The 1928 Davis 99 Series comes from the late brass-and-vintage era, when many American cars still carried tire sizing conventions that can look unfamiliar to modern buyers. For owners restoring or maintaining one of these uncommon late-1920s automobiles, tire selection is closely tied to preserving the car’s stance, wheel compatibility, and proper period character. The 1928 Davis 99 Series uses bias-ply fitments in two related sizes, 30X6.00 and 6.00-18, both centered around an 18-inch wheel application. That makes the real decision less about modern tire trends and more about understanding the size format, confirming the wheel setup, and choosing a tire that suits restoration goals and road use.
Which Tire Size Is Right for The 1928 Davis 99 Series
The 1928 Davis 99 Series uses two primary bias-ply tire sizes, and both appear on the 6 Cyl. sub-model. The first step is confirming which size format matches the car’s current wheel and tire setup, since one size is expressed as an overall-diameter style and the other as a numeric bias-ply size for an 18-inch rim. Once that is settled, the focus shifts to preserving the vehicle’s period look and verifying wheel compatibility before installation.
The 30X6.00 size uses an older diameter-by-section format, where the first number refers to the tire’s approximate overall diameter in inches and the second refers to its nominal section width. On the 1928 Davis 99 Series, this is a bias-ply fitment that reflects the sizing language commonly seen on vintage cars from the late 1920s. That makes it especially relevant for restoration-minded owners trying to preserve an authentic early automotive presentation. It is worth checking the wheel and the tire markings already on the car so this older format is matched correctly before selecting a replacement.
The 6.00-18 size is a numeric bias-ply format in which 6.00 represents the nominal section width in inches and 18 indicates the rim diameter. For a 1928 Davis 99 Series, this is a traditional vintage bias-ply fitment built around an 18-inch wheel. Buyers familiar with later alphanumeric or modern metric sizing should not confuse it with those systems, because the sizing convention is different even though the tire serves the same period-correct purpose. This size is a practical choice to evaluate when the car is already set up for 18-inch rims and the goal is to maintain a traditional vintage tire profile.
Sub-model fitment is straightforward here because the covered 6 Cyl. version uses the same two primary bias-ply tire sizes. Even so, checking the exact tire marking already on the vehicle still matters, since the two sizes use different vintage sizing formats and should not be treated as interchangeable without confirming the wheel setup.
1
1928 Davis 99 Series 6 Cyl.
The 1928 Davis 99 Series 6 Cyl. uses the same two primary bias-ply fitments found at the model level, so the key task is identifying which vintage size format is actually on the car. That means confirming the wheel and existing tire markings first, then choosing a replacement that supports the vehicle’s period-style appearance and intended road use.
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.
Frequently Asked Questions
These FAQs focus on the tire sizes used on the 1928 Davis 99 Series, how to interpret those early size formats, and what to check for wheel fitment, restoration appearance, and safe road use.
Tire Size & Fitment
What tire size fits a 1928 Davis 99 Series?
The 1928 Davis 99 Series uses two primary bias-ply tire sizes: 30X6.00 and 6.00-18. Both sizes are associated with the 1928 Davis 99 Series 6 Cyl., so the car can appear with either vintage size format depending on its wheel and tire setup.
The important next step is confirming which size is actually marked on the vehicle’s current tires and which wheel it is using. These are both vintage fitments, but they are written in different sizing systems, so replacement selection should begin with the existing wheel and tire combination rather than assuming the two markings mean the same thing.
What size rim does a 1928 Davis 99 Series use?
The 1928 Davis 99 Series is associated with an 18-inch rim diameter through its 6.00-18 bias-ply fitment. That rim diameter is the clearest wheel reference in the fitment details and is central to choosing the correct replacement tire size for a car still using that setup.
A vintage vehicle should always be checked in person before replacement tires are chosen, especially if it has been restored or modified over the years. Looking at the wheel itself and the sidewall marking on the current tire helps confirm that the car still carries the expected 18-inch arrangement and avoids ordering a tire based only on appearance.
Does the 1928 Davis 99 Series 6 Cyl. use the same tire size?
The 1928 Davis 99 Series 6 Cyl. uses the same two primary bias-ply sizes tied to this model: 30X6.00 and 6.00-18. That means sub-model identification is simple here, but the actual tire choice still depends on which vintage size format matches the car’s wheel and current setup.
That distinction matters because 30X6.00 and 6.00-18 are not just alternate spellings of the same modern-style tire size. Before replacing anything, inspect the sidewall markings already on the car and verify the wheel dimensions so the new tire follows the same vintage fitment path and preserves the proper look and clearance.
Choosing the Right Tire
What should I consider when choosing a 30X6.00 or 6.00-18 tire for a 1928 Davis 99 Series?
