1940 Pontiac Tire Fitment Guide

1940 Pontiac vehicles use two tire sizes: 600-16 and 650-16. The 600-16 size fits the 1940 Pontiac 25 and 26, while the 650-16 size fits the 1940 Pontiac 28 and 29. Both sizes mount on 16-inch rims, but they are not the same width, and the listed rim-width ranges differ where published: 600-16 appears with 4.00 to 4.50-inch rim recommendations, while 650-16 appears with 4.50 to 5.00-inch recommendations.

That means the first fitment question is your exact model, not just the year and make. A 1940 Pontiac owner restoring a 25 or 26 should begin with 600-16 options, while an owner of a 28 or 29 should stay with 650-16. Since all four models share the same wheel diameter, confusion usually comes from width rather than rim size, so checking the wheel against the intended tire remains an important final step.

On a 1940 Pontiac, 600-16 is a numeric bias-ply size. The "600" refers to the tire's nominal section width class, and the "16" identifies the wheel diameter in inches. Unlike a modern metric radial size, it does not spell out aspect ratio, and the construction here is bias-ply rather than radial.

That older sizing format is typical of prewar American cars, so it helps to read it as an era-correct designation rather than as a modern dimensional formula. On 1940 Pontiac, 600-16 belongs to the 25 and 26 models, which makes it the correct starting point for those cars whether you are choosing a blackwall for a simpler look or a whitewall for a more dressed-up restoration.

No, 1940 Pontiac models split across two sizes. The 25 and 26 use 600-16, while the 28 and 29 use 650-16. Every model listed here stays with a 16-inch rim diameter, but the larger-numbered models use a wider bias-ply tire than the smaller-numbered models.

That difference matters because many collectors know they have a 1940 Pontiac but may not immediately know which model series they own. If the car's body tag, title, or restoration paperwork identifies it as a 28 or 29, begin with 650-16 products; if it is a 25 or 26, begin with 600-16. Matching the size to the model is the best way to keep the car's stance and fitment in line with its original design.

1940 Pontiac tires are available in both blackwall and wide whitewall styles within the sizes used by the lineup. The 600-16 offerings include blackwall and wide whitewall examples, and the 650-16 offerings do as well. That gives owners of either size a choice between a more restrained service look and a more dressed, showroom-style presentation.

For a prewar American car like 1940 Pontiac, sidewall style can change the visual character of the car almost as much as wheel trim. A blackwall often suits a simpler, workmanlike appearance, while a wide whitewall is more in keeping with the upscale presentation many restorers want on a period passenger car. The right choice usually comes down to how your particular Pontiac is trimmed and how closely you want it to echo its original showroom personality.

Several brands offer tires for 1940 Pontiac vehicles. In 600-16, available brands include BFGoodrich, Coker Classic, Avon, and Firestone, along with additional lines in that size. In 650-16, available brands include BFGoodrich, Coker Classic, Firestone, and Garfield, again alongside additional offerings built around the same prewar bias-ply fitment.

Brand choice on a 1940 Pontiac usually comes down to the look you want and the exact series characteristics offered in your size, rather than chasing a single universal answer. Some owners prioritize a classic American brand identity, others focus on a specific tread or sidewall presentation, and some compare the available load or rim-width information more closely. Narrowing the correct size first makes those brand comparisons much more useful.

For 1940 Pontiac fitments shown here, BFGoodrich and Firestone both offer bias-ply choices in the year-correct numeric sizes, but the details differ by size and sidewall presentation. In 600-16, BFGoodrich appears as a 3.50-inch whitewall with a 1400-pound-at-32-psi rating and a 4.00 to 4.50-inch rim-width range, while Firestone appears as a 3.25-inch whitewall with the same 1400-pound-at-32-psi rating and the same rim-width range. In 650-16, BFGoodrich appears as a 3.75-inch whitewall with a 1580-pound-at-32-psi rating, while Firestone appears as a blackwall with the same stated load and pressure figure.

The practical difference is less about one being universally better and more about visual preference and the exact presentation you want on the car. A whitewall-width difference can noticeably change how formal or flashy a prewar Pontiac looks, and a blackwall versus whitewall choice changes the entire character of the finished restoration. Once your model confirms the size, compare sidewall treatment, load marking, and wheel compatibility rather than focusing on brand name alone.

