DuPont E Tires

The 1927 DuPont E is associated with two tire sizes: 32X6.20 and 650-20. The 650-20 size is a numeric bias-ply size for a 20-inch rim, while 32X6.20 is an older diameter-by-section style where the leading 32 refers to overall tire diameter rather than wheel diameter.

That means a DuPont E owner should not choose by year alone and should not assume both sizes mean the same wheel setup. Start by identifying what is actually on the car now, then compare that with the wheel and tire markings, restoration records, and any surviving period information tied to the specific chassis.

On a DuPont E, 32X6.20 is an antique diameter-by-section size. The 32 refers to the tire's approximate outside diameter in inches, and 6.20 refers to nominal section width, so the first number is not the wheel diameter the way a modern buyer might expect.

That is the critical point when sorting out a DuPont E fitment, because the wheel diameter has to be confirmed separately from the tire code. If your car is wearing older-style removable rims or has been restored over many decades, inspect the wheel itself and compare proportions carefully before settling on an antique-format replacement.

A 1927 DuPont E has 2 tire sizes listed because two different period sizing conventions appear for that model year: 32X6.20 and 650-20. They are not simply modern and old spellings of the same thing, so the difference needs to be treated as a real fitment question rather than a catalog duplicate.

For a DuPont E owner, the practical takeaway is to verify the specific wheel and tire arrangement on the individual car. Cars from this era can reflect original factory practice, coachwork variation, later service replacements, or restoration choices, so the actual wheel and tire setup matters more than the model year by itself.

The available DuPont E products in 650-20 are bias-ply tires, and period bias-ply fitments of this type normally require tubes. That same tube-required approach is also consistent with the earlier 32X6.20 style sizing used on late-1920s cars.

When fitting tires to a DuPont E, plan the tire, tube, and rim condition as one system rather than treating the tire alone as the whole job. Clean wheel surfaces, sound flaps where needed, and proper tube sizing matter on collector cars that may sit for long periods and then return to limited road use.

To confirm the correct tire size for a 1927 DuPont E, begin with the wheel and any surviving tire markings on the car. The main choice is between 32X6.20, which is an antique diameter-by-section designation, and 650-20, which is a numeric bias-ply size built for a 20-inch rim.

Use several checkpoints rather than relying on one clue. Wheel diameter, rim profile, the stance of the car, restoration paperwork, and period service literature together will point you toward the proper fitment, and that is especially important on a low-production luxury car where later substitutions may have entered the picture.

Current DuPont E tire offerings in 650-20 include both wide whitewall and blackwall sidewall styles. The listed whitewall option is a 3.75-inch whitewall from Firestone, while several blackwall choices are also available in passenger-car and truck-style bias-ply patterns.

A DuPont E restoration owner should choose sidewall style according to the car's presentation and intended character. Whitewalls can suit a formal late-1920s luxury appearance, while blackwalls may be appropriate for a more understated period look or for owners prioritizing a utility-style tread in the available 20-inch bias-ply range.

DuPont E tire options in the listed 650-20 size come from Firestone, Denman, and Deka. Firestone appears in both passenger-style classic bias-ply offerings and truck-tread variants, while Denman and Deka appear in truck-oriented 20-inch bias-ply options.

That mix gives a DuPont E owner a choice between presentation-focused and utility-leaning period-style tires within the same nominal size. Compare the intended use of the car, the sidewall appearance you want, and the tread character before choosing, especially if the car will be shown, toured lightly, or moved mainly for display purposes.

The listed DuPont E tire series include Firestone Classic Bias Ply, Highway Classic Truck, Deka Classic Truck, and Firestone Classic Truck. The Firestone Classic Bias Ply offerings are passenger-car style tires, while the truck series options lean toward heavier-duty tread patterns and military or truck-type attributes in the same 20-inch size family.

For a DuPont E owner, the difference is less about modern performance categories and more about appearance, intended service, and period character. A concours-minded restoration may favor a passenger-style casing and sidewall treatment, while a car used for occasional moving, support duty, or a less formal presentation may lead an owner toward the truck-pattern alternatives.

A DuPont E should be stored on a clean, dry surface away from sunlight, ozone sources, and major temperature swings. Tire pressures should be kept at appropriate operating levels for the specific tire in use, and long static storage is easier on the tires if the vehicle's weight is reduced periodically by rolling it or supporting it properly.

