1930 Graham Tire Fitment Guide

1930 Graham vehicles use eight sizes across three models: 31X6.20 and 650-19 for the Custom; 28X5.50, 550-18, 30X6.00, and 6.00-18 for the Special; and 29X5.25, 5.25-19, 30X6.00, and 6.00-18 for the Standard. The Special and Standard share the 30X6.00 and 6.00-18 sizes, while the other six fitments are model-specific. Rim diameters span 17, 18, 19, and 20 inches across the range, so there is no single year-wide wheel fitment for 1930 Graham.

That matters because a buyer cannot safely identify a tire by year and make alone on a 1930 Graham. Start by confirming whether your car is a Custom, Special, or Standard, then verify the wheel diameter already on the car before selecting between antique diameter-by-section and numeric bias-ply sizes. If the car has been restored or modified over time, compare the actual wheel and tire markings against the model-specific fitments rather than assuming all 1930 Grahams used the same specification.

On a 1930 Graham, 31X6.20 is an antique diameter-by-section size. The first number, 31, refers to the tire's overall mounted diameter in inches, while 6.20 refers to the nominal section width in inches. In this early pre-war format, the rim diameter is not stated directly in the code the way it is on later numeric tires; this 1930 Graham Custom fitment mounts on a 20-inch wheel and uses bias-ply construction.

That older size format can be confusing because modern buyers are used to seeing the wheel diameter at the end of the size. If you are restoring a 1930 Graham Custom, 31X6.20 points you toward a tall, narrow, original-era style tire, and it should not be confused with a 19-inch numeric size such as 650-19. Matching the code correctly keeps the tire's profile and wheel relationship in line with how these early 1930s cars were intended to sit and drive.

On a 1930 Graham, 650-19 is a numeric bias-ply tire size. The 6.50 indicates the nominal section width in inches, and the 19 indicates the rim diameter in inches. That format differs from an antique size such as 31X6.20 because it emphasizes width and wheel diameter rather than overall tire diameter. On the 1930 Graham range, 650-19 is used on the Custom and mounts on a 19-inch wheel.

Knowing that difference helps when a Graham has already been restored, because a 19-inch numeric tire and a 20-inch antique size are not interchangeable even if both look period-correct at a glance. The numeric size is generally easier for modern buyers to recognize, and in 650-19 there are available blackwall and whitewall bias-ply choices. Before choosing one, check which wheel is on your Custom now, especially if the car has changed hands over many decades.

1930 Graham tire sidewall styles vary by size. In 650-19, available styles include blackwall and wide whitewall. In 550-18, available styles include blackwall, wide whitewall, and double-whitewall. Those options all remain within a pre-war bias-ply presentation, but they create noticeably different visual character depending on whether the car is being restored with a restrained driver look or a more formal luxury appearance.

For many 1930 Graham owners, sidewall style is the final decision after size and wheel diameter have already been confirmed. Blackwalls tend to suit a more utilitarian or understated presentation, while whitewall and double-whitewall treatments give the car a dressier period look that many restorers associate with upscale pre-war styling. If your goal is judged authenticity, compare your choice against period photos, club references, and the specific body style rather than assuming every 1930 Graham wore the same sidewall treatment.

Several brands appear in available 1930 Graham fitments. The 650-19 size is offered by Firestone and Lester, while 550-18 is represented by Excelsior, Firestone, and BFGoodrich. All of the products shown for those sizes are bias-ply tires, which aligns with what a 1930 American car would have used in period. Brand choice here is less about changing the underlying era of the car and more about size availability, sidewall styling, and the specific series offered.

That gives a Graham owner a few different ways to balance appearance and period character once the correct size is established. Firestone appears in both supported sizes, which can be useful if you are standardizing brand presentation across multiple restorations, while Lester, Excelsior, and BFGoodrich broaden the styling mix in their respective fitments. Choose the brand within the exact size your model uses first, then compare sidewall style and any listed load information before making the final call.

In 650-19 for 1930 Graham Custom applications, Firestone and Lester both offer bias-ply fitments, but they differ in styling and listed details. Firestone appears in blackwall form and also in a wide-whitewall Balloon version, with some products listing a 3.25 to 3.50 inch rim width range and one listing 1430 pounds at 36 psi. Lester appears here as a wide whitewall bias-ply tire. Product weights in this size range from 28 to 32 pounds among the listed options.

