Marquette 6 Cyl. Tires

Marquette 6 Cyl. was a short-lived late-1920s companion make from General Motors, built for buyers who wanted a six-cylinder car in the closing years before the Depression reshaped the market. That brief production window gives Marquette 6 Cyl. real collector interest today, especially among restorers who appreciate transitional pre-war engineering and styling. Tire selection is not completely straightforward because the same 1929 to 1930 model range appears with two different size conventions that can look similar at a glance while reflecting different ways of describing the tire. Before choosing, confirm exactly which size marking is called for on the car and verify the wheel and rim measurements on the vehicle itself.

Marquette 6 Cyl. Tire Size Guide

Marquette 6 Cyl. uses 2 distinct tire sizes across the 1929 to 1930 production span. One of those sizes uses the antique diameter-by-section format, where the leading number is the tire's outside diameter rather than the wheel diameter. That matters because the wheel size must be confirmed separately before selecting a tire.

28X5.251929-1930Antique diameter-by-section

28X5.25 is listed for Marquette 6 Cyl. models from 1929 through 1930. In this format, 28 indicates the tire's overall outside diameter in inches and 5.25 indicates the section width, while the wheel diameter is not contained in the size code itself. Choose 28X5.25 only when the car is specifically set up for that size, and confirm the actual rim diameter on the vehicle before final selection.

5.25-181929-1930Numeric bias-ply

5.25-18 is also listed for Marquette 6 Cyl. models from 1929 through 1930. The 5.25 identifies the nominal section width in inches and 18 is the rim diameter in inches, making this a numeric bias-ply size. Choose 5.25-18 when the car carries 18-inch wheels, and compare the existing tire marking and wheel diameter before moving ahead.

Marquette 6 Cyl. Tires by Year

The year listing below shows which tire sizes are associated with each 1929 and 1930 Marquette 6 Cyl. application. The leading number in 28X5.25 is the tire's outside diameter, not the wheel size, so the rim diameter needs to be checked separately. These year-by-year listings are best used alongside the tire marking on the car and original Marquette reference material when available.

Frequently Asked Questions

The FAQ below focuses on the two size conventions used on Marquette 6 Cyl., how to tell an antique diameter-marked tire from an 18-inch numeric size, and what to verify on a low-production pre-war car before choosing replacement tires.

Size Basics & Fitment

Marquette 6 Cyl. is listed with two tire sizes across 1929 and 1930: 28X5.25 and 5.25-18. The 5.25-18 size clearly uses an 18-inch rim, while 28X5.25 is an antique diameter-by-section marking where 28 is the tire's overall diameter and 5.25 is the section width, so the wheel diameter is not stated in the size code itself.

That means the correct choice depends on how the specific Marquette 6 Cyl. is equipped rather than the year alone. Start by reading the marking on the existing tire if it is still present, then confirm the actual wheel diameter and compare it with factory literature, restoration records, or marque specialists before settling on a replacement size.

On a Marquette 6 Cyl., 28X5.25 is an antique diameter-by-section size. The 28 refers to the tire's approximate outside diameter in inches, and 5.25 refers to the section width. Unlike a later numeric size such as 5.25-18, the wheel diameter is not shown in the 28X5.25 code.

That difference is important because a modern buyer can easily mistake the first number for the wheel diameter when it is actually the overall tire height. If your Marquette 6 Cyl. carries a size in this older format, measure the wheel or confirm the rim specification from trusted reference material before matching the car to a replacement tire.

Marquette 6 Cyl. is associated with at least one clearly identified 18-inch wheel application through the 5.25-18 size. The alternate 28X5.25 size does not reveal wheel diameter in the marking itself because it uses an older diameter-by-section convention. As a result, Marquette 6 Cyl. cannot be treated as a single wheel-diameter application from the size code alone.

The practical step is to inspect the wheel on the actual Marquette 6 Cyl. rather than assume the tire code tells the whole story. Reading the sidewall, measuring the wheel, and checking restoration paperwork together will usually separate a true 18-inch application from an older diameter-marked setup.

A Marquette 6 Cyl. should be approached as a pre-war application where tube-type tire practice is common, especially with older bias-ply and antique-size conventions such as 28X5.25 and early numeric formats like 5.25-18. Collector-car wheels from this period were often designed around tube-type service rather than modern tubeless use.

The right approach is to match the tire, tube, and wheel as a complete assembly instead of treating the tire alone as the fitment decision. If your Marquette 6 Cyl. still has original-style wheels, have the rims inspected for condition, sealing surfaces, and correct tube compatibility before the tires are mounted.

Buying the Right Tire

Because both 1929 and 1930 Marquette 6 Cyl. listings include 28X5.25 and 5.25-18, the year by itself does not settle the question. The surest identifiers are the size marking on the existing tire, the actual wheel diameter on the car, and any surviving factory or restoration records tied to that specific Marquette 6 Cyl.