Start with the exact size the car is already set up to use, because the 1928 Davis 99 Series appears with both 30X6.00 and 6.00-18 bias-ply fitments. The main selection factor is not performance upgrading, but matching the vehicle’s established wheel arrangement and preserving the proper vintage tire profile.
A careful inspection of the current tires, wheels, and available clearance is the best next move. Cars from this era may have been restored at different times, so the correct purchase depends on the tire marking on the vehicle, the wheel diameter, and whether the goal is regular touring, display use, or a more restoration-oriented presentation.
How do I choose between the available 1928 Davis 99 Series tire sizes?
Choosing between the available sizes comes down to the wheel and tire format already on the car. The 30X6.00 marking uses an antique diameter-by-section system, while 6.00-18 uses a numeric bias-ply format tied to an 18-inch rim, so the correct path is the one that matches the vehicle’s actual setup.
That is especially important on a late-1920s automobile because size markings can look unfamiliar and restorations may not always follow the same approach. Checking the mounted tire, measuring the wheel if necessary, and keeping the car’s intended appearance in mind will help narrow the choice without guessing from a modern sizing perspective.
What rim-fitment details matter when choosing tires for a 1928 Davis 99 Series?
The most important rim-fitment detail is verifying the wheel diameter the car is actually using, especially when evaluating the 6.00-18 size. On a 1928 Davis 99 Series, wheel confirmation matters as much as the tire code itself because early tire markings can represent different sizing conventions than later collector-car owners may expect.
Beyond diameter, it is wise to inspect wheel condition, bead-seat integrity, and any signs that the car has been altered over time. A vintage tire can only perform as intended when it is matched to a sound wheel, so checking the rim carefully helps preserve both the period look and the practical usability of the car.
Restoration & Appearance
Which tire should I choose for a period-style 1928 Davis 99 Series?
A period-style 1928 Davis 99 Series should stay with the correct primary bias-ply size format already established on the car, whether that is 30X6.00 or 6.00-18. Both fitments suit the vehicle’s late-1920s character, so the right choice begins with matching the existing wheel and preserving the traditional tire profile.
Restoration buyers often care as much about stance and visual proportion as basic fitment. Looking at period photos, marque references, and the car’s own restoration history can help settle which size presentation makes the most sense, especially when the goal is an appearance that feels appropriate to the era rather than simply functional.
Does correct tire fitment matter for a 1928 Davis 99 Series restoration?
Correct tire fitment matters a great deal on a 1928 Davis 99 Series because the tire contributes heavily to the car’s overall stance, wheel presentation, and vintage character. Using the proper bias-ply size format helps the vehicle look and sit the way an owner expects from a late-1920s automobile.
That importance goes beyond appearance alone. A mismatched tire can create confusion at the wheel, interfere with the intended profile of the car, or complicate future restoration decisions. Confirming the size already used on the vehicle before replacement is one of the simplest ways to keep the restoration coherent and mechanically sensible.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1928 Davis 99 Series?
Yes, modifications can affect tire fitment on a 1928 Davis 99 Series, even when the tire size itself seems correct. Changes to wheels, ride height, suspension components, or bodywork can alter clearance and make a vintage bias-ply tire behave differently than it would on a car that remains close to its original setup.
That is why a visual and physical inspection matters before replacement tires are chosen. A car that has aftermarket wheels, altered fenders, or non-original suspension parts should be checked for wheel diameter, mounted-tire space, and steering clearance so the selected tire supports both safe use and the desired period presentation.
What should I inspect before driving a 1928 Davis 99 Series on new tires?
Before driving a 1928 Davis 99 Series on new tires, inspect wheel condition, lug hardware, valve stems, and overall tire seating on the rim. It is also smart to confirm that the tire sidewalls are free from damage and that the car rolls and steers without rubbing once the new bias-ply tires are mounted.
A short, cautious test drive is a sensible follow-up on a collector vehicle from this era. Pay attention to air retention, steering feel, brake behavior, and any contact with fenders or suspension parts, then recheck inflation and mounting after the first miles so the car is ready for regular vintage road use.
How should 30X6.00 or 6.00-18 tires on a collector 1928 Davis 99 Series be maintained?
Tires on a collector 1928 Davis 99 Series should be kept clean, properly inflated, and inspected regularly for cracking, cuts, bulges, and uneven wear. Because cars of this age are often driven infrequently, age and storage conditions can matter just as much as tread depth when judging whether a tire remains suitable for road use.
Storage habits also play a major role in preserving vintage bias-ply tires. Keeping the car away from prolonged sunlight, heat, moisture, and ozone sources can help slow deterioration, while periodic pressure checks and movement of the vehicle reduce the chance of overlooked problems developing during long periods of display or garage storage.
