The 1928 Buick 115 Standard comes from an era when Buick balanced upper-middle-market prestige with durable touring practicality, and tire choice remains a big part of preserving that character today. On this exact model, buyers will encounter two primary bias-ply fitments, 31X5.25 and 525-21, so the first step is confirming which wheel and tire convention the car is actually using. Available choices center on traditional bias-ply construction, with Firestone and Excelsior offerings in blackwall and wide whitewall form. For a restoration-minded Buick, the decision usually comes down to matching the car’s wheel setup, intended appearance, and how authentically period-styled the finished stance should look.
Which Tire Size Is Right for The 1928 Buick 115 Standard
The 1928 Buick 115 Standard uses two primary tire sizes, and they differ not only by size code but by tire format and rim diameter. Before choosing a tire, confirm whether the car is set up for 31X5.25 or 525-21, because wheel diameter is the key fitment checkpoint and both sizes appear on the 1928 Buick 115 Standard 6 Cyl. Once that is settled, the decision shifts to brand, sidewall style, and restoration-oriented presentation.
31X5.25 is an antique diameter-by-section size, meaning the first number refers to the tire’s approximate overall diameter and the second refers to its section width. This is a bias-ply fitment suited to the early tire conventions seen on late-1920s vehicles, so it should be approached as a specialty vintage application rather than a modern sizing system. That makes wheel confirmation especially important, since the code does not read like later numeric bias-ply sizes. This size is most relevant for owners trying to keep an early-period tire format on the car and should be checked carefully against the actual wheel setup before selection.
525-21 is a numeric bias-ply size in which the 5.25 designates nominal section width and the 21 identifies the rim diameter. On a 1928 Buick 115 Standard, it represents a traditional vintage fitment that keeps the car in a period-appropriate bias-ply construction. Available choices include Firestone and Excelsior tires, with blackwall and wide whitewall sidewall treatments and series such as Firestone Classic Bias Ply and Comp H. This size gives buyers room to tailor appearance and rim-width compatibility while staying within the correct vintage sizing family.
Fitment on the covered sub-model is straightforward in the sense that the same Buick 115 Standard 6 Cyl. is associated with both primary tire sizes. The important step is still confirming which wheel and tire format the car actually carries, since the two sizes use different rim diameters and represent different vintage sizing conventions.
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1928 Buick 115 Standard 6 Cyl.
The 1928 Buick 115 Standard 6 Cyl. is associated with both 31X5.25 and 525-21 bias-ply fitments, so tire selection begins with identifying the wheel setup already on the car. Once the rim diameter is confirmed, the choice becomes one of correct vintage sizing style, sidewall appearance, and the product characteristics that best suit the restoration.
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 1928 Buick 115 Standard Tires for Sale
Available 1928 Buick 115 Standard tire choices center on 525-21 bias-ply products from Firestone and Excelsior. Buyers can compare blackwall versus wide whitewall appearance, Firestone Classic Bias Ply versus Comp H series, and rim-width specifications that matter on an early wheel setup.
Owners of a 1928 Buick 115 Standard usually need help confirming the correct tire size, understanding the difference between 31X5.25 and 525-21, and choosing a bias-ply tire that suits the car’s wheels, appearance, and road use.
Tire Size & Fitment
What tire size fits a 1928 Buick 115 Standard?
The 1928 Buick 115 Standard is associated with two primary bias-ply tire sizes: 31X5.25 and 525-21. Both are vintage fitments, but they are not the same type of size designation. One uses an antique diameter-by-section format, while the other uses a numeric bias-ply format tied to a 21-inch rim.
That means the correct choice starts with the wheel and tire setup actually on the car, not just the model name. A Buick that currently carries 21-inch wheels points the search toward 525-21, while a car built around the 31X5.25 format needs that specific vintage convention checked carefully before replacing tires.
What size rim does a 1928 Buick 115 Standard use?
The 1928 Buick 115 Standard appears with two rim diameters tied to its primary tire fitments: 5.0 inches with 31X5.25 and 21.0 inches with 525-21. Those are very different wheel references, so rim diameter is one of the most important details to confirm before choosing a replacement tire.
A quick visual assumption can lead to the wrong size family on a vehicle from this era. Measure the wheel, verify the existing tire markings if they are legible, and compare the wheel to the intended tire’s rim requirements before ordering. Early cars are especially likely to have changed wheels or mixed-period components over time.
What does 525-21 mean on a 1928 Buick 115 Standard?
On a 1928 Buick 115 Standard, 525-21 is a numeric bias-ply size. The 5.25 refers to the tire’s nominal section width in inches, and the 21 identifies the rim diameter in inches. It is a traditional vintage sizing system commonly seen on cars from the late 1920s and early 1930s.
Understanding that format helps separate it from 31X5.25, which follows a different older convention. Once 525-21 is confirmed, buyers can focus on the details that matter within that size, such as blackwall versus wide whitewall appearance, brand choice, and whether the wheel width matches the tire’s intended rim range.
Choosing the Right Tire
What should I consider when choosing a 525-21 tire for a 1928 Buick 115 Standard?
