1931 Gardner came from one of the more exclusive American independent automakers of the era, offering handsome, well-built cars aimed at buyers who wanted refinement outside the biggest mass-market names. By 1931, Gardner’s lineup still reflected late pre-war practice, with multiple body and chassis variations using true period bias-ply sizing rather than modern metric conventions. Across the three Gardner models offered that year, tire choice varies by model and by size family, with the 136 and 148 sharing one group of sizes while the 158 Series uses a larger set of its own. The first step with a 1931 Gardner is to confirm your exact model, then match the correct period tire size and wheel diameter before choosing sidewall style.
Which Tire Size Is Right for Your 1931 Gardner
Six tire sizes appear across 1931 Gardner vehicles, and they are not shared across the full model range. The real decision starts with confirming your model and wheel diameter first, since the 136 and 148 use 18- and 19-inch fitments while the 158 Series uses a different larger-size pairing on 18-inch wheels. Understanding those distinctions before choosing a product saves time and helps keep the tire matched to the right Gardner application.
29X5.50 is an antique diameter-by-section size, with 29 inches referring to overall tire diameter and 5.50 indicating nominal section width, and it is a bias-ply fitment specific to the 1931 Gardner 136 and 148 rather than the full Gardner line. No current products are listed here, so buyer choice within this size is centered on preserving the original size convention rather than comparing brands or sidewall treatments. This size suits owners researching an era-correct fitment path for a 136 or 148 and then confirming the exact wheel and replacement equivalent before moving forward.
Year(s): 1931|Fit(s): 136, 148|Construction: Bias Ply|Rim: 19 in
550-19 is a numeric bias-ply size in which 5.50 is the nominal section width and 19 is the wheel diameter, and it is used on the 1931 Gardner 136 and 148 rather than across every 1931 Gardner model. BFGoodrich offers this size in both Blackwall and Wide Whitewall versions, all as bias-ply tires on 19-inch fitments. This is the practical choice for 136 and 148 owners who want a clearly available replacement size with authentic pre-war construction and a choice between a plainer blackwall look or a more formal whitewall presentation.
28X5.50 is an antique diameter-by-section size, using overall tire diameter and nominal section width rather than the later numeric style, and it is a bias-ply fitment specific to the 1931 Gardner 136 and 148. No current products are listed in this exact size, so there is no brand or sidewall comparison to make within the size itself. Owners pursuing this fitment are usually focused on keeping the earlier sizing language and should confirm the actual wheel before selecting the nearest appropriate replacement path.
Year(s): 1931|Fit(s): 136, 148|Construction: Bias Ply|Rim: 18 in
550-18 is a numeric bias-ply size that denotes a nominal 5.50-inch section width on an 18-inch wheel, and it is specific to the 1931 Gardner 136 and 148 rather than universal across the make. Available brands include Excelsior, Firestone, and BFGoodrich, with Blackwall, Wide Whitewall, and Double-Whitewall sidewall styles offered in this size. This size gives 136 and 148 owners the broadest visible choice in period-style presentation, making it especially useful for restorations where the sidewall appearance matters as much as the basic fitment.
30X6.20 is an antique diameter-by-section size, with 30 inches identifying overall diameter and 6.20 indicating nominal section width, and it is a bias-ply fitment used only on the 1931 Gardner 158 Series. No current products are listed here, so there are no active brand, sidewall, or load comparisons within the exact size itself. This size is the more specialized path for the larger 158 Series and is best approached with close attention to the car’s actual wheels and original-style tire profile expectations.
Year(s): 1931|Fit(s): 158 Series|Construction: Bias Ply|Rim: 18 in
650-18 is a numeric bias-ply size, using a nominal 6.50-inch section width on an 18-inch wheel, and it is reserved for the 1931 Gardner 158 Series rather than the smaller Gardner models. Firestone offers this size in both Blackwall and Wide Whitewall versions, all in the Balloon series, with load figures reaching 1205 pounds at 36 psi on listed applications. This is the straightforward available fitment for a 158 Series owner who wants the larger pre-war balloon-tire look associated with a substantial early-1930s luxury car.
