1948 Buick Tire Fitment Guide

1948 Buick vehicles use three different tire sizes, depending on model. The 1948 Buick 40 Special uses 650-16, the 1948 Buick 50 Super uses 760-15, and the 1948 Buick 70 Roadmaster uses 820-15. The Special size mounts on a 16-inch rim, while the Super and Roadmaster sizes mount on 15-inch rims. Listed rim-width ranges run 4.50 to 5.00 inches for 650-16, 5.50 to 6.00 inches for 760-15, and 6.00 to 6.50 inches for 820-15 on products that publish that information.

That means year and make alone are not enough for a 1948 Buick tire choice. A Special owner cannot assume that a Super or Roadmaster 15-inch size will interchange, and a Roadmaster owner should not size down to the Super tire without broader fitment research. Start by confirming the exact model on the title, trim tag, or body series, then compare the tire size on the car’s current wheels before choosing a replacement.

On a 1948 Buick, 650-16 is a traditional numeric bias-ply size. The 650 portion is the nominal section-width designation used in period sizing practice, and the 16 identifies a 16-inch wheel diameter. For 1948 Buick, that size applies to the 40 Special and appears in blackwall and wide whitewall versions from several brands.

A modern buyer should read 650-16 as an older-format size code rather than trying to compare it directly to a modern metric radial marking. The most useful takeaway is that the number after the dash tells you the wheel diameter, while the full code identifies the proper period bias-ply fitment for the Special. If your car already wears replacement wheels, confirm that they are still 16-inch before using 650-16 as your working size.

No, 1948 Buick models do not share one common tire size. The 40 Special uses 650-16, the 50 Super uses 760-15, and the 70 Roadmaster uses 820-15. Buick’s postwar lineup was tiered by size and market position, and the tire fitments reflect that separation rather than a one-size-fits-all approach.

That difference matters because the cars are not simply using alternate sidewall styles on the same basic size. The Special is on a different rim diameter altogether, and the Super and Roadmaster use different 15-inch numeric sizes. If you are shopping for a 1948 Buick only by year and make, identify the model first so you can move to the correct tire-size page or model page without sorting through sizes that belong to another Buick series.

1948 Buick tires are available in several period-appropriate sidewall treatments, depending on size. The 650-16 selection includes blackwall and wide whitewall options, the 760-15 selection includes narrow whitewall and wide whitewall options, and the 820-15 selection includes blackwall, narrow whitewall, and wide whitewall options. All of the listed choices are bias-ply tires, so the visual decision is mainly about how formal or understated you want the finished look to be.

For many postwar Buick restorations, whitewall width has a strong effect on the car’s overall character. A blackwall tends to look more restrained, while a wide whitewall leans into the upscale late-1940s Buick appearance buyers often expect on restored cars. Before settling on a sidewall style, compare it to period photos of your specific model and think about whether your goal is showroom-style presentation, a more conservative driver look, or something in between.

Several brands cover 1948 Buick fitments, but the mix changes by size. The 650-16 size is offered by BFGoodrich, Coker Classic, Firestone, and Garfield. The 760-15 size is offered by BFGoodrich, Coker Classic, and Universal Vintage Tire. The 820-15 size is offered by BFGoodrich, Firestone, and US Royal.

That brand spread gives a 1948 Buick owner room to choose not just the correct size, but also a tread and sidewall presentation that better matches the car’s intended finish. Some buyers prefer a familiar historical American name, while others focus first on the exact sidewall treatment available in the needed size. Once the model and size are confirmed, compare brands within that size rather than assuming the same brand lineup exists across the whole Buick range.

For 1948 Buick fitments where both brands appear, BFGoodrich and Firestone overlap in size coverage but not always in sidewall offerings or listed weights. In 650-16, both brands offer bias-ply tires with a 1580-pound maximum load at 32 psi on listed examples, while BFGoodrich is shown in a wide whitewall version at 24 pounds and Firestone in a blackwall version at 23 pounds. In 820-15, both brands list blackwall bias-ply tires with a 1920-pound maximum load at 32 psi, but BFGoodrich is listed at 28 pounds and Firestone at 33 pounds.

