The 1931 Cadillac V8 came from an era when Cadillac balanced prestige, scale, and engineering refinement with the formal presence expected of a premium American car. For owners restoring or maintaining one today, tire selection is closely tied to the car’s exact wheel setup, because this model uses either 650-19 or 700-18 bias-ply tires depending on sub-model. That means the first step is confirming whether the car is a Base model or a version with demountable wheels. From there, the real choice becomes period-style presentation, including blackwall, wide whitewall, or double-whitewall options, along with the tire series and rim-width requirements that suit the car’s current wheels.
Which Tire Size Is Right for The 1931 Cadillac V8
The 1931 Cadillac V8 uses two primary tire sizes, and the correct one depends on the sub-model and wheel arrangement. The Base model uses 650-19, while the version with demountable wheels uses 700-18, so identifying the exact sub-model and confirming wheel diameter come first. Once that is settled, the next decision is choosing the right bias-ply tire style, series, and sidewall treatment for the car’s appearance and intended road use.
A 650-19 tire uses the older numeric bias-ply sizing system, where 6.50 refers to the nominal section width in inches and 19 identifies the wheel diameter. On the 1931 Cadillac V8, this is a bias-ply fitment used on the Base sub-model, making it a restoration-oriented size for owners keeping the car in a traditional configuration. Available choices include Firestone, Lester, and Excelsior products, with blackwall and wide whitewall presentations across series such as Firestone Classic Bias Ply, Firestone Balloon, Lester Classic Bias Ply, and Comp H. This size is the right place to start when the car retains 19-inch wheels and the goal is authentic-looking vintage fitment.
A 700-18 tire follows the same vintage numeric bias-ply system, with 7.00 indicating nominal section width and 18 identifying the wheel diameter. For the 1931 Cadillac V8, this bias-ply size belongs to the version equipped with demountable wheels, so it should not be treated as interchangeable with the 19-inch setup. Product choices include Firestone, Lester, Excelsior, and STA offerings, with blackwall, wide whitewall, and double-whitewall appearances available across series such as Firestone Balloon, Firestone Classic Bias Ply, Lester Classic Bias Ply, Comp H, and Transport Highway. This size matters most when the car carries 18-inch wheels and needs a tire matched to that wheel configuration.
Sub-model fitment on the 1931 Cadillac V8 is not interchangeable, because the covered configurations use different tire sizes and different wheel diameters. Checking the exact sub-model matters before choosing a tire, especially when the car may have changed wheels at some point in its life.
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1931 Cadillac V8 Base
The 1931 Cadillac V8 Base uses the 650-19 bias-ply size on a 19-inch wheel setup. Tire selection here centers on choosing the right period-style look, such as blackwall or wide whitewall, while also confirming the wheel matches the original diameter now on the car.
The 1931 Cadillac V8 w/Demountable Wheels uses the 700-18 bias-ply size on an 18-inch wheel. That makes wheel confirmation especially important, and it also opens up appearance choices that include blackwall, wide whitewall, and double-whitewall options within the correct size.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Best 1931 Cadillac V8 Tires for Sale
Available 1931 Cadillac V8 tires span 650-19 and 700-18 bias-ply fitments from Firestone, Lester, Excelsior, and STA. Buyers can compare classic and balloon-style series, plus blackwall, wide whitewall, and double-whitewall presentations, along with wheel-width suitability on certain products.
Owners of a 1931 Cadillac V8 usually need to confirm the correct tire size first, then sort through wheel diameter, sub-model differences, sidewall style, and restoration-minded bias-ply choices. These FAQs focus on the fitment and practical checks that matter before the car goes back on the road.
Tire Size & Fitment
What tire size fits a 1931 Cadillac V8?
A 1931 Cadillac V8 uses either 650-19 or 700-18, and both are bias-ply tire sizes. The correct size depends on the sub-model: the Base uses 650-19, while the version with demountable wheels uses 700-18.
That difference makes wheel and sub-model confirmation the first step before choosing any tire. A 19-inch wheel requires the 650-19 fitment, and an 18-inch wheel requires the 700-18 fitment, so the sizes should not be treated as interchangeable simply because they belong to the same year and model family.
What size rim does a 1931 Cadillac V8 use?
A 1931 Cadillac V8 uses either a 19-inch or 18-inch rim, depending on configuration. The Base model uses the 650-19 tire on a 19-inch rim, while the Cadillac V8 with demountable wheels uses the 700-18 tire on an 18-inch rim.
Confirming actual wheel diameter on the car matters before ordering tires, especially on collector vehicles that may have had wheel changes over time. Rim width also deserves a look, since several available products in these sizes carry specific wheel-width ranges that can influence which tire series makes the most sense.
Do all 1931 Cadillac V8 sub-models use the same tire size?
No. The 1931 Cadillac V8 Base uses 650-19, while the 1931 Cadillac V8 w/Demountable Wheels uses 700-18. Both are bias-ply sizes, but they are tied to different wheel diameters and should be selected by exact sub-model and wheel setup.