Three Gardner models are covered for 1931, and they do not all use the same tire sizes. The 136 and 148 share the same size families, while the 158 Series moves to a larger fitment, so identifying the exact model matters before choosing a tire. Select your model below to narrow the fitment history and see the products that relate to that Gardner specifically.
1931 Gardner 136
The 1931 Gardner 136 sat within Gardner’s upscale independent lineup, carrying the kind of conservative prestige and finely detailed coachwork buyers expected from a premium American car of the early Depression era. Its tires mount on either 18-inch or 19-inch wheels depending on the size path being followed, so the wheel itself needs to be confirmed before settling on a replacement direction.
The 1931 Gardner 148 shared Gardner’s formal, upper-market character, offering a larger and more prestigious presence than mainstream cars without leaving the traditional American luxury idiom of the period. Like the 136, it appears with both 18-inch and 19-inch wheel fitments across its listed tire sizes, making model identification only part of the process; the actual wheel diameter still matters.
The 1931 Gardner 158 Series represents the larger side of the Gardner range, with the more substantial tire sizing one would expect on a premium early-1930s automobile. Its listed tire options both mount on 18-inch wheels, but they are larger in overall section and character than the sizes used on the 136 and 148.
Eleven products are available across three listed tire sizes for 1931 Gardner vehicles. 550-19 includes 2 BFGoodrich bias-ply options in Blackwall and Wide Whitewall, 550-18 includes 7 bias-ply choices from Excelsior, Firestone, and BFGoodrich in Blackwall, Wide Whitewall, and Double-Whitewall styles, and 650-18 includes 2 Firestone bias-ply Balloon tires in Blackwall and Wide Whitewall.
These questions focus on how 1931 Gardner tire sizing changes between the 136, 148, and 158 Series, how antique and numeric bias-ply sizes relate to one another, and what to check for correct setup, show authenticity, and long-term collector use.
Size Basics & Fitment
What tire sizes fit 1931 Gardner vehicles?
1931 Gardner vehicles use six sizes across three models: 29X5.50, 550-19, 28X5.50, and 550-18 for the Gardner 136 and Gardner 148, plus 30X6.20 and 650-18 for the Gardner 158 Series. The 136 and 148 share both 18-inch and 19-inch fitments, while the 158 Series uses larger 18-inch sizes of its own. Where current product dimensions are listed, 550-19 fits 19-inch rims with a 2.50 to 3.00 inch width range, 550-18 fits 18-inch rims from 3.00 to 4.00 inches depending on the product, and 650-18 fits 18-inch rims from 3.25 to 3.50 inches.
That means year and make alone are not enough for a correct 1931 Gardner tire search. Start by identifying whether your car is a 136, 148, or 158 Series, then confirm whether it is on an 18-inch or 19-inch wheel before comparing antique-style and numeric replacements. On cars restored over many decades, wheel changes are possible, so checking the actual rim and the tire currently fitted is the most practical first move.
What does 29X5.50 mean on a 1931 Gardner tire?
On a 1931 Gardner tire, 29X5.50 is an antique diameter-by-section size. The first number, 29, refers to the tire’s approximate overall diameter in inches, while 5.50 refers to the nominal section width. That differs from later numeric sizing because the code is centered on the tire’s outside height and section rather than simply a width-and-rim format. For 1931 Gardner applications, this size belongs to the 136 and 148 models and represents a true pre-war bias-ply sizing convention.
Owners often encounter this style of marking on older restorations, literature, or surviving originals, even when a more commonly marketed numeric replacement may also exist. The important takeaway is not to treat 29X5.50 as a modern metric equivalent. If your Gardner still carries antique-format tires, compare the wheel diameter and the intended visual profile carefully before choosing a replacement path that preserves the car’s period stance.
Do all 1931 Gardner models use the same tire size?
No, 1931 Gardner models do not all use the same tire size. The Gardner 136 and Gardner 148 share four sizes—29X5.50, 550-19, 28X5.50, and 550-18—while the Gardner 158 Series uses the larger 30X6.20 and 650-18 sizes. Even within the 136 and 148 group, both 18-inch and 19-inch fitments appear, so there is more than one valid tire family depending on the wheel fitted to the car.