Those differences do not change the need to stay with the correct Buick model size, but they can affect the look and the way you compare product details within that size. If your priority is sidewall appearance, start there first, then compare the published load and wheel-range details on the specific product you are considering. A buyer restoring a show-oriented car may care most about the visible sidewall treatment, while a driver-minded owner may simply want the correct size from a preferred vintage brand.

Published rim-width ranges for 1948 Buick tires vary by size. The 650-16 tires list 4.50 to 5.00-inch rim widths on products that include that spec. The 760-15 tires list 5.50 to 6.00-inch rim widths on products that publish rim width. The 820-15 tires list 6.00 to 6.50-inch rim widths on listed examples.

Those ranges are important because even if the wheel diameter is correct, an out-of-range rim width can change section shape and overall stance. Use the tire size first to identify the proper Buick model fitment, then verify the actual wheel width on the car before committing to a tire. That is especially worthwhile on older cars that may have had wheels swapped over the decades, even when the outward appearance still looks period-correct.

The listed 1948 Buick products do not show tube-type or tubeless markings in the size field, so tube use should be confirmed on the specific tire and wheel combination you plan to run. All of the available sizes for 1948 Buick are bias-ply period-style tires, and many collector-car wheel setups from this era are commonly paired with tubes depending on wheel design, condition, and the exact tire construction.

The practical step is to inspect the wheel itself before finalizing the setup. Original steel wheels, restored rims, and later replacement wheels can have different requirements, and an old wheel condition issue may matter as much as the tire itself. If you are keeping original-style Buick wheels, confirm tube guidance on the exact product sidewall and with a knowledgeable installer before mounting, rather than assuming every 1948 Buick tire setup should be treated the same way.

A 1948 Buick should be stored in a cool, dry space away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment that can age sidewalls prematurely. Keep the tires properly inflated during storage, and if the car will sit for long periods, move it occasionally or place it on stands to reduce sustained flat-spotting. Bias-ply tires are especially prone to temporary flat spots after extended static parking.

That matters on a collector Buick because low annual mileage often hides tire aging better than it prevents it. A car that looks carefully kept can still develop sidewall weathering or storage-related shape changes if it sits in one place season after season. Clean, climate-stable storage and periodic movement do more for tire preservation than simply covering the car and leaving it untouched.

Tires on a 1948 Buick should be judged more by age and condition than by miles traveled. A good rule is to evaluate them closely once they are about five to seven years old and to treat around ten years as a serious replacement consideration, even if the tread still looks usable. The DOT date code, overall casing condition, and signs of cracking or hardening are more meaningful than odometer readings on a collector car.

That approach fits the way many vintage Buicks are actually used: short drives, show outings, and long storage intervals. A tire can age out long before it wears out, especially if the car spends time parked in heat or sun. If the tires came with the car and their age is uncertain, checking the date code is one of the simplest ways to decide whether you are maintaining a drivable setup or preserving a car on overdue rubber.

Tires on a 1948 Buick should be inspected before every drive and again before any longer outing or tour. Look for sidewall cracking, cuts, bulges, irregular tread wear, objects embedded in the tread, and any sign that the tire is losing pressure. On an older car, also pay close attention to valve stems and to the general condition of the spare, since a trunk spare may be just as old as the road tires.

Frequent inspection is especially important because collector vehicles can sit for weeks or months between uses. A problem that begins as a small crack or pressure loss can go unnoticed until the car is back on the road at speed. Building a short tire walk-around into your normal pre-drive routine is one of the easiest ways to make a vintage Buick more predictable and less stressful to use.

A 1948 Buick 40 Special would have originally been equipped with bias-ply tires, which was the standard construction for American passenger cars in that period. For the 1948 Buick lineup, the 40 Special uses 650-16, while the larger Super and Roadmaster use different sizes. Original-equipment brand selection could vary by market and supply, so the most important authenticity point is staying with the correct size and era-correct bias-ply construction for the model.