Use the year listing as a starting point, then confirm the car's present configuration before replacing anything. That matters especially on older restorations, where wheels and tires may have been changed decades ago, leaving a Marquette 6 Cyl. with a valid size that differs from what another car of the same year carries.

Maintenance & Longevity

A stored Marquette 6 Cyl. benefits from a cool, dry, dark environment with clean floors and stable temperature. Tires on collector cars age from time, ozone, heat, and sustained loading as much as from mileage, so a low-use Marquette 6 Cyl. should not simply be parked and forgotten for long periods.

Keep the tires properly inflated, move the Marquette 6 Cyl. occasionally to change the footprint, and avoid contact with solvents, electric motors, or direct sunlight. For longer storage, many owners reduce stress by using tire cradles or carefully supporting the car so the full vehicle weight does not sit in one place for months at a time.

Tires on a Marquette 6 Cyl. should be visually inspected before every drive and given a more thorough inspection at least several times each season. Pre-war collector cars often see infrequent use, which makes cracking, flat spotting, bead issues, tube problems, and age-related deterioration easy to miss until the car is moved.

Look closely at sidewalls, tread, valve stems, and any signs of rubbing or uneven wear on the Marquette 6 Cyl. If the car is used for tours, parades, or regional events, it is wise to have the tires and wheels checked periodically by a shop familiar with vintage tire construction rather than relying only on casual garage inspection.

Tires on a Marquette 6 Cyl. should be replaced when age cracking, sidewall checking, persistent air loss, deformation, impact damage, or any structural concern appears, even if the tread still looks deep. Collector tires can age out long before they wear out, and that is especially true on low-mileage pre-war cars.

Age matters more than tread depth on a Marquette 6 Cyl. that spends much of its life at shows or in storage. If there is any doubt about the tire's serviceability, especially on an older restoration, have the assemblies inspected by a specialist before the car returns to regular road use.

Restoration & Authenticity

Marquette 6 Cyl. is associated here with two period-appropriate size expressions: 28X5.25 and 5.25-18, both appearing for 1929 and 1930. That tells you Marquette 6 Cyl. falls into a transitional pre-war sizing period where older diameter-by-section markings and later numeric rim-diameter markings can both enter the conversation.

For an authenticity-focused restoration, the best path is to match the specific Marquette 6 Cyl. to original literature, surviving tire placards, or strong provenance from the car itself. Restorers aiming for judging standards should treat broad year-range references as a guide and verify the exact configuration their own car carried.

Correct tire fitment can matter a great deal to the value, presentation, and judging of a Marquette 6 Cyl. Tire size, construction style, sidewall appearance, and overall stance all influence whether the car looks mechanically and historically right for its era.

A Marquette 6 Cyl. restored with the wrong overall diameter or an obviously mismatched size can sit incorrectly and lose authenticity points with knowledgeable judges. If the car is intended for concours or marque events, compare your tire choice with club guidance, period photographs, and original specifications before the restoration is finalized.

Sidewall style on a Marquette 6 Cyl. should match the period character of a late-1920s to 1930 pre-war automobile and the goals of the restoration. Cars from this era can look dramatically different depending on whether the owner is pursuing formal authenticity, a general touring presentation, or a specific coachwork appearance.

The right choice for a Marquette 6 Cyl. is usually the one that matches surviving photos, factory literature, and the trim level of the car rather than personal preference alone. If the restoration will be judged, consult marque references first so the sidewall treatment supports the overall historical presentation instead of distracting from it.

Safety & Road Use

A properly selected and properly mounted tire can make a Marquette 6 Cyl. suitable for careful public-road use, but safety depends on far more than tread depth alone. Wheel condition, tube condition where applicable, brake performance, steering integrity, suspension wear, and the car's long periods of storage all play a major role on a pre-war automobile.

Treat any Marquette 6 Cyl. as a vintage machine that needs a full systems check before being driven at modern traffic pace. Even with fresh tires, the car should be operated conservatively and within the limits of its chassis, brakes, and overall mechanical condition rather than according to what surrounding traffic happens to be doing.

Before driving a Marquette 6 Cyl., check tire pressure, visible sidewall condition, valve stems, wheel fasteners, steering response, brakes, and for any signs of rubbing or uneven stance. On a car from 1929 or 1930, a short garage inspection can catch many of the problems that develop quietly while the car sits between outings.

It is also wise to verify that all four tires on the Marquette 6 Cyl. match in size and general construction type. A careful test roll, followed by a brief low-speed drive, can reveal pull, vibration, brake imbalance, or wheel issues before the car is taken onto longer roads or into heavier traffic.

A Marquette 6 Cyl. should be driven at moderate, conservative speeds that respect both the period design of the car and the characteristics of vintage-style tires. Even when the size is correct, a pre-war chassis does not respond like a modern automobile in braking, steering, or emergency maneuvering.

The best practice is to let the Marquette 6 Cyl.'s mechanical condition, road surface, and tire construction set the pace rather than any theoretical top speed. Owners who keep speeds sensible and leave ample stopping distance generally get a far better and safer touring experience from cars of this age.