1940 Pontiac rim-width guidance varies by tire size. In 600-16, listed products show recommended rim widths of 4.00 to 4.50 inches. In 650-16, listed products show recommended rim widths of 4.50 to 5.00 inches. Both sizes use 16-inch wheel diameters, but the wider 650-16 tires are intended for wider rims than the 600-16 tires.

That matters when a car has had wheel changes over the years or when original wheels are being mixed with reproduction tires. A 1940 Pontiac 25 or 26 owner should not assume a wheel suited to 650-16 is correct for 600-16, and the reverse is also true. Checking the wheel width before mounting helps preserve the tire's intended profile and avoids forcing an older-size bias-ply onto a wheel outside its stated range.

The listed 1940 Pontiac products do not consistently identify tube-type or tubeless status in the size markings shown here, so the safest approach is to verify the specific tire and wheel combination before installation. That is especially important on a 1940 Pontiac because these are prewar bias-ply applications on 16-inch wheels, and many collector-car wheel setups are used in ways that differ from modern passenger cars.

A tube decision should be made as part of the whole wheel-and-tire setup, not by assumption from size alone. If the wheel is an original-style rim or the tire's sidewall marking calls for a particular approach, follow that guidance exactly. Matching the tire, valve hardware, and wheel condition matters just as much as selecting the right numeric size, particularly on cars that spend long periods parked and then return to road use.

Original 1940 Pontiac wheels share the same 16-inch diameter across the sizes covered here, so diameter compatibility is consistent between 600-16 and 650-16. The catch is width: published fitment ranges show 600-16 working with 4.00 to 4.50-inch rims and 650-16 working with 4.50 to 5.00-inch rims on products where rim width is stated.

That means a 16-inch wheel is only part of the answer. A wheel suitable for a 1940 Pontiac 25 or 26 may not be the right width for a 28 or 29, even though both are 16-inch applications. If wheels have been swapped during the car's life, measure them before fitting tires, because confirming rim width is what determines whether the original wheel can sensibly support both the intended size and the correct tire profile.

A stored 1940 Pontiac should be kept in a cool, dry, dark environment away from direct sunlight, electric motors, battery chargers, furnaces, and other ozone sources that accelerate rubber aging. Because 1940 Pontiac uses bias-ply tires, long static storage can also encourage flat-spotting more readily than many later radial applications. Keeping the tires clean and properly inflated helps reduce stress on the casing while the car sits.

Owners who store a 1940 Pontiac for extended periods should move the car periodically or support it in a way that avoids leaving full weight on one contact patch for months at a time. A breathable car cover, dry floor surface, and regular pressure checks all help preserve both the tire and the wheel. If the car is stored with whitewalls fitted, gentle cleaning and keeping them out of UV exposure also helps maintain appearance.

On a collector car like a 1940 Pontiac, tire age matters more than mileage. A low-mile car can still be riding on rubber that has aged out, so a good rule is to begin close inspection once tires reach the five-to-seven-year range and to treat around ten years as a point where replacement deserves serious consideration. The manufacturing date code on the tire is the reference point for that timeline.

That approach is especially important for prewar bias-ply fitments because many antique and classic cars are driven occasionally and can appear fine at a glance while the rubber hardens with time. If a 1940 Pontiac has been in long-term storage or recently returned to service, check the actual age before relying on tread depth alone. A fresh-looking sidewall is helpful, but it is not a substitute for knowing how old the tire really is.

Tires on a 1940 Pontiac should be inspected before every drive and again before any longer trip or touring event. Look for sidewall cracking, irregular wear, cuts, bulges, and signs that the tire is no longer holding consistent pressure. Because these are vintage-style bias-ply applications, also pay close attention to valve condition and the general state of the wheel and bead area during routine checks.

Short local drives can hide problems that become much more serious once the car is warm and running at steady road speed. A few minutes spent checking pressures and walking around the car is a smart habit on any prewar Pontiac, particularly if it has sat for weeks or months. Consistent inspection also helps catch suspension or alignment issues early, since older cars often telegraph those problems through the tires first.

