1938 Nash Tire Fitment Guide

1938 Nash vehicles in this fitment group use two sizes: 6.25-16 and 700-16, and both apply to the 1938 Nash Ambassador. Each size fits a 16-inch wheel, so the rim diameter remains the same even though the overall section width changes between the two sizes. Rim width guidance appears within the available 700-16 offerings at 4.50 to 5.50 inches.

That means the first step is not choosing between different Nash models, since only the Ambassador appears here, but confirming which of the two sizes belongs on your specific car. If the car already has mounted tires, the sidewall marking is the quickest reference. If it is under restoration, compare the wheel and period fitment expectations before committing to one size or the other.

A 6.25-16 marking on a 1938 Nash is a traditional numeric bias-ply size. The 6.25 figure refers to the nominal section width in inches, while 16 is the wheel diameter in inches. It is not a modern metric radial code, so it should be read in the context of prewar bias-ply sizing rather than translated directly into a modern P-metric replacement.

That matters because a buyer looking at a 1938 Nash should not assume the code behaves like a modern width-and-aspect-ratio system. The tire's shape, sidewall profile, and driving character come from its bias-ply construction as much as from the numeric width itself. Matching the original-style size helps preserve steering feel, visual proportion, and wheel compatibility on a prewar car.

A 700-16 tire on a 1938 Nash is also a traditional numeric bias-ply size. In that older convention, 700 indicates the nominal section width and 16 identifies the wheel diameter in inches. Some 700-16 products also carry service markings such as load indexes or an L speed rating, but the base size itself remains a bias-ply numeric designation.

For a 1938 Nash owner, 700-16 should be treated as its own original-style fitment rather than a modern interchangeable shorthand. It keeps the car in the proper prewar sizing language and opens access to several period-appropriate tire choices. When comparing products in this size, focus on sidewall style, load marking, and wheel-width suitability instead of trying to compare it directly to a modern radial formula.

Within this year-and-make grouping, only the 1938 Nash Ambassador appears, and it uses two tire sizes rather than one universal fitment. Both 6.25-16 and 700-16 are associated with the Ambassador, so there is no split between different Nash model lines here. The question is which of those two sizes belongs on your specific car.

That is useful for buyers because it narrows the research quickly. You do not need to sort between multiple 1938 Nash model families first, but you do need to verify the actual size intended for your Ambassador. Checking the wheel, any surviving sidewall markings, and restoration references for your car's setup will usually answer that before you move on to brand or sidewall-style preference.

Both sizes are bias-ply and both fit 16-inch wheels, so the decision for a 1938 Nash is mainly about matching the car's correct original-style fitment rather than choosing between bias-ply and radial construction. The 6.25-16 is the narrower numeric size, while 700-16 is the larger numeric option and has the broader product selection in the currently available offerings.

A good way to decide is to start with what your Ambassador already uses or what your restoration references call for, then narrow by sidewall style. If you are preserving factory-style proportions, keep the car on its intended size rather than treating the two as casual substitutes. On a prewar car, the tire's visual scale contributes heavily to the stance and period look.

Current 1938 Nash tire offerings in 700-16 include both Blackwall and Wide Whitewall sidewall styles. Lester and Firestone options appear with Wide Whitewalls, while Avon and BFGoodrich options appear in Blackwall form. That gives the 1938 Nash owner a meaningful styling choice within the same basic bias-ply size.

Sidewall appearance affects the character of a prewar Nash almost as much as wheel finish or hubcap detail. Wide whitewalls usually suit a more formal or show-oriented presentation, while blackwalls tend to deliver a plainer, more utilitarian look. The right choice depends on how your Ambassador is being restored and the market-correct appearance you want the finished car to present.

The available 1938 Nash offerings in 700-16 come from Lester, Avon, BFGoodrich, and Firestone. All are bias-ply tires, but they differ in sidewall style and some service markings. BFGoodrich and Firestone options include stated load-and-pressure figures, while Avon includes a commercial-style 700-16C marking with an L speed rating.