Late-1920s collector cars often spend far more time parked than driven, which can flatten sections of bias-ply tires and stress old tubes, rims, and beads. Keep the car in a stable environment, avoid petroleum contamination on the rubber, and inspect the tire sidewalls and tread before and after each storage season.

Tires on a DuPont E should be inspected before every drive and more thoroughly at regular intervals during the season, even if the car covers very few miles. A proper inspection includes air pressure, sidewall cracking, tread separation signs, bead area condition, tube-related seepage, and any movement between tire and rim.

That routine matters because a collector car can look fine while age, storage history, and infrequent use quietly affect the tire structure. On a DuPont E, combine tire inspection with checks of wheel fasteners, brake condition, steering play, and suspension hardware so the car is evaluated as a complete prewar road system rather than as separate parts.

A DuPont E tire should be replaced when age, cracking, hardening, casing deformation, vibration, or any sign of structural weakness appears, even if the tread still looks deep. Tread depth alone is a poor guide on collector cars because these tires often age out long before they wear out.

That is especially important on a DuPont E that may still carry older restoration rubber or long-stored spare equipment. If an old tire's age or history is uncertain, have it examined by a specialist familiar with vintage bias-ply construction and tube-type fitments before trusting it for any meaningful road movement.

The DuPont E is associated here with two period size conventions, 32X6.20 and 650-20, which shows that more than one authentic-style fitment path can enter the conversation for a 1927 car. Current product offerings are concentrated in 650-20, with passenger-style classic bias-ply tires and truck-type alternatives available.

For a historically precise restoration, the right answer depends on the specific car rather than the model name alone. Surviving factory literature, marque references, restoration photos, and original wheel equipment should guide the final decision, especially on a luxury marque produced in small numbers and often restored over many decades.

Correct tire fitment can absolutely affect both presentation and judging on a DuPont E. Size, sidewall treatment, tread character, and overall stance all influence whether the car reads as properly restored for its late-1920s character, and judges often notice tires immediately because they are such a visible part of the car.

A DuPont E owner pursuing show accuracy should treat tires as a restoration decision rather than a final accessory. Matching the right size format, the proper wheel diameter, and an era-appropriate sidewall style will usually do more for authenticity than simply choosing the most visually attractive option available in a broadly similar size.

DuPont E tire options in 650-20 include both blackwall and wide whitewall styles, so either presentation can enter a restoration discussion depending on the car's intended appearance. The available whitewall is a 3.75-inch whitewall, while blackwalls appear in both passenger and truck-pattern offerings.

The correct choice for a DuPont E restoration should follow the car's trim level, period look, and the standard you are restoring toward. Owners building a formal, upscale presentation may lean toward a whitewall treatment, while blackwalls can suit a more restrained or utility-minded interpretation of a late-1920s open or closed car.

A properly fitted, sound-condition bias-ply tire can be appropriate for limited public-road use on a DuPont E, but safety depends on far more than the tire alone. The car's brakes, steering, wheel condition, tube integrity, alignment, and overall chassis health are just as important on a late-1920s automobile.

Treat a DuPont E as a collector car with vintage handling and braking, not as a modern highway machine. Even with fresh tires, it is wise to drive conservatively, avoid heavy traffic where possible, and build confidence gradually after any long storage period or recent restoration work.

Before driving a DuPont E, check tire pressure, sidewall condition, visible tread damage, valve stems, wheel attachment, and any signs that the tire has shifted on the rim. A full pre-drive routine should also include brakes, steering free play, wheel bearings, suspension condition, and fluid levels throughout the car.

That broader checklist matters because a DuPont E places vintage tire behavior into a vintage chassis system. A car that has sat for weeks or months can develop flat spotting, leaking tubes, sticky brakes, or steering issues, so the safest habit is a slow, deliberate inspection before each outing rather than a quick visual glance.

A DuPont E should be driven at moderate, conservative speeds that respect both bias-ply tire behavior and late-1920s chassis design. Even when the tire size is correct and the car is mechanically healthy, these tires are part of a vintage system that responds differently from modern radial-equipped cars in steering feel, stopping distance, and heat tolerance.

In practice, the right speed for a DuPont E is the one that leaves a wide margin for braking, road surface changes, and evasive movement. Keep pace with the car's age and condition rather than with surrounding traffic, and reserve higher sustained speeds for situations where the vehicle has been carefully sorted by an experienced vintage-car mechanic.