A 1940 Pontiac 25 would have been fitted in the bias-ply era, and the size used for that model here is 600-16. That aligns with what a buyer would expect from a prewar American passenger car, where bias-ply construction was standard practice. The exact brand originally delivered on an individual car could vary by plant, market, or replacement history, so size and construction are usually the first authenticity checkpoints.

For restoration work, the safest path is to treat 600-16 bias-ply as the core fitment and then choose the sidewall style that best matches the car's trim level and presentation goals. Owners building to a high judging standard should also compare surviving photos, literature, and marque-club guidance, since event standards often care about more than just the basic size. Getting the construction and sidewall appearance right goes a long way toward making a 1940 Pontiac look convincing.

Correct tire fitment matters a great deal when showing a 1940 Pontiac, especially in judged restoration settings. Judges and knowledgeable enthusiasts often notice whether the size matches the model series, whether the construction suits the era, and whether the sidewall style looks appropriate for the car's intended presentation. A 600-16 tire on a model meant to use 650-16, or the reverse, can change the car's stance enough to stand out immediately.

That does not mean every show applies the same rules, but it does mean tire choice should be intentional. A wide whitewall may suit one restoration theme, while a blackwall may better support another, and either can look wrong if the size itself is incorrect for the model. If the car will be judged, checking the standards used by Pontiac clubs or the specific event is the best way to confirm what those judges will expect.

For 1940 Pontiac fitments shown here, Coker Classic and Garfield differ in both application and presentation where they appear. Coker Classic is offered as a blackwall in 600-16 and also as a blackwall in 650-16, while Garfield appears in 650-16 as a Zig Zag Tread wide whitewall. In the 650-16 size, the Garfield listing includes a 1580-pound-at-32-psi rating and a 4.50 to 5.00-inch rim-width range.

That makes the choice less about simple interchangeability and more about the final restoration effect you want. A blackwall Coker Classic gives a cleaner, more understated period look, while the Garfield wide whitewall creates a more formal prewar presentation on the larger 1940 Pontiac models. If the car is being built with show-field authenticity in mind, tread appearance and whitewall treatment can matter almost as much as selecting the correct 650-16 size itself.

1940 Pontiac tires can be suitable for highway use when they are the correct size, in good condition, and used within their construction and speed-rating limits. The fitments covered here are bias-ply, and one 600-16 offering is marked H, which corresponds to a 130 mph speed ceiling. Other listed products emphasize vintage bias-ply construction and stated load capacity rather than prominent speed markings, so the specific tire's sidewall should always be read individually.

In real driving, the tire's rating is only part of the picture on a prewar car. A 1940 Pontiac's brakes, steering, suspension design, and overall mechanical condition usually matter more to safe cruising than the theoretical top speed of the tire. Owners planning regular highway use should make sure pressures are correct, the tires are fresh and evenly worn, and the car itself is roadworthy before assuming tire size alone answers the safety question.

Inflation pressure on a 1940 Pontiac should be set by combining the car's original factory guidance with the tire maker's rated information for the exact product you are using. In the sizes covered here, several 600-16 products list 1400 pounds at 32 psi, and several 650-16 products list 1580 pounds at 32 psi. Those are tire rating figures, not a blanket instruction to run every 1940 Pontiac tire the same way in service.

The practical approach is to begin with the vehicle's factory recommendation when available, then make sure it stays within the tire's stated limits and matches the car's actual use. A lightly driven collector Pontiac, a fully loaded touring car, and a freshly restored show car may all deserve closer attention to pressure maintenance even when using the same nominal size. Never transfer a pressure assumption from 600-16 to 650-16 or from one product line to another without checking.

Before a longer drive in a 1940 Pontiac, inspect every tire for cracking, cuts, bulges, unusual wear, and stable cold pressure, then check the spare as carefully as the four on the car. Look over the valve areas, wheel condition, and overall tread health, especially if the Pontiac has been sitting. On a prewar car, tire readiness is only one part of a broader roadworthiness check that should also include brakes, steering, fluids, and lighting.

Longer drives put more heat and sustained load into vintage tires than short local outings, so small issues become more important. It also helps to verify that the fitted size matches the model before departure, since 600-16 and 650-16 belong to different 1940 Pontiac series. A quick pre-trip walkaround and pressure check can prevent the kind of avoidable roadside trouble that takes the enjoyment out of driving a well-kept collector Pontiac.