That model split matters because it changes more than just sidewall appearance. A 158 Series owner should be looking at a larger balloon-style fitment than a 136 or 148 owner, and a 136 or 148 owner still needs to verify whether the car is wearing an 18-inch or 19-inch wheel before moving any further. Matching by exact model first keeps the search focused and avoids crossing into a similar-looking but incorrect size family.
Buying the Right Tire
What sidewall styles are available for 1931 Gardner tires?
1931 Gardner tires are available in several sidewall treatments depending on size. In 550-19, BFGoodrich offers Blackwall and Wide Whitewall versions. In 550-18, the range is broader, with Blackwall, Wide Whitewall, and Double-Whitewall styles available from Excelsior, Firestone, and BFGoodrich. In 650-18 for the 158 Series, Firestone offers both Blackwall and Wide Whitewall versions.
For a 1931 Gardner, sidewall choice is usually about presentation and restoration intent rather than basic fitment. A blackwall often suits a more restrained or sporting look, while a whitewall gives the formal, upscale appearance many luxury American cars of the early 1930s wore in period. If the car will be judged, confirm whether the event expects a particular width or whitewall treatment for your body style and market before settling on the final appearance.
What brands make tires for 1931 Gardner vehicles?
Three brands currently appear in 1931 Gardner fitments: BFGoodrich, Firestone, and Excelsior. BFGoodrich is listed in 550-19 and 550-18, Firestone is listed in 550-18 and 650-18, and Excelsior appears in 550-18. All of the listed products are bias-ply tires, which is appropriate for a 1931 American luxury car and keeps the fitment aligned with the period construction Gardner owners generally seek.
Brand choice within a 1931 Gardner application usually comes down to the exact size you need and the visual style you want, since not every brand appears in every size. A 136 or 148 owner shopping 550-18 has the widest brand spread, while a 158 Series owner looking at 650-18 is in a narrower Firestone-only lane among the listed products. Once the model and wheel diameter are confirmed, brand selection becomes much easier to narrow.
What is the difference between Firestone and BFGoodrich in 550-18 for 1931 Gardner vehicles?
Within the 550-18 size for 1931 Gardner vehicles, Firestone and BFGoodrich differ in sidewall presentation, rim-width specification, load figure, and listed weight. Firestone appears in Blackwall and Double-Whitewall versions, each for a 3.25-inch rim and with a listed load capacity of 1125 pounds at 32 psi. BFGoodrich appears as a 3.00-inch whitewall tire for a 3-inch rim, with a listed load capacity of 1000 pounds at 32 psi and a slightly higher listed weight than the Firestone blackwall.
That comparison matters most for a 136 or 148 owner trying to match both the car’s wheel and the desired appearance. If your Gardner is on a 3-inch rim, the BFGoodrich entry lines up directly with that specification, while the Firestone options align with a 3.25-inch wheel. Instead of treating the choice as purely cosmetic, use the rim specification first and then decide whether the car should wear blackwall or whitewall styling.
Fitting & Setup
What rim width do 1931 Gardner tires require?
Rim-width requirements for 1931 Gardner tires vary by size and by product. In 550-19, the listed fitment range is 2.50 to 3.00 inches. In 550-18, listed products span from a 3-inch rim to a 4-inch rim depending on brand and series, including 3.00, 3.25, and 4-inch specifications. In 650-18, the listed range is 3.25 to 3.50 inches.
That spread is why wheel measurement matters before any purchase decision on a 1931 Gardner, especially on cars that may have been restored or re-wheeled decades ago. Two tires can share the same nominal size while targeting different rim widths, and that affects profile, stance, and the way the tire sits on the wheel. Measure the actual rim and match it to the specific tire’s approved width range instead of assuming any tire in the same size code will behave identically.
Do 1931 Gardner tires require inner tubes?
The listed 1931 Gardner tires are all pre-war bias-ply applications, but the individual product entries do not uniformly carry a tube-type or tubeless marking in the size line. On cars of this age, tube use is commonly tied as much to wheel design and condition as to the tire itself, especially where original-style rims are involved. For a 1931 Gardner, the practical assumption should be that tube decisions need to follow the exact tire and wheel combination rather than the size code alone.
Before fitting tires to a 1931 Gardner, confirm the wheel construction, valve-stem arrangement, and the specific tire’s sidewall marking. Original or original-style multi-piece and riveted wheels often call for more careful tube planning than later one-piece rims. If your car is headed for touring rather than occasional show use, it is worth reviewing the complete wheel and tube setup with a restoration specialist familiar with early-1930s American cars.