Start by confirming that the car actually uses the 525-21 fitment and a 21-inch wheel. From there, the important differences are bias-ply construction, rim-width compatibility, sidewall appearance, and brand or series choice. For this Buick, 525-21 options include blackwall and wide whitewall styles from Firestone and a blackwall Excelsior Comp H.
A restoration-oriented car may call for a different visual presentation than a driver-focused preservation car. Compare the wheel width to the tire’s stated rim range, and consider how the tire’s look will affect the Buick’s stance. That keeps the decision grounded in both fitment and the appearance you want the finished car to carry.
What sidewall styles are available for 1928 Buick 115 Standard tires?
For the 1928 Buick 115 Standard’s 525-21 fitment, available sidewall styles include blackwall and wide whitewall. Those two treatments create very different visual impressions even when the basic tire size and bias-ply construction remain the same. Firestone offers both styles in this size, while Excelsior Comp H is available as a blackwall.
Sidewall choice has a strong effect on how formal, touring-oriented, or understated the car looks. A wide whitewall brings a more dressed appearance, while a blackwall keeps the presentation simpler and more mechanical. The best choice depends on the Buick’s restoration direction, wheel finish, and how period-styled you want the completed car to appear.
What brands offer tires for the 1928 Buick 115 Standard?
The 1928 Buick 115 Standard has 525-21 tire options from Firestone and Excelsior. Firestone appears in the Firestone Classic Bias Ply series, while Excelsior is represented by the Comp H series. Both are bias-ply choices, but they differ in sidewall treatments and rim-width specifications that may matter on an early vehicle.
Brand selection should follow correct size and wheel compatibility, not replace them. Once the car’s tire format is confirmed, compare the available series, sidewall look, and wheel-width requirements against the Buick’s intended use. That approach helps narrow the decision without assuming that every tire in the same nominal size suits every wheel setup equally.
Restoration & Appearance
Which tire should I choose for a period-style 1928 Buick 115 Standard?
A period-style 1928 Buick 115 Standard should begin with the tire size and construction that match the car’s actual wheel setup, which means staying within the 31X5.25 or 525-21 bias-ply fitment families as appropriate. For cars using 525-21, available options include Firestone Classic Bias Ply and Excelsior Comp H in traditional vintage presentations.
The right choice depends on whether the Buick is being finished as a formal restoration, a preserved driver, or a visually faithful tour car. Sidewall style can change the character noticeably, especially when choosing between blackwall and wide whitewall. When absolute originality matters, marque references and period photos are worth consulting before finalizing appearance details.
Does correct tire fitment matter for a 1928 Buick 115 Standard restoration?
Correct tire fitment matters a great deal on a 1928 Buick 115 Standard because the tire contributes heavily to stance, proportion, and overall period presentation. On a car from this era, using the wrong size family can change how the wheels fill the fenders and can make an otherwise careful restoration look visually out of step.
Fitment also affects practical details such as wheel compatibility and road clearance. The Buick’s two associated tire sizes use different sizing conventions, so accuracy starts with identifying the wheel and tire format already on the vehicle. That foundation makes later choices about sidewall style, brand, and series much easier to make with confidence.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1928 Buick 115 Standard?
Yes, modifications can affect tire fitment on a 1928 Buick 115 Standard, especially on a vehicle that may have seen wheel changes over many decades. Different wheels, altered suspension height, brake conversions, or body and fender work can all change which tire size is practical, even when the car still carries a historically familiar appearance.
That is why replacement tire selection should start with the Buick as it sits today. Measure wheel diameter and width, look for clearance at the fenders and steering components, and confirm that the chosen tire matches the car’s current hardware. Early collector cars often have long histories, and those histories can affect fitment more than the model name alone.
What should I inspect before driving a 1928 Buick 115 Standard on new tires?
Before driving a 1928 Buick 115 Standard on new tires, inspect the wheels, valve hardware, mounting surfaces, and overall tire clearance. Check that the tires are seated properly, inflated appropriately for the tire and vehicle setup, and free of visible issues such as sidewall damage, bulges, or irregular mounting that could affect early-car road manners.
A short, careful road test is a smart next step after installation. Pay attention to steering feel, fender and chassis clearance, and any sign of rubbing while turning or traveling over uneven pavement. On a collector Buick, it also helps to recheck pressure and wheel hardware after the first drive since newly mounted tires can settle slightly.
How should tires on a collector 1928 Buick 115 Standard be maintained?
Tires on a collector 1928 Buick 115 Standard should be maintained with regular pressure checks, visual inspections, and careful storage habits. Even a car that sees limited miles can develop age-related issues such as cracking, flat spotting, or air loss. Bias-ply tires also benefit from periodic inspection for tread wear patterns and sidewall condition.
Storage conditions matter almost as much as mileage on a low-use Buick. Keep the car away from prolonged sunlight, excess heat, standing moisture, and ozone sources such as electric motors or compressors. Before each driving season, inspect the tires closely and confirm that the wheel condition, mounting hardware, and overall fitment still support safe road use.
