs often survive with long histories of maintenance and parts swapping, so a quick physical confirmation of the wheel can prevent expensive mistakes and keep the finished fitment visually correct.

A 1931 Cadillac should be stored in a cool, dry, dark environment with the tires kept away from direct sunlight, electric motors, battery chargers, and other ozone-producing sources. Because every listed fitment is bias-ply, prolonged static storage can encourage flat-spotting and sidewall aging more readily than many later radial designs. Clean floors, stable temperatures, and correct inflation help reduce stress on the casing while the car is parked for long periods.

Owners who store a 1931 Cadillac for the season should move the car periodically if practical, or use stands in a way that follows safe chassis-support practices without leaving the suspension in an unnatural state for years at a time. It is also smart to check the spare during storage, since pre-war touring confidence often depends as much on the spare's condition as the four tires on the ground. Good storage habits preserve both appearance and service life.

Tires on a 1931 Cadillac should be judged primarily by age and condition rather than mileage. Collector vehicles often accumulate very few miles, yet the rubber can still age out from time, storage environment, heat cycling, and inactivity. A sensible rule is to begin evaluating tires closely once they are around five to seven years old and to treat about ten years as a serious replacement consideration regardless of tread depth. The DOT date code on the tire helps establish that timeline.

That age-based approach is especially important on a pre-war luxury car, where long intervals between drives can hide developing cracks, hardening, or internal deterioration. An older 1931 Cadillac may feel fine at neighborhood speeds and still have tires that no longer inspire confidence for a sustained outing. If the age is unclear, or if the tire has visible checking, deformation, or repeated pressure loss, replacement is usually the more responsible course before putting significant road miles on the car.

Tires on a 1931 Cadillac should be inspected before every drive and again before any longer outing. Check sidewalls for cracking, cuts, bulges, or signs of impact damage, and look at tread wear for uneven patterns that could point to alignment, suspension, or inflation issues. Pressure should be confirmed when the tires are cold, and the spare should be included in the inspection routine rather than treated as an afterthought on a touring car of this age.

A regular inspection habit matters because a 1931 Cadillac combines substantial vehicle weight with pre-war steering, braking, and suspension characteristics. Problems that seem minor in the garage can become much more noticeable once the car is moving at road speed. If the tires have been on the car for a long time, add a close look at valve stems and bead areas during inspection, and consider a more detailed evaluation before tours, club drives, or any event that will keep the car on the road for several hours.

A 1931 Cadillac V12 would have been fitted in the bias-ply era, and the V12 uses 700-19 or 750-18 depending on the car's wheel fitment. Those numeric sizes are exactly the kind of designation expected on a luxury American automobile from 1931, long before radial construction became standard. The correct starting point for authenticity is therefore the proper numeric bias-ply size for the specific V12 and its wheel diameter, rather than a later-style sizing system or modern radial conversion.

Because pre-war Cadillacs could vary by body style, market history, and decades of restoration work, owners aiming for factory-faithful detail should confirm their individual car against period references and marque-club knowledge before making a final choice. The most important authenticity markers are the right size, the correct bias-ply construction, and a sidewall style that suits the car's presentation. Getting those three elements right usually matters more than chasing a brand name unless you have model-specific historical evidence to support it.

Correct tire fitment matters a great deal when showing a 1931 Cadillac. Judges and knowledgeable enthusiasts will notice whether the size suits the model family, whether the construction matches the period, and whether the sidewall treatment looks appropriate for the car's restoration style. On a pre-war Cadillac, a mismatch in wheel diameter, an incorrect numeric size, or an obviously modern-looking tire can distract from an otherwise excellent restoration even if the car is mechanically sound.

For owners preparing a show car, the safest path is to confirm the exact size tied to the V8, V12, or V16 first, then choose the sidewall presentation that best supports the car's body style and the event's judging expectations. Some shows favor strict originality, while others are more tolerant of tasteful touring-oriented choices. Marque clubs, period photos, and event rulebooks are the best references for deciding whether a blackwall, wide whitewall, or double-whitewall treatment is most appropriate.

Where both are available for 1931 Cadillac sizes, Firestone Balloon and Lester Classic Bias Ply occupy the same vintage bias-ply world but differ in specific offerings and presentation. In 700-19, Firestone appears in blackwall and double-whitewall forms while Lester is offered as a blackwall. In 650-19, Firestone appears as blackwall and wide whitewall in Balloon form, while Lester appears as a wide whitewall. Both respect the correct pre-war sizing language, but the sidewall options vary by series and size.

That means the choice between them is less about changing the fundamental type of tire and more about refining the look of the finished car. A 1931 Cadillac restored for formal elegance may call for one sidewall presentation, while another restored with a more restrained visual character may point in a different direction. Once the correct size is established, comparing the available series by sidewall style and overall appearance is the best way to keep the tire aligned with the restoration's intended personality.

1931 Cadillac tires can be suitable for road use when they are in good condition, correctly sized, properly inflated, and used within the limits of their construction and the vehicle itself. Every listed fitment here is a bias-ply tire, and no explicit speed-rating letters are shown for these products. On a pre-war Cadillac, the car's own braking, steering, suspension, and overall mechanical condition are often just as important to real-world road safety as the tire choice, especially at normal secondary-road and moderate highway speeds.

The practical question is not whether a 1931 Cadillac can go on the road, but whether the entire car is prepared for the way you intend to use it. Fresh tires of the correct size are only one part of that picture. Before a longer highway run, make sure the tires are age-appropriate, free of visible defects, and matched to the correct wheel diameter, then evaluate the rest of the car with the same seriousness. A well-sorted pre-war Cadillac rewards conservative, thoughtful driving rather than modern-speed expectations.

Inflation pressure on 1931 Cadillac tires should follow the size and the exact tire you are using, not a single number carried across the whole model range. Listed examples include 650-19 at 1,430 pounds at 36 psi, 700-18 at 1,520 pounds at 36 psi, 700-19 up to 1,585 pounds at 36 psi, 750-18 at 1,930 pounds at 40 psi on Firestone passenger-car versions or 2,540 pounds at 65 psi on the Deka truck-style version, and 750-19 at 1,980 pounds at 40 psi.

That range is exactly why pressure should be tied to the specific tire and the car's intended use. Start with the original owner's-manual guidance for the vehicle if you have it, then compare that against the reproduction tire's rated pressure and load information for the exact size and series fitted to the car. Never assume that a pressure appropriate for one 1931 Cadillac size will be correct for another, and never transfer the Deka 750-18 figure to a passenger-car casing simply because the numeric size matches.

Before taking a 1931 Cadillac on a longer drive, inspect all five tires carefully for cracking, cuts, bulges, irregular wear, and any sign that the casing has aged beyond confidence. Verify cold inflation pressure, confirm that the spare is usable, and check that the wheels are the correct diameter for the tire size fitted. On a car of this age, the tire inspection should sit alongside a broader review of brakes, steering, wheel bearings, suspension points, fluids, and cooling system readiness.

That broader pre-drive routine matters because a pre-war Cadillac puts substantial demands on every mechanical system once the trip goes beyond a short local outing. A tire that merely looks acceptable in the garage may reveal balance, pressure-retention, or age-related issues after an hour on the road. If the car has been idle for a while, a short shakedown run near home before any tour is a smart way to evaluate how the tires and the rest of the chassis behave under real driving conditions.