For a buyer, the practical difference is mostly in presentation and the exact specification attached to the individual product rather than a change in era or construction type. If your Custom is being restored with a formal whitewall look, both brands keep you in a proper pre-war visual territory, while Firestone also gives a plain blackwall path in the same size. Compare the wheel you have, the sidewall look you want, and the listed rated load information before settling on one version.

Rim width guidance is available for some 1930 Graham tire sizes. In 650-19, listed products include a 3.25 to 3.50 inch rim width range. In 550-18, listed products show fitments on 3-inch, 3.25-inch, and 4-inch rims depending on the tire. Those figures apply to the individual sizes and products where they are stated, not across the entire 1930 Graham range.

Use those numbers as a wheel-checking tool before choosing among the products available in a given size. A 650-19 tire should be matched to the narrower 19-inch rims called out for that fitment, while 550-18 products deserve a closer look because the listed rim widths vary from one version to another. If your wheels have been replaced, measured, or widened during an older restoration, confirm the actual rim width against the specific tire you plan to run.

Original 1930 Graham wheels cannot be treated as universal across all eight tire sizes because the year includes 17-inch, 18-inch, 19-inch, and 20-inch fitments. The Custom uses 19-inch and 20-inch sizes, the Special uses 17-inch and 18-inch sizes, and the Standard uses 18-inch and 19-inch sizes. Only the 30X6.00 and 6.00-18 fitments are shared, and they apply to the Special and Standard rather than to the full model range.

That means wheel compatibility starts with the exact car, not just the badge on the hood. If your Graham still has its original wheels, confirm their diameter before comparing tires. If the car has had wheel changes over the decades, rely on the wheel itself and the model identification instead of assuming another 1930 Graham's setup will transfer directly. Shared 18-inch fitments between the Special and Standard may simplify that comparison, but the rest of the lineup remains model-specific.

A stored 1930 Graham should be kept out of direct sunlight, away from electric motors or ozone-producing equipment, and in a dry, temperature-stable space. Bias-ply tires on pre-war cars are especially prone to flat-spotting if they sit in one position for long periods, and the sidewalls can age more quickly if exposed to heat, moisture, or petroleum contamination. Keeping the tires properly inflated during storage helps preserve their shape and reduces stress where the carcass meets the floor.

Move the car periodically if practical, or support it in a way that reduces long-term load without hanging the suspension unnaturally. A clean storage surface and tire covers can also help if the car sits near windows or fluctuating weather. With a 1930 Graham, storage habits matter because these cars often accumulate little mileage, so tire aging tends to be driven more by time and environment than by wear from regular road use.

Tires on a 1930 Graham are usually judged by age and condition more than by mileage. Collector-car tires should be inspected closely once they reach the five- to seven-year range, and many owners begin considering replacement as they approach about ten years from the date of manufacture even if tread remains deep. The DOT-style date code on the tire helps establish that timeline, and on a low-use pre-war car, sidewall aging often appears long before the tread is worn out.

That approach is important because a lightly driven 1930 Graham can still be riding on tires that look usable at first glance. Cracking, hardening, or changes in how the tire holds air can matter more than odometer miles. If the car is used only for tours, parades, or occasional events, make age checks part of your maintenance routine and do not assume low mileage automatically means the tire still belongs in active service.

Tires on a 1930 Graham should be inspected before every drive and again before any longer outing. Check for sidewall cracking, cuts, bulges, uneven tread wear, and signs that the car has been sitting on a low tire. Pressure retention matters just as much as visible condition on a pre-war car, especially when the vehicle spends long periods parked between uses.

A longer trip deserves a more thorough walk-around that includes the spare, valve stems, and the condition of the wheel itself. Older collector cars can mask tire issues because they are driven infrequently and at moderate speeds, so problems tend to build quietly over time rather than showing up through high annual mileage. Building a routine around every drive keeps small issues from becoming roadside failures on a 1930 Graham that may be far from home.

A 1930 Graham Custom would have been fitted with bias-ply tires in period, and the sizes associated here are 31X6.20 and 650-19. That reflects the transition-era reality of early 1930s American tire sizing, when both antique diameter-by-section and numeric conventions were seen across the market. The key authenticity point is construction and correct model-specific size rather than chasing a modern substitute format. No original-equipment brand should be assumed without verifying the car's market history and surviving references.