Can the original 1931 Gardner wheels be used with all tire sizes?
Original 1931 Gardner wheels cannot be treated as universal across all listed sizes because the year includes both 18-inch and 19-inch tire fitments, and the 158 Series uses a different larger-size family than the 136 and 148. A 550-19 tire requires a 19-inch rim, while 550-18 and 650-18 require 18-inch rims. The antique-format sizes in the same family also need to align with the correct wheel diameter for the model and fitment being followed.
A wheel can only serve multiple listed sizes when the rim diameter matches, and even then the rim width still has to suit the specific tire. On a 136 or 148, an 18-inch wheel may allow one 18-inch size path and a 19-inch wheel may allow the 19-inch path, but that does not make the two interchangeable on the same rim. Check diameter first, then compare the wheel’s width against the intended tire.
Maintenance, Storage & Longevity
How should I store a 1931 Gardner when the tires are fitted?
A 1931 Gardner 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 rubber. Bias-ply tires also benefit from keeping the car on clean surfaces and maintaining proper inflation during storage. If the car will sit for extended periods, periodic movement or the use of properly placed stands can help reduce long-term flat-spotting and sidewall stress.
Storage habits matter as much as mileage on a collector car like a 1931 Gardner because the tires may age out long before they wear out. A well-preserved bias-ply tire can still deteriorate if it spends years parked under low pressure or beside heat and ozone sources. If the car is part of a rotating collection, make tire inspection part of the routine whenever the Gardner is moved in or out of storage.
How long do tires on a 1931 Gardner typically last?
Tires on a 1931 Gardner are usually judged more by age than by tread wear. On a low-use collector car, a sensible rule is to begin evaluating tires closely once they are around five to seven years old and to treat ten years as a serious replacement consideration even if the tread still looks presentable. The DOT date code, overall casing condition, sidewall cracking, and how the car has been stored all matter more than mileage alone on a pre-war automobile.
That approach is especially important with bias-ply tires because a lightly driven car can create a false sense of security when the tread still looks fresh. A 1931 Gardner that only appears at shows or occasional drives can still be riding on rubber that has hardened with age. Checking the tire’s age and condition before each season is a better guide than waiting for visible wear bars or expecting a modern mileage interval.
How often should tires on a 1931 Gardner be inspected?
Tires on a 1931 Gardner should be inspected before every drive and again before any longer outing. Look for sidewall cracking, tread separation signs, cuts, embedded debris, bulges, and pressure loss, and make sure the valve stems are in sound condition. Because these are period-style bias-ply applications, any change in the way the car tracks or any new vibration should prompt a closer look at the tire and wheel assembly.
A pre-drive inspection is quick insurance on a car that may spend long stretches parked between uses. Collector cars often fail tires from age, storage damage, or underinflation rather than from ordinary wear. If your 1931 Gardner uses tubes as part of its final wheel-and-tire setup, include stem condition and any unexplained pressure loss in that routine, since tube and valve issues can show up before the outer casing looks obviously distressed.
Restoration & Authenticity
What tires were originally fitted to the 1931 Gardner 136?
A 1931 Gardner 136 would have been fitted in period with bias-ply tires, since that was standard construction for American passenger cars of the early 1930s. The listed size families for the 136 are 29X5.50, 550-19, 28X5.50, and 550-18, reflecting the pre-war overlap between antique-style diameter-by-section markings and numeric bias-ply sizing. No specific original-equipment brand should be assumed from that alone, because period fitment could vary by production run, dealer practice, and replacement history over the car’s life.
For restoration work, the right target is usually the correct size family, correct bias-ply construction, and the right visual treatment for the car’s intended presentation. If the car will be judged, compare surviving factory literature, original photos, and marque-club guidance before making the final call between blackwall and whitewall styling. That extra step is worthwhile because many pre-war cars accumulated replacement tires in later years that do not necessarily reflect factory delivery appearance.
Does correct tire fitment matter for showing a 1931 Gardner?
