1946 Buick Tire Fitment Guide

1946 Buick vehicles use two tire sizes, and the correct one depends on the model. The 1946 Buick 40 Special and 1946 Buick 50 Super use 650-16 bias-ply tires on 16-inch rims, while the 1946 Buick 70 Roadmaster uses 700-15 bias-ply tires on 15-inch rims. Listed 650-16 products call for 4.50- to 5.00-inch rim widths, and listed 700-15 products call for 5.00- to 5.50-inch rim widths.

That means year and make alone are not enough when ordering tires for a 1946 Buick. Start by confirming the model, then verify the wheel diameter on the car before choosing a tire. A Special or Super cannot simply use the Roadmaster’s size, and a Roadmaster cannot use the 16-inch fitment from the smaller Buick models without a wheel change.

On a 1946 Buick, 650-16 is a numeric bias-ply tire size. The 6.50 portion identifies the nominal section width, and the 16 identifies the wheel diameter in inches. For 1946 Buick applications, that size belongs to the 40 Special and 50 Super, and listed products in this size are built as bias-ply tires rather than modern radials.

Modern buyers sometimes read an older size code as if it were a current metric size, but the system is different. The key point is that 650-16 tells you both the vintage sizing family and the required 16-inch wheel. Once that is confirmed, the next choice is usually blackwall versus wide whitewall and which brand best suits the look of your Buick restoration.

On a 1946 Buick, 700-15 is also a numeric bias-ply tire size. The 7.00 portion indicates the nominal section width, and the 15 identifies the wheel diameter in inches. Within the 1946 Buick range, this size is used by the 70 Roadmaster, which sets it apart from the 16-inch fitment used on the Special and Super.

That difference matters because 700-15 is not just a slightly different-looking tire; it is built for a different wheel diameter. If you own a Roadmaster, verify that the car still has its proper 15-inch wheels before selecting from the available blackwall or wide whitewall bias-ply options. The size code is your first safeguard against choosing the wrong fitment.

1946 Buick models do not all use the same tire size. The 40 Special and 50 Super share 650-16 bias-ply tires, while the 70 Roadmaster uses 700-15 bias-ply tires. Buick’s lineup that year therefore splits into two fitment groups, and the break is tied to model identity rather than to optional constructions within the same size.

For a buyer, that means the first decision is not brand or sidewall style. It is confirming which Buick model you have and checking the wheel diameter already fitted to the car. Once that is established, you can compare the available brands and whitewall treatments within the proper size instead of trying to choose between two sizes that serve different models.

1946 Buick tires are available in both blackwall and wide whitewall styles. The 650-16 size used on Special and Super models appears in blackwall and wide whitewall versions, and the 700-15 size used on the Roadmaster is also offered in both blackwall and wide whitewall form. That gives owners flexibility whether they are aiming for a restrained driver look or a more formal postwar presentation.

For a 1946 Buick, sidewall choice has a strong visual effect because these cars carry full-bodied fenders and generous brightwork that work especially well with period-style whitewalls. Blackwalls can suit a simpler restoration theme, while wide whitewalls often match the upscale image many owners want. If the car will be judged, compare your choice with period photos and marque-club guidance for the most authentic presentation.

Several brands offer tires for 1946 Buick applications. In 650-16, the available brands are BFGoodrich, Coker Classic, Firestone, and Garfield. In 700-15, the available brands are Firestone, BFGoodrich, and STA. All of the listed options for these Buick sizes are bias-ply products, so the brand decision is mainly about appearance, series preference, and fitment within the correct size.

That brand spread is useful because it lets owners match the tone of the restoration to the car. A Roadmaster owner may want a traditional wide whitewall from Firestone or BFGoodrich, while a Special or Super owner has a broader 650-16 brand selection. The best way to narrow it down is to choose the correct Buick model first, then compare the sidewall style and brand presentation within that size.

Rim width requirements for 1946 Buick tires depend on the size. Listed 650-16 tires for the 1946 Buick 40 Special and 50 Super are matched to 4.50- to 5.00-inch rim widths, while listed 700-15 tires for the 1946 Buick 70 Roadmaster are matched to 5.00- to 5.50-inch rim widths. Those ranges align with the different wheel diameters used across the Buick lineup.

Before mounting new tires, measure the actual wheel or confirm its specification with a trusted wheel specialist if the car has been restored or modified in the past. Rim diameter and rim width both matter on a vintage Buick, especially if replacement wheels were installed decades ago. Staying within the listed width range helps preserve the intended shape and stance of the tire.

1946 Buick tire products in these sizes are listed without tube-type or tubeless markers in the size designation, so tube use should be confirmed against the specific tire and wheel combination you plan to run. Both 650-16 and 700-15 are vintage bias-ply sizes commonly associated with original-style steel wheels, and many collector-car owners verify tube needs at the same time they confirm wheel condition and valve-stem setup.

The practical step is to check the sidewall marking on the exact tire you choose and match that with the wheel’s design and condition before assembly. Original wheels, older restored wheels, and replacement rims can differ in how they are best set up. If your Buick will be driven regularly, it is worth having a shop familiar with vintage wheels review the full package before mounting.

A 1946 Buick should be stored in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, furnaces, and other ozone sources that age rubber. Because both Buick sizes here are bias-ply, long periods of static storage can encourage flat-spotting more readily than many radial designs. Keeping the car clean and the tires properly inflated also helps reduce stress on the sidewalls during lay-up.