That gives restorers a clear starting place even before they sort out whitewall width or brand preference. If your goal is event judging or a highly faithful restoration, use period photos, factory literature, and Buick marque clubs to confirm the sidewall presentation that best suits your body style and market. Getting the construction and size right first will usually matter more than chasing a specific brand name without supporting evidence.

Correct tire fitment absolutely matters when showing a 1948 Buick, especially in classes that judge originality. Size, construction type, and sidewall style all influence whether the car looks consistent with its era and model position. A 40 Special wearing the larger Roadmaster size, or any 1948 Buick fitted with a visibly modern tire type outside period expectations, would stand out quickly to experienced judges and marque enthusiasts.

The right tire choice helps the whole car read correctly, from stance to wheel opening fill to the visual balance created by the sidewall. Whitewall treatment can also affect how formal or upscale the finished restoration appears. If you are building toward concours goals, check event-specific standards with Buick clubs or judging organizations, since some venues are stricter than others about construction type and sidewall appearance.

For the 1948 Buick 70 Roadmaster in 820-15, BFGoodrich and US Royal both offer bias-ply tires sized for the model’s 15-inch fitment, but they differ in sidewall presentation and listed weight. BFGoodrich appears in narrow whitewall and blackwall versions, with listed examples at 30 pounds and 28 pounds respectively, while US Royal appears in a 3.50-inch whitewall version at 29 pounds. Listed load capacity on these examples reaches 1920 pounds at 32 psi, and the published rim-width range is 6.00 to 6.50 inches.

That makes the comparison mostly a matter of appearance within the correct Roadmaster size rather than a change in fitment category. A blackwall gives a more restrained look, while the whitewall options shift the car toward a more formal late-1940s presentation. If you are trying to match a specific restoration style, compare the visible sidewall width first and then use the shared load and rim-range details as a secondary check.

The available 1948 Buick tires are bias-ply collector-style tires, and no speed ratings are shown in the listed size markings for these products. Highway use depends less on chasing modern-speed expectations and more on running the correct size for the model, maintaining proper inflation, and making sure the tire’s age and condition are suitable for service. On a late-1940s Buick, the car’s own brakes, steering, suspension, and general mechanical condition are often just as important to road confidence as the tires themselves.

A well-maintained 1948 Buick can certainly be driven on modern roads, but it should be driven with respect for its age and original design character. Smooth inputs, conservative speeds, and extra following distance are wise habits regardless of whether the car is a Special, Super, or Roadmaster. Before regular highway use, inspect the full chassis and confirm that the tires are fresh enough and matched correctly to the wheels now on the car.

Several 1948 Buick tire products list maximum load and pressure figures, but those are not the same thing as the carmaker’s recommended running pressure. The listed examples reach 1580 pounds at 32 psi for 650-16, 1710 pounds at 32 psi for 760-15, and 1920 pounds at 32 psi for 820-15. Those figures describe the tire’s published load rating at that pressure for that specific size and product, not a universal inflation target for every Buick model or use case.

Use the Buick owner’s manual or factory service information as the first reference for normal running pressure, then compare that guidance with the tire maker’s specifications for the exact product installed. Do not transfer a pressure figure from one 1948 Buick size to another just because both are bias-ply. Matching pressure to the correct model, tire size, vehicle loading, and actual driving use will produce the most predictable result.

Before a longer drive in a 1948 Buick, inspect all five tires for cracking, cuts, bulges, uneven wear, and proper inflation, and make sure the spare is usable rather than simply present. Look closely at valve stems, wheel condition, and any sign that a tire has been rubbing or losing pressure while the car was parked. Tires are only one part of the picture on a late-1940s car, so brakes, cooling system, steering, and lights also deserve attention before a touring run.

A longer drive is where a collector car’s little deferred-maintenance issues tend to reveal themselves. Catching a weak spare, a weathered valve stem, or a deteriorating sidewall before departure is far easier than solving it on the shoulder. If the car has been in storage, give it a short local test drive first so you can feel how the tires, steering response, and general road manners settle in before committing to distance.