For restoration work, that means beginning with the car's exact wheel diameter and then choosing the size that aligns with how the Custom is set up today. If the vehicle is being judged, marque specialists and Graham club resources are the best place to confirm body-style, production-period, or market-specific details that go beyond the broad fitments used in 1930. Keeping the tire in a proper bias-ply format will do more for visual correctness than substituting a later-style construction or code system.

Correct tire fitment matters a great deal when showing a 1930 Graham because judges and knowledgeable enthusiasts look at size, construction, and sidewall character as part of the car's overall authenticity. A wrong wheel diameter, an incorrect size family, or a sidewall treatment that looks too modern for the restoration can distract from an otherwise accurate car. On a pre-war Graham, the difference between an antique diameter-by-section size and a numeric bias-ply size can also affect stance and visual proportion.

That does not mean every event applies the same standards, but it does mean tire choice is visible enough to influence how the car is received. If your Graham is being restored for formal judging, compare the selected tire against period photographs, marque-club guidance, and the expectations of the event where the car will appear. If the car is primarily for touring, some owners give a little more weight to appearance preference, but the fitment still needs to remain faithful to the model.

In 550-18 for 1930 Graham Special applications, Firestone and BFGoodrich are both bias-ply choices, but they differ in sidewall treatment and listed specifications. Firestone appears in blackwall and double-whitewall versions, with listed load capacity of 1125 pounds at 32 psi and a 3.25-inch rim width in the examples shown. BFGoodrich appears as a wide whitewall with a listed load capacity of 1000 pounds at 32 psi and a 3-inch rim width. Their listed weights also differ, with BFGoodrich heavier than the plain blackwall Firestone example.

For restoration decisions, that means the comparison is not just about brand name. The visual result changes with the sidewall style, and the wheel itself should be checked because the listed rim widths are not identical. If your 1930 Graham Special is being built toward a particular period look, choose the tire whose sidewall presentation matches the rest of the car, then confirm the wheel dimensions and rated load information align with how the car will actually be used.

1930 Graham tires in the sizes represented here are bias-ply products, and no speed ratings are shown for the available 650-19 and 550-18 examples. That means highway suitability should be treated conservatively and judged in the context of the whole car, not just the tire. A properly fitted new bias-ply tire in the correct size can be used on the road, but a 1930 Graham's brakes, steering, suspension, and overall pre-war design place their own practical limits on comfortable sustained speed.

For real-world use, think in terms of steady, moderate touring rather than modern interstate behavior. Make sure the tires are fresh, correctly inflated, and free from age-related cracking, then balance that with the condition of the chassis and driveline. Even when the tires themselves are in good order, the safe cruising pace for a 1930 Graham is usually determined more by the vehicle's era and mechanical condition than by trying to interpret it through modern tire expectations.

Inflation pressure on a 1930 Graham should follow the tire and vehicle combination you are actually using. Available examples list 650-19 at up to 1430 pounds at 36 psi, while 550-18 examples list up to 1125 pounds at 32 psi and 1000 pounds at 32 psi depending on the product. Those figures are rated load-and-pressure references for specific tires, not a blanket instruction to use the same pressure across every 1930 Graham size.

Use the original owner's literature or recognized Graham references to establish the vehicle's intended operating pressure, then compare that with the rating information supplied for the specific reproduction tire you choose. Do not transfer a 650-19 pressure assumption to a 550-18 or to one of the antique-format sizes, because the dimensions and product constructions differ. A careful pressure check before driving will do more for ride quality and tread life than relying on a one-size-fits-all rule.

Before a longer drive in a 1930 Graham, inspect all tires for cracks, cuts, bulges, irregular wear, and proper inflation, and make sure the spare is roadworthy as well. Look closely at the sidewalls because age damage on collector tires often shows there first. Wheel condition, valve stems, and how long the car has been sitting should all be part of the same inspection, since infrequent use can hide problems until the car is back at speed.

A longer outing in a pre-war car also deserves a broader mechanical check that includes brakes, steering play, wheel bearings, and fluid levels. Tires are only one piece of readiness, but they are the part in direct contact with the road and often the easiest place to catch trouble early. On a 1930 Graham, a few minutes spent checking tire condition and pressure before departure can make touring calmer, cleaner, and much less likely to be interrupted by avoidable issues.