Correct tire fitment matters a great deal when showing a 1931 Gardner, especially in authenticity-focused judging. Size family, overall profile, bias-ply construction, and sidewall style all influence whether the car presents as period-correct. A modern-looking substitute, an incorrect wheel diameter, or a whitewall treatment that does not suit the car’s restoration theme can stand out immediately even to a casual observer, and more so to a knowledgeable judge.
On a car as uncommon as a Gardner, judges and enthusiasts often pay close attention to details that support the authenticity of the whole restoration. The tire should complement the era and class of the car rather than simply fill the wheel opening. If your 1931 Gardner is being prepared for concours-level display, use marque-club or event-specific standards to settle any close questions about exact sidewall treatment and acceptable replacement sizing.
What is the difference between Firestone Balloon and Firestone Classic Bias Ply for the 1931 Gardner?
For the 1931 Gardner, Firestone Balloon and Firestone Classic Bias Ply appear in different sizes and serve different fitment groups rather than acting as direct alternatives in one shared size. Firestone Classic Bias Ply appears in 550-18 for the Gardner 136 and 148, while Firestone Balloon appears in 650-18 for the Gardner 158 Series. The 650-18 Balloon tires are also listed with a 3.25 to 3.50 inch rim-width range and, in one listing, a load figure of 1205 pounds at 36 psi, reflecting the larger 158 Series application.
For restoration planning, that means the series distinction follows the vehicle’s size class as much as the visual style. A 136 or 148 owner should not treat the Balloon line as an upgrade path; it belongs to a different tire size family and a different Gardner model group. If your aim is authenticity, choose the series that corresponds to your model’s proper size rather than comparing the names as though they were interchangeable products.
Safety & Road Use
Are 1931 Gardner tires safe for highway driving?
1931 Gardner tires can be suitable for highway use when they are the correct size, in sound condition, and used within the limits of a pre-war bias-ply vehicle, but the listed products here do not show modern speed-rating letters such as S, T, or H. That means the practical limit is often set less by a published tire speed symbol and more by the overall condition of the tire, wheel, and the car itself. On a 1931 Gardner, braking, steering response, suspension wear, and chassis setup are usually the bigger real-world constraints at normal road speeds.
Highway readiness on a 1931 Gardner is really a systems question, not just a tire question. Freshly inspected tires on correct rims are only one part of the equation; the car also needs sound wheel bearings, steering components, and brakes that can match the intended trip. If your Gardner will be driven beyond local roads, treat the tire choice as part of a broader mechanical review rather than the sole indicator of roadworthiness.
What inflation pressure should I use for 1931 Gardner tires?
Inflation pressure on 1931 Gardner tires should follow the specific tire and the vehicle’s factory guidance rather than a one-pressure-fits-all rule. The listed load-and-pressure figures include 1040 pounds at 32 psi for 550-19, 1000 pounds at 32 psi for one 550-18 BFGoodrich listing, 1125 pounds at 32 psi for Firestone 550-18 listings, and 1205 pounds at 36 psi for one Firestone 650-18 listing. Those figures are tire ratings, not blanket instructions to apply the same pressure across every Gardner size or model.
Use the original owner’s literature or trusted marque guidance to establish the vehicle-side target, then confirm that the tire’s rated pressure and load capacity support that use. A larger 650-18 on a 158 Series should never automatically inherit the same pressure choice as a 550-18 on a 136 or 148. Pressure has a direct effect on ride, tread shape, and tire life, so it should be set deliberately after the model and exact tire are confirmed.
What should I check before taking a 1931 Gardner on a longer drive?
Before a longer drive in a 1931 Gardner, inspect each tire for cracks, cuts, bulges, unusual wear, loose debris, and proper inflation, and check that the spare is also usable. Look over the valve stems, wheel hardware, and the way the tire is seated on the rim, especially on a car that has seen infrequent use. Because Gardner models for 1931 span multiple size families, make sure the tires actually match side to side and axle to axle where they are supposed to.
That tire inspection should happen alongside a broader pre-drive check of brakes, steering, fluids, and the car’s cooling and charging systems. On a pre-war car, a problem that begins as a minor vibration or pressure loss can become far more serious once the car is out on a sustained run. Preparing the 1931 Gardner for distance is less about one dramatic issue and more about catching a dozen small ones before they have the chance to compound.
