1928 Marmon Tire Fitment Guide

1928 Marmon vehicles use six sizes across three model series: the 68 Series uses 29X5.25 and 5.25-19, the 75 Series uses 32X6.75 and 700-20, and the 78 Series uses 29X5.50 and 550-19. The 68 and 78 Series use 19-inch rim diameters, while the 75 Series uses a 20-inch rim diameter. Where current products are available, 700-20 fits 3.75-4.00 inch or 5.00-5.50 inch rim-width ranges depending on the tire, and 550-19 fits 2.50-3.00 inch rims.

That means year and make alone are not enough to choose a tire for a 1928 Marmon. Start by identifying the series, then confirm the wheel diameter already on the car, and only after that compare sidewall style and product details. If your Marmon has been restored over the years, check the stamping on the wheel and the size currently mounted before assuming the car still carries its original fitment family.

On a 1928 Marmon, 29X5.25 is an antique diameter-by-section marking. The first number, 29, is the tire's overall diameter in inches, while 5.25 is the nominal section width in inches. That differs from later numeric sizing, where the number before the dash usually represents width and the number after the dash represents wheel diameter. For 1928 Marmon applications, 29X5.25 belongs to the 68 Series and is a bias-ply size.

Collectors often encounter both antique and numeric markings on late-1920s cars because the industry was in transition. If your goal is historically faithful presentation, the sidewall marking style may matter as much as the actual dimensions. Compare the tire size called for by your series, the wheels on the car, and the restoration standard you are following before deciding whether to stay with the antique-marked size or use the corresponding later numeric convention.

For a 1928 Marmon, 700-20 is a numeric bias-ply size. The 7.00 refers to the nominal section width in inches, and the 20 refers to the wheel diameter in inches. On Marmon applications, that size is used on the 75 Series and mounts on a 20-inch wheel. Available versions come from Firestone and BFGoodrich, with blackwall, wide whitewall, and double-whitewall sidewall treatments offered in current reproductions.

Numeric sizing is usually easier for modern buyers to interpret because the wheel diameter is explicit in the code. Even so, 700-20 should not be treated as interchangeable with the 19-inch Marmon sizes used on other series. Once the wheel diameter is confirmed, the next choice is usually visual: blackwall for a more restrained look or whitewall styling for a more formal late-1920s luxury presentation.

No, 1928 Marmon models do not share one universal tire size. The 68 Series uses 29X5.25 and 5.25-19, the 75 Series uses 32X6.75 and 700-20, and the 78 Series uses 29X5.50 and 550-19. Two of those series use 19-inch rims, but they still do not use the same section-width family. The 75 Series stands apart with its 20-inch fitment.

That model-to-model variation matters because a Marmon owner can easily see a familiar 19-inch diameter and assume the tires interchange across the range. They do not necessarily do that. A correct choice starts with the series designation on the car, then moves to the exact size family for that series, and finally to the product style and rim-width match that suits the way the car is being restored or driven.

Current 1928 Marmon product coverage includes several sidewall looks, but only in the sizes with active offerings. The 700-20 size is available in blackwall, wide whitewall, and double-whitewall versions from Firestone and BFGoodrich, while 550-19 is offered in blackwall and wide whitewall versions from BFGoodrich. All of these are bias-ply tires, which keeps the construction style aligned with the late-1920s period even when the sidewall treatment changes.

Sidewall style affects the car's appearance as much as the tire size itself, especially on a luxury marque such as Marmon. A blackwall generally gives a more restrained look, while whitewall and double-whitewall treatments create a dressier, more formal presentation that many restorers associate with upscale pre-war cars. If the car will be judged, check event standards and period photos for your exact series before choosing purely by visual preference.

Two brands appear in current 1928 Marmon coverage: Firestone and BFGoodrich. Firestone offerings are present in 700-20, while BFGoodrich appears in both 700-20 and 550-19. All listed products for these Marmon sizes are bias-ply tires, which suits the pre-war character of the cars. Brand choice therefore comes down less to construction type and more to which exact size, sidewall style, and rim-width range you need.

That is especially useful if you are narrowing a 75 Series tire, because 700-20 gives you options from both brands and more than one visual treatment. A 78 Series owner shopping 550-19 has a narrower brand selection but still has a choice between blackwall and wide whitewall appearance. Treat brand as part of the final selection once the correct series and tire size are established.

