The 1926 Pontiac 6 Cyl. comes from Pontiac’s earliest years, when the brand was establishing itself as a value-minded companion to larger General Motors offerings and motorists still expected a very traditional ride and appearance. Tire selection on a car from this period is closely tied to wheel type, restoration goals, and how the car is actually used. The 1926 Pontiac 6 Cyl. uses bias-ply fitments in 29X4.75 and 4.75-20, so the first step is confirming which wheel and tire sizing system the car carries today. For many owners, the decision is as much about maintaining a proper prewar look as it is about fitment. Careful wheel measurement and a close inspection of the car’s current setup matter before any replacement is chosen.
Which Tire Size Is Right for The 1926 Pontiac 6 Cyl.
The 1926 Pontiac 6 Cyl. uses two primary tire sizes, and the difference is significant because they reflect different sizing conventions and different rim diameters. Before choosing a tire, confirm whether the car is set up for 29X4.75 or 4.75-20, since selecting between them starts with the actual wheel on the vehicle rather than appearance alone.
A 29X4.75 tire uses an older diameter-by-section format, where 29 refers to the tire’s approximate overall diameter and 4.75 refers to its nominal section width. This is a bias-ply fitment suited to an early motoring vehicle like the 1926 Pontiac 6 Cyl., where traditional construction and period-style proportions are central to the car’s look and stance. Because this format does not read like a later passenger-car tire size, it is important to match it carefully to the wheel already on the car. Owners usually evaluate this size when preserving an antique presentation and retaining the established wheel setup.
A 4.75-20 tire uses the vintage numeric bias-ply system, with 4.75 representing nominal section width in inches and 20 identifying the rim diameter. On a 1926 Pontiac 6 Cyl., this size keeps the car in a traditional bias-ply construction while using a more familiar period passenger-car sizing format than the antique diameter-by-section style. The key distinction is the 20-inch rim, which makes wheel confirmation essential before treating it as an alternative to any other size. This fitment is best evaluated by owners who are matching the car to its actual wheel dimensions and restoration direction.
Sub-model fitment is straightforward here because the covered Pontiac 6 Cyl. configuration falls under one Base listing, but tire choice still is not automatic. The important check is whether the car is running the wheel setup for 29X4.75 or the 20-inch setup for 4.75-20.
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1926 Pontiac 6 Cyl. Base
The 1926 Pontiac 6 Cyl. Base is associated with both 29X4.75 and 4.75-20 bias-ply sizes, so the tire decision depends on the actual wheels fitted to the car. That makes wheel measurement and a careful look at the existing tire markings especially important before choosing a replacement with the right period-style character.
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
Owners of a 1926 Pontiac 6 Cyl. usually need clarity on its two vintage tire sizes, the different rim requirements behind them, and what to inspect before putting an early Pontiac back on the road.
Tire Size & Fitment
What tire size fits a 1926 Pontiac 6 Cyl.?
The 1926 Pontiac 6 Cyl. uses two primary bias-ply tire sizes: 29X4.75 and 4.75-20. Those are both vintage fitments, but they are not just two ways of writing the same thing. They represent different sizing conventions, and they are tied to different wheel dimensions on the car.
The practical step is to confirm exactly what wheels are on the vehicle before choosing a replacement tire. A restored car, an older survivor, or a car that has been altered over the years may not match assumptions made from appearance alone. Reading the current tire size and measuring the wheel diameter will usually settle the question quickly.
What size rim does a 1926 Pontiac 6 Cyl. use?
Rim size depends on which tire size is on the car. A 29X4.75 fitment is associated with a 5.0-inch rim diameter, while a 4.75-20 fitment uses a 20-inch rim. That difference is large enough that rim confirmation needs to happen before any tire selection is made.
Wheel diameter should be verified directly on the vehicle rather than assumed from model year alone. Early cars often pass through decades of maintenance, restoration, and parts changes, and that can alter the tire setup. Checking the wheel itself, along with the size molded into the current tire, helps avoid ordering a period-style tire that belongs to a different rim.
Does the 1926 Pontiac 6 Cyl. Base use the same tire size?
The 1926 Pontiac 6 Cyl. Base is associated with both 29X4.75 and 4.75-20 bias-ply fitments. That means the Base designation alone does not narrow the car to one tire size. The deciding factor is the wheel and tire setup actually fitted to the vehicle.
For an owner, this means the next step is not choosing between brands or appearance details first. It means confirming whether the car carries the 5.0-inch rim arrangement used with 29X4.75 or the 20-inch rim arrangement used with 4.75-20. Once that is established, the correct vintage size can be selected with much more confidence.
Choosing the Right Tire
What should I consider when choosing a 29X4.75 or 4.75-20 tire for a 1926 Pontiac 6 Cyl.?
Start with the actual tire size and wheel diameter on the car, because the 1926 Pontiac 6 Cyl. uses both 29X4.75 and 4.75-20 bias-ply fitments. These are distinct vintage sizes, so the right choice begins with matching the wheel setup rather than selecting by appearance or by what seems close at a glance.