That brand spread gives buyers several ways to approach the same basic fitment. Some owners will choose primarily by sidewall appearance, especially on a visible prewar restoration, while others will compare load markings and rim-width guidance to suit their intended road use. Once the size is confirmed, brand selection becomes more about presentation and product details than about changing the car's overall fitment category.

For 1938 Nash fitments, available rim-width guidance appears within the 700-16 products, where BFGoodrich and Firestone specify a 4.50- to 5.50-inch rim-width range. Both of those products are built for 16-inch wheels. That provides a useful benchmark when evaluating whether an original Ambassador wheel is suitable for a reproduction 700-16 tire.

Rim width matters because a bias-ply tire's shape and footprint can change when it is mounted on a wheel outside its intended range. Before fitting new tires, measure the wheel you plan to use rather than relying on assumption or appearance. If your car is being restored from mixed parts, that check is especially important, since a prewar 16-inch wheel can still vary in width.

The available 700-16 product markings shown here do not use a tube-type or tubeless designation, so tube fitment should be confirmed against the exact tire and wheel being used. On a 1938 Nash, that question also depends on the wheel design and condition, since original prewar wheels were commonly used with tube-type setups. A reproduction bias-ply tire does not automatically answer the tube question by size alone.

The practical move is to inspect the wheel first and then match the tire's sidewall marking and manufacturer guidance to that wheel. If the rim was designed for tubes, has riveted construction, or is being restored with original hardware, tube use is often part of a proper setup. Treat the tire size as only one piece of the decision, not the full answer.

Both 6.25-16 and 700-16 fit 16-inch wheels, so original 1938 Nash wheels can often accommodate either size at the rim-diameter level. That shared diameter is the key point of compatibility between the two sizes. The remaining question is whether the wheel's width suits the specific tire being considered.

For that reason, a diameter match alone should not end the fitment check. If you are moving to 700-16, compare your wheel against the published 4.50- to 5.50-inch range found on available products in that size. On a restored Ambassador, keeping the wheel and tire properly matched helps avoid unnecessary mounting issues and preserves the intended stance of the car.

A 1938 Nash should be stored away from direct sunlight, electric motors, welders, furnaces, and other ozone-producing sources that accelerate sidewall aging. Keep the car on a clean, dry surface and maintain proper inflation so the tires are not sitting partially deflated. Because 1938 Nash fitments here are bias-ply, they are more prone to temporary flat-spotting during long static periods than a modern radial would be.

Periodic movement helps distribute the load across a different part of the tread and reduces the chance of a set developing a persistent shape from sitting. For longer storage, some owners rotate the car slightly every few weeks or support it carefully to reduce constant load on the tires. Either approach works better when combined with a cool, dark storage environment.

On a 1938 Nash, tire age usually matters more than mileage because collector cars are often driven infrequently. A practical rule is to begin evaluating tires closely once they reach about five to seven years of age and to treat around ten years as a serious replacement point, even if tread depth still looks usable. The DOT date code on the tire sidewall is the reference for age on modern reproduction tires.

A prewar car can hide tire aging because it may see only short drives, local shows, or seasonal use. That makes visual condition only part of the story. If your 1938 Nash still wears older tires with little wear, inspect them for hardening, cracking, and changes in ride quality, and let age carry more weight than the odometer when planning replacement.

Tires on a 1938 Nash should be checked before every drive and again before any longer outing. Look for sidewall cracking, tread separation signs, bulges, embedded objects, and pressure loss, and inspect the spare as well since it may become part of the trip plan on a collector car. A short local run can mask problems that become more serious once the tire is hot from sustained use.

Routine inspection is especially important on an older car because steering, braking, and suspension systems do not have the reserve margins of a modern vehicle. Make the walk-around part of the starting ritual rather than an occasional task. If your wheel-and-tire setup uses tubes, include the valve stems in that check so aging rubber there does not become the weak point.