If the Buick will sit for months, move it periodically so the same tread area is not carrying the load the entire time, or use stands in a way that does not create suspension issues. Owners who display the car more than they drive it should be especially mindful of indoor climate and sunlight exposure. Good storage habits preserve both appearance and ride quality on vintage bias-ply tires.

Tires on a 1946 Buick should be judged more by age and condition than by miles traveled. A collector tire should usually be inspected carefully once it reaches the five- to seven-year range, and many owners begin considering replacement as it approaches ten years old regardless of tread depth. The DOT date code on the tire sidewall is the starting point for tracking age.

That matters because many postwar Buicks are driven only occasionally, so a tire can look lightly used while still being well into its aging cycle. Sidewall checking, hardening rubber, repeated air loss, and changes in ride feel are all signs that calendar age is becoming more important than remaining tread. Regularly reviewing age keeps a low-mileage collector car from riding on old tires that look better than they truly are.

Tires on a 1946 Buick should be inspected before every drive and again before any extended outing. Look for sidewall cracking, cuts, bulges, uneven wear, foreign objects in the tread, and any sign that pressure is dropping between drives. A full walk-around is especially important on a collector Buick because long storage intervals can hide age-related deterioration.

A longer trip deserves a more deliberate check that includes the spare, valve stems, and the way the car feels during the first few miles. Vintage bias-ply tires can reveal problems through vibration, pull, or roughness once they start rolling after storage. Catching those signs early is one of the simplest ways to protect both the tires and the car.

The 1946 Buick 40 Special used 650-16 sizing, and bias-ply construction is the correct historical type for a Buick of this immediate postwar period. That same 650-16 fitment also applies to the 1946 Buick 50 Super, while the Roadmaster moves to a different size. Original-equipment branding could vary by market and surviving vehicle history, so the most reliable baseline is the correct size, construction type, and period-appropriate sidewall treatment.

For restoration work, getting those fundamentals right usually matters more than chasing a brand name first. A 650-16 bias-ply with the right visual style will read correctly on a Special in ways a wrong-size or wrong-construction tire will not. If your Buick is being restored for marque-level judging, compare your choice with factory literature, original photos, and Buick club guidance for model-specific details.

Correct tire fitment matters on a 1946 Buick because judges and knowledgeable enthusiasts notice size, construction type, and sidewall presentation quickly. A 40 Special or 50 Super wearing 700-15 tires, or a Roadmaster wearing 650-16 tires, would stand out immediately as incorrect. On a car judged for originality, modern-looking alternatives and sidewall treatments that do not suit the era can also draw attention away from an otherwise careful restoration.

The right approach is to match the tire to the model first, then choose the sidewall style that fits the standard you are building toward. Touring-oriented owners may accept some visual compromise, but concours-minded owners usually aim for the proper bias-ply format and era-consistent look. Event rules differ, so marque clubs and judging manuals are the best references when authenticity is the goal.

For the 1946 Buick 70 Roadmaster, both Firestone and BFGoodrich offer 700-15 bias-ply tires in wide whitewall form, and Firestone also appears in blackwall. The listed wide whitewall Firestone and BFGoodrich products share the same 1700-pound load rating at 32 psi and the same 5.00- to 5.50-inch rim-width range. Their published weights differ slightly, with Firestone at 29 pounds and BFGoodrich at 28 pounds in the whitewall versions shown here.

That makes the choice less about a dramatic spec gap and more about brand preference, sidewall appearance, and the particular visual character you want on the Roadmaster. Since both fit the same size and wheel family, many restorers choose the brand that best complements the theme of the car or matches other period details. If visual authenticity is critical, compare whitewall width and tread presentation carefully before deciding.

1946 Buick tires in 650-16 and 700-15 are available here as bias-ply designs, and bias-ply tires can be suitable for highway use when they are new, properly fitted, correctly inflated, and in good condition. These products are intended for vintage applications, but tire safety on a 1946 Buick also depends heavily on the car’s own mechanical state. Brakes, steering, wheel bearings, and suspension condition are often just as important as the tire itself on a postwar vehicle.

A well-sorted Buick driven within the limits of its design can travel comfortably on the road, but owners should expect bias-ply behavior rather than modern radial feel. That usually means more sensitivity to road crown, grooves, and longer static-storage flat spots. Before regular highway use, make sure the whole chassis is ready for the job rather than treating tires as the only variable.

Published load-and-pressure figures for 1946 Buick tire offerings include 1580 pounds at 32 psi for 650-16 products and 1700 pounds at 32 psi for 700-15 products where that specification appears. Those figures identify the tire’s rated load at a stated pressure, but they are not a blanket instruction to run every Buick at the same inflation setting. Factory recommendations for the car itself should still come from Buick literature or an authoritative marque source.

The best practice is to start with the vehicle maker’s recommended pressure for the correct model and size, then make sure the tire you select is being used within its rated limits. Do not borrow a pressure number from the Roadmaster’s 700-15 size and apply it to a Special or Super, or vice versa. Keeping each size with its own proper guidance preserves ride quality and helps avoid unnecessary wear.

Before a longer drive in a 1946 Buick, inspect all four tires and the spare for cracks, cuts, bulges, visible cord, uneven wear, and proper cold inflation pressure. Confirm that the wheel nuts are secure, the valve stems are in good shape, and the tires have not lost air during storage. On a collector car of this age, tire condition should be part of a broader check that also includes fluids, brakes, lights, charging system, and cooling system.

A short test drive before the actual trip can reveal vibrations, pulling, or flat-spotting that are easier to address at home than on the roadside. It is also wise to review the age of the tires and the condition of the spare before committing to distance. Long drives are much more enjoyable when the Buick and its tires have both been prepared with the same level of care.