On a 1928 Marmon 75 Series, Firestone and BFGoodrich both offer 700-20 bias-ply tires, but the details differ. Firestone versions carry 1930 pounds at 40 psi and fit 3.75-4.00 inch rims, while BFGoodrich versions carry either 1980 pounds at 42 psi or 1700 pounds at 36 psi and fit 5.00-5.50 inch rims. Firestone appears in wide whitewall and double-whitewall forms, while BFGoodrich appears in blackwall and wide whitewall versions.

Those differences matter because two 700-20 tires are not automatically the same match for the wheel already on the car. A Marmon owner should compare the actual rim width first, then choose the sidewall style that fits the intended appearance of the restoration. Weight differences also exist between products, but wheel compatibility and the visual character of the car usually deserve attention before smaller specification changes.

Where current 1928 Marmon products are available, rim-width requirements vary by size and by product. The 550-19 tires fit 2.50-3.00 inch rims. The 700-20 tires fit either 3.75-4.00 inch rims on Firestone versions or 5.00-5.50 inch rims on BFGoodrich versions. That means rim width is not just a year-and-make question; it can also differ within the same nominal tire size depending on the product selected.

Before choosing a tire, measure the wheel that is actually on the car rather than relying on assumptions from another Marmon or another reproduction tire. Older cars are often restored with substituted wheels, and even when the rim diameter is correct, the width may not be. Matching the tire to the wheel helps preserve proper section shape, bead seating, and the overall stance the car should carry.

The available 1928 Marmon tire listings shown here do not carry tube-type or tubeless markings in the size field, so the safe practical approach is to confirm the exact product's sidewall marking and the wheel's design before installation. For a 1928 pre-war application, many original-style wheels and tires are commonly used with tubes, especially in older bias-ply fitments, but the final setup should follow the tire and wheel combination you are actually using.

That matters because tube use is not just a tire question; it is also a wheel question. A restorer should inspect the wheel for condition, rivets, and sealing surfaces, then match the valve-stem and tube arrangement to the product selected. If your Marmon has had wheel changes during its life, verify the setup with a specialist familiar with pre-war rims before assuming the same practice applies across every series and wheel.

Original 1928 Marmon wheels can only be used with the tire sizes that match the correct wheel diameter for the series. The 68 and 78 Series use 19-inch fitments, while the 75 Series uses a 20-inch fitment. Even within those diameter groups, the listed sizes are tied to specific Marmon series rather than to the whole make. Rim width also has to be considered where current products are available.

That means an original wheel from one 1928 Marmon series should not be treated as automatically correct for another just because the cars share the same year. A wheel may accept the proper diameter tire yet still be a poor match in width or period appearance for the intended series. If the car has a mixed-parts history, inspect the wheel carefully and confirm the stamping, dimensions, and series-correct size family before fitting new tires.

A 1928 Marmon should be stored in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment that can age sidewalls. Because these Marmon fitments are bias-ply tires, they can develop flat-spotting more readily during long static storage than a modern radial. Clean floors, stable temperatures, and proper inflation help reduce distortion while the car sits.

Moving the car periodically can help, but many collectors also use tire cradles or place the car on stands for longer storage intervals to reduce sustained load on the casing. If you keep the car on its tires, roll it enough to change the contact patch occasionally. Storage planning matters on a heavy pre-war car because preserving tire shape and sidewall condition is often as important as preserving the paint and trim.

On a 1928 Marmon, tire life is usually judged more by age and condition than by mileage, because collector cars often see limited annual use. A sound rule is to inspect tires closely once they are around five to seven years old and to treat about ten years as a serious point for replacement consideration regardless of tread depth. The DOT date code on the tire sidewall helps establish age on modern reproduction products.

That approach is important because a low-mileage pre-war car can still be riding on rubber that has hardened, cracked, or weakened internally with time. A tire that looks cosmetically acceptable in the garage may no longer be one you want to trust on the road. If the age is nearing the outer end of the tire's service window, a fresh set is usually wiser than trying to stretch more seasons out of old rubber.

Tires on a 1928 Marmon should be inspected before every drive and again before any longer outing. Look for sidewall cracking, tread separation, cuts, bulges, irregular wear, and pressure loss, and make sure valve stems are in good condition. On a pre-war car, it also pays to inspect the spare, because it may be decades old even when the road tires have been changed more recently.

Frequent checks matter because collector cars often sit for extended periods and then return to service without the daily monitoring a modern driver gives an everyday car. Bias-ply tires can change shape during storage, and old wheel hardware can introduce leaks or vibration issues that only show up once you start using the car again. A few minutes of inspection before departure can prevent a much larger roadside problem.