A 1938 Nash Ambassador would have been a bias-ply car when new, and the fitment range here reflects that period-correct construction with 6.25-16 and 700-16 sizes. Those are both traditional prewar numeric bias-ply sizes mounted on 16-inch wheels. Original equipment branding could vary by market, dealer, and production circumstances, so the important first step is confirming the correct size and sidewall treatment for your particular car.

For most restorations, getting the construction type right is the foundation of authenticity. Once that is settled, sidewall style becomes the next visible decision, especially on a larger prewar sedan where the tires contribute strongly to the finished look. If you are preparing for judged events, compare your car against period photos and consult Nash marque specialists for trim- and market-specific expectations.

Correct tire fitment matters on a 1938 Nash because prewar judging often looks closely at size, construction, and sidewall appearance. A bias-ply tire in the proper numeric size aligns with the period, while an obviously modern construction or an out-of-era sidewall treatment can change the car's profile and visual authenticity. On a large prewar car, those differences are easy to spot.

That does not mean every event uses the same standard, but it does mean tire choice should be part of the restoration plan rather than an afterthought. Owners aiming at serious judging should verify what the relevant club or event expects before selecting between blackwall and whitewall presentations. A tire that looks attractive on its own can still be the wrong visual statement for the class.

For the 1938 Nash in 700-16, the Firestone offering shown here is a 4.00 Inch Wide Whitewall bias-ply tire with a listed maximum load of 1800 pounds at 36 psi and a rim-width range of 4.50 to 5.50 inches. The BFGoodrich 700-16 is a Blackwall bias-ply tire with a listed maximum load of 1900 pounds at 36 psi and the same 4.50- to 5.50-inch rim-width range.

That makes the most visible difference the sidewall presentation, with the load figure and product weight providing secondary points of comparison. If your restoration calls for a bright formal prewar look, the Firestone whitewall may align with that goal. If you want a blackwall presentation while staying in the same basic fitment envelope, the BFGoodrich offers that path without changing wheel diameter or construction type.

1938 Nash tires can be suitable for highway use when they are the correct size, in good condition, and operated within their construction and service limits. The available 700-16 Avon tire carries an L speed rating, which corresponds to a 75 mph ceiling, while the other 700-16 offerings shown here are bias-ply tires without a listed speed letter in the provided markings. On a prewar Nash, the car's own braking, suspension, and steering condition often matters as much as the tire itself.

A sensible approach is to treat the tire, wheel, and vehicle as one system rather than focusing only on the sidewall code. Fresh, correctly fitted tires help, but they do not override eighty-plus-year-old chassis design or deferred maintenance. Before regular highway use, make sure the entire car is sorted and use speeds that respect both the tire's markings and the mechanical realities of a 1938 automobile.

Pressure on a 1938 Nash should be set by the size and the specific tire you are using, not by a one-pressure-fits-all rule. Among the available 700-16 products, BFGoodrich lists 1900 pounds at 36 psi and Firestone lists 1800 pounds at 36 psi. Those figures are tire ratings rather than a blanket recommendation that every 1938 Nash should always run at exactly that pressure in every condition.

Use the original Nash owner's literature or factory specification as the starting point for vehicle operating pressure, then compare that against the reproduction tire's rated limits. If your car uses a different size or a different product series, do not transfer numbers casually from one tire to another. Matching pressure to the actual tire and the car's intended load is the more reliable way to protect ride, wear, and handling.

Before a longer drive in a 1938 Nash, inspect each tire for cracking, cuts, bulges, irregular wear, and proper inflation, and include the spare in that check. Confirm that the mounted size matches the wheel and that the valve stems are in sound condition. On a prewar car, tire readiness is only one part of the equation, but it is one of the easiest and most important checks to perform before departure.

A longer outing is exactly when a minor tire issue can become a trip-ending problem. Once the tire check is complete, give the rest of the car the same level of attention, especially the brakes, cooling system, and wheel hardware. A 1938 Nash rewards careful preparation, and taking a few extra minutes before the drive is far easier than solving a roadside failure after the car is fully loaded.