After size confirmation, think about how the car will be used and how authentic you want the finished presentation to look. A touring car driven occasionally may still need a strongly period-style tire, while a show-oriented restoration may place even more emphasis on correct visual proportion. Existing wheel condition, clearance, and overall vehicle setup deserve inspection before final selection.
How do I choose between the available 1926 Pontiac 6 Cyl. tire sizes?
Choosing between the available tire sizes is really a matter of identifying which setup your 1926 Pontiac 6 Cyl. already has. A 29X4.75 tire uses an antique diameter-by-section format, while 4.75-20 uses a numeric bias-ply format tied to a 20-inch rim. The size on the sidewall and the wheel measurement should agree before anything else is considered.
Once that is settled, the decision becomes simpler because both options keep the car in a traditional bias-ply construction. Owners should look closely at current wheel dimensions, tire-to-body clearance, and the overall stance of the car, especially if it has been restored long ago or assembled from mixed parts. Those checks matter more than trying to compare the two sizes abstractly.
What rim-fitment details should I compare when choosing 1926 Pontiac 6 Cyl. tires?
The most important rim-fitment detail is diameter. On a 1926 Pontiac 6 Cyl., 29X4.75 is associated with a 5.0-inch rim diameter, while 4.75-20 uses a 20-inch rim. Since these tire sizes do not share the same wheel size, the tire choice has to follow the wheel already on the car.
Beyond diameter, inspect the wheel for age, damage, trueness, and how the tire seats on it. Collector vehicles from this era may have seen repairs, parts substitutions, or long storage periods that affect serviceability. A correct-looking tire still needs to match a sound wheel, so it is worth checking the whole wheel-and-tire assembly before putting the car back into road use.
Restoration & Appearance
Which tire should I choose for a period-style 1926 Pontiac 6 Cyl.?
A period-style 1926 Pontiac 6 Cyl. should stay with the bias-ply construction and the exact primary tire size that matches the wheels on the car, either 29X4.75 or 4.75-20. Both sizes suit the vehicle’s era, but they are not interchangeable choices. The visual result depends heavily on using the size that belongs with the car’s actual wheel setup.
Owners focused on restoration should avoid treating appearance as separate from fitment. Tire diameter, section width, and wheel compatibility all influence stance and overall presentation, especially on an early car with tall, narrow tires. When exact historical authenticity matters beyond general period style, marque references and restoration records are useful final checks before committing to a tire choice.
Does correct tire fitment matter for a 1926 Pontiac 6 Cyl. restoration?
Correct tire fitment matters a great deal on a 1926 Pontiac 6 Cyl. because tires are such a visible part of an early car’s character. The wrong size can change the stance, wheel relationship, and overall visual balance even before any road-use concerns enter the picture. On a vehicle from this era, tires are part of the restoration story, not just a maintenance item.
Fitment also affects whether the car sits and operates as expected with its existing wheels. Since this Pontiac is associated with both 29X4.75 and 4.75-20, using the wheel-matched size is essential. A careful restoration approach means verifying what is on the car now, checking wheel condition, and selecting a bias-ply tire that preserves the vehicle’s traditional look and setup.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1926 Pontiac 6 Cyl.?
Yes, modifications can affect tire fitment on a 1926 Pontiac 6 Cyl., especially because this car already spans two distinct vintage tire sizes. If the Pontiac has replacement wheels, older restoration work, or parts carried over from earlier repairs, the tire size on the car may differ from what an owner expects from the model year alone.
That makes it smart to inspect the actual wheel diameter, current tire markings, and available clearance before choosing a replacement. Even on lightly used collector vehicles, changes in wheel design or body positioning can alter how a tire sits and steers. Verifying the present setup is the best way to avoid choosing a bias-ply size that does not suit the car as equipped.
What should I inspect before driving a 1926 Pontiac 6 Cyl. on new tires?
Before driving a 1926 Pontiac 6 Cyl. on new tires, inspect the wheels, valve hardware, and the overall condition of the mounting surfaces as carefully as the tires themselves. Early collector cars deserve a full walkaround that includes checking for sidewall damage, proper inflation, and any obvious mismatch between tire size and wheel.
A short test drive should follow only after confirming that the tires seat properly and clear the body and steering components throughout their range of motion. It also helps to recheck pressure and look for any signs of shifting or air loss after initial use. On an antique Pontiac, careful setup verification matters just as much as choosing the correct vintage size.
How should tires on a collector 1926 Pontiac 6 Cyl. be maintained?
Tires on a collector 1926 Pontiac 6 Cyl. should be inspected regularly for cracking, cuts, bulges, tread wear, and slow air loss, even if the car is driven only occasionally. Bias-ply tires on antique vehicles can age out from time and storage conditions as much as from mileage, so visual checks and pressure checks should be part of routine care.
Storage conditions also matter. Keeping the car away from prolonged sunlight, excess heat, standing moisture, and ozone sources can help preserve the tires between drives. It is also wise to inspect wheel condition at the same time, because an early Pontiac’s tire performance and serviceability depend on the whole wheel-and-tire assembly remaining sound, not just the rubber itself.