A 1928 Marmon 68 Series would have been fitted with bias-ply tires, because that was standard construction for American passenger cars in the late 1920s. Within the 1928 Marmon range, the 68 Series uses 29X5.25 and 5.25-19 size designations on 19-inch wheels. The presence of both an early diameter-by-section marking and a later numeric marking reflects the period's evolving tire nomenclature rather than a shift to a modern construction type.

For a restoration, the real question is often which size marking and sidewall appearance best fit your car's build date, market presentation, and judging target. Original-equipment brand should not be assumed without period factory or dealer literature. If originality matters at a high level, compare your car with marque-club resources, period photos, and known surviving examples before choosing the exact sidewall wording and visual treatment.

Correct tire fitment matters on a 1928 Marmon because judges and knowledgeable enthusiasts often notice tire size, construction style, and sidewall treatment immediately. A series-correct bias-ply size on the proper wheel diameter supports the right stance and overall period character, while an incorrect size or an obviously mismatched sidewall treatment can stand out even from a distance. On pre-war luxury cars, whitewall style and sidewall proportions also influence the car's visual authenticity.

What counts as correct can vary by event, so concours standards and touring-class standards are not always identical. One show may emphasize exact period appearance, while another may allow more flexibility for practical use. Before finalizing a tire choice for a judged car, check the rules for the event you plan to enter and compare your selected size and sidewall style with marque-club guidance for 1928 Marmon presentation.

For 1928 Marmon restoration use, the difference is primarily visual rather than structural when you are comparing current products within the same listed size. In 700-20, blackwall, wide whitewall, and double-whitewall versions are available; in 550-19, blackwall and wide whitewall choices are available. All are bias-ply tires, so the restoration decision turns on appearance, era presentation, and how formal or restrained you want the finished car to look.

That choice can influence the character of the car as much as body color or trim details. A blackwall often suits a simpler, more understated presentation, while whitewall treatments give a richer, more upscale visual effect that many owners prefer on late-1920s luxury cars. If your Marmon is being restored for judged events, compare your choice with period imagery and club references rather than selecting solely by personal taste.

1928 Marmon tires in the listed sizes are bias-ply products, and no speed ratings are shown for the available 700-20 or 550-19 offerings here. That means highway use should be approached as a complete vehicle question, not just a tire question. On a late-1920s car, braking, steering, suspension condition, wheel integrity, and overall age-related mechanical limits are often more important than raw tire capability at ordinary road speeds.

A well-prepared Marmon can certainly be driven on today's roads, but it should be driven with the manners of a pre-war automobile in mind. Keep speeds sensible, allow extra stopping distance, and make sure the tires are fresh, correctly inflated, and matched to the wheels. If the car will see sustained touring, a thorough mechanical inspection is just as important as selecting the right tire size and sidewall style.

Inflation pressure for 1928 Marmon tires should follow the correct tire size and the product's own rated load-and-pressure information, not a generic number transferred from another Marmon series. Available 550-19 products list 1040 pounds at 32 psi. Available 700-20 products list either 1700 pounds at 36 psi, 1930 pounds at 40 psi, or 1980 pounds at 42 psi, depending on the specific tire. Those figures are tire ratings, not universal vehicle settings.

For the car itself, compare the tire's rated pressure information with the original owner's or service literature for your series and use judgment appropriate to the vehicle's load and driving conditions. Do not assume a pressure from a 700-20 tire belongs in a 550-19 tire, or vice versa. Keeping pressures consistent side to side is also important on a pre-war car because small differences can affect steering feel and tracking.

Before a longer drive in a 1928 Marmon, inspect each tire for cracking, cuts, bulges, uneven wear, lodged debris, and proper cold inflation. Check the spare as carefully as the four road tires, and make sure valve stems are sound and caps are in place. On an older collector car, also inspect the wheels for looseness, spoke or rim issues where applicable, and any signs that the tire has shifted or is not seating evenly.

That tire inspection should be part of a broader pre-drive routine that includes brakes, steering, cooling, fluids, and fuel-system checks. A Marmon from 1928 can cover meaningful distance when prepared properly, but age-related failures rarely announce themselves in advance. A careful walk-around and a few minutes under the hood can make the difference between an enjoyable tour and a trip interrupted by preventable tire or chassis trouble.