That means tire choice starts with identifying the car correctly rather than choosing by appearance alone. If the Cadillac has been restored, modified, or fitted with replacement wheels at some point, checking the wheel itself is just as important as checking the model designation before moving on to sidewall style or tire series.
Choosing the Right Tire
What should I consider when choosing a 650-19 or 700-18 tire for a 1931 Cadillac V8?
Start with the correct size for the car’s sub-model and wheel diameter, because a 1931 Cadillac V8 may use either 650-19 or 700-18. From there, compare the available bias-ply tire series, sidewall styles, and any stated rim-width or load-capacity details that apply to the exact product.
A restoration-minded car may call for a different visual presentation than a driver that sees regular road miles. Blackwall, wide whitewall, and double-whitewall options change the car’s character noticeably, while wheel-width compatibility can narrow the best choices even within the correct size.
What sidewall styles are available for 1931 Cadillac V8 tires?
Sidewall choices for 1931 Cadillac V8 tires include blackwall and wide whitewall in both 650-19 and 700-18. The 700-18 size also includes a double-whitewall option, giving owners with the demountable-wheel setup another traditional appearance choice within the correct fitment.
Sidewall style is mostly an appearance decision once the proper size and wheel diameter are confirmed. A blackwall often suits a more restrained presentation, while wide whitewall and double-whitewall tires create a more formal pre-war look, so the right choice depends on how the Cadillac is being restored, shown, or driven.
What brands offer tires for the 1931 Cadillac V8?
Tires for the 1931 Cadillac V8 are available from Firestone, Lester, Excelsior, and STA, depending on size and series. Firestone and Lester appear in both primary sizes, Excelsior is also available in both, and STA appears in the 700-18 size through the Transport Highway series.
Brand is only one part of the decision. The more useful comparison is how each product lines up with the correct size, the visual style you want, and whether the wheel-width or load specification suits the Cadillac’s current setup. That approach keeps the choice practical instead of relying on name alone.
Restoration & Appearance
Which tire should I choose for a period-style 1931 Cadillac V8?
A period-style 1931 Cadillac V8 should begin with the correct primary size for the car’s actual wheel setup: 650-19 for the Base model or 700-18 for the version with demountable wheels. Both sizes are bias-ply, which preserves the traditional construction and visual character associated with an early-1930s luxury car.
After size and wheel diameter are confirmed, the appearance decision usually comes down to series and sidewall treatment. Blackwall, wide whitewall, and, on some 700-18 options, double-whitewall designs can all shape the final look. When exact historical presentation matters, marque-specific restoration references remain worth checking before making the final call.
How does tire construction affect the appearance of a restored 1931 Cadillac V8?
Tire construction has a strong visual effect on a restored 1931 Cadillac V8 because both primary fitments for this car are bias-ply sizes. Keeping a bias-ply tire maintains the tall, vintage presentation associated with the original era and supports the overall look expected on a formal pre-war Cadillac.
Appearance is not only about construction, though. Sidewall treatment plays a major role as well, with blackwall offering a more understated look and wide whitewall or double-whitewall options creating a more dressy period-style presentation. The best result comes from matching construction, sidewall style, and wheel diameter to the car’s intended restoration character.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1931 Cadillac V8?
Yes. Modifications can affect tire fitment on a 1931 Cadillac V8, especially if the car has replacement wheels, altered suspension height, brake conversions, or body and fender changes. Even when the correct tire size is chosen, wheel width and clearance can still influence which product works best on the car.
Collector cars often change over the decades, so it helps to inspect what is actually on the vehicle rather than assuming it still matches its original configuration. Turning clearance, fender clearance, and wheel diameter should all be checked before mounting new tires, particularly when the Cadillac has been restored in stages or updated over time.
What should I inspect before driving a 1931 Cadillac V8 on new tires?
Before driving a 1931 Cadillac V8 on new tires, inspect the wheels for the correct diameter and sound condition, then confirm the tires are properly seated and inflated. It also makes sense to look over steering and suspension components, since worn parts can affect how a large pre-war car tracks and responds on the road.
A short, careful test drive is a smart next step after installation. Watch for rubbing, unusual vibration, or steering pull, and recheck pressure after the first miles. On a seldom-driven collector vehicle, it is also wise to inspect the spare, valve stems, and overall wheel hardware before relying on the car for regular touring.
How should 650-19 and 700-18 tires on a collector 1931 Cadillac V8 be maintained?
Bias-ply 650-19 and 700-18 tires on a collector 1931 Cadillac V8 should be kept properly inflated, inspected regularly, and protected from long periods of heat, sunlight, and moisture. Tread depth matters, but age-related cracking, sidewall damage, flat spotting, and slow air loss are often just as important on a low-mileage antique car.
Regular visual checks help catch issues before they strand the car or damage a hard-to-replace wheel. Moving the Cadillac periodically during storage, keeping it on a clean dry surface, and checking condition before each outing can do as much for tire life as mileage-based maintenance on a vehicle that is driven only occasionally.
