The 1957 Fiat 1400 belongs to Fiat’s postwar family-sedan era, when European cars emphasized efficiency, tidy proportions, and road manners suited to narrower streets and modest engine output. That character makes tire choice especially important, because a small change in size or construction can noticeably affect stance, steering feel, and overall presentation. This model uses four distinct 14-inch tire fitments across its covered configurations: 165R14 and 5.90-14 for the 1400 A & B, and 175R14 and 6.40-14 for the 1400 A & B Diesel. The decision is not just radial versus bias-ply, but also which sub-model you have and whether you want a traditional look or a more modern road-going radial setup.
Which Tire Size Is Right for The 1957 Fiat 1400
The 1957 Fiat 1400 uses four tire sizes, and the correct one depends first on the exact sub-model. All four fitments use a 14-inch rim, but the covered A & B models and the A & B Diesel models do not share the same radial or bias-ply sizes. Before choosing a tire, confirm which version of the car you have and whether you want to stay with the original-style construction approach or move to the radial option for that same configuration.
165R14 is a Euro-metric radial size, with 165 indicating nominal section width in millimeters, R showing radial construction, and 14 identifying the wheel diameter in inches. On the 1957 Fiat 1400, this size serves the 1400 A & B radial fitment and gives a distinctly European period-style tire choice on a 14-inch rim. Available options include blackwall tires from Pirelli, Michelin, and Vredestein across series such as Cinturato CA67, Michelin XAS, and Sprint Classic. It is the size to evaluate when the car is set up for the narrower A & B radial specification and a classic road-use radial is the goal.
5.90-14 is a numeric bias-ply size, with 5.90 representing the nominal section width in inches and 14 indicating the wheel diameter. On the 1957 Fiat 1400, this is the bias-ply fitment associated with the 1400 A & B configuration, making it the traditional-construction choice for owners who want to preserve an earlier driving character and appearance. Numeric bias-ply sizing is familiar on many period European and American vehicles, and it should be matched to the correct sub-model rather than treated as interchangeable with the larger Diesel fitment. It is the right size to consider when maintaining the A & B car in a restoration-oriented bias-ply format.
175R14 is a Euro-metric radial size, with a 175-millimeter nominal section width, radial construction, and a 14-inch rim diameter. For the 1957 Fiat 1400, this size belongs to the 1400 A & B Diesel radial setup, making it distinct from the smaller 165R14 used on the non-diesel A & B version. Blackwall choices are available from Michelin and Vredestein, including Michelin XAS, Sprint Plus, and Sprint Classic series. It is the size to review when the car is the Diesel variant and you want a radial tire that stays within the correct 14-inch fitment family for that configuration.
6.40-14 is a numeric bias-ply size, with 6.40 expressing nominal section width in inches and 14 indicating the wheel diameter. On the 1957 Fiat 1400, this is the bias-ply fitment tied to the 1400 A & B Diesel, so it should not be confused with the smaller 5.90-14 used on the standard A & B models. Bias-ply construction suits buyers who want a more traditional tire presentation and period-style construction for a restoration-oriented Diesel car. This size is the one to verify when keeping the Diesel configuration aligned with its proper bias-ply fitment path.
Sub-model fitment matters on the 1957 Fiat 1400 because the covered configurations do not all use the same tire size. Both versions use 14-inch wheels, but the standard A & B and the A & B Diesel each have their own radial and bias-ply pairings, so identifying the exact sub-model comes first.
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1957 Fiat 1400 A & B
The 1957 Fiat 1400 A & B uses 165R14 in radial form or 5.90-14 in bias-ply form on a 14-inch rim. That gives the owner a clear choice between a classic European radial setup and a more traditional bias-ply presentation, with size confirmation centered on the non-diesel A & B configuration.
The 1957 Fiat 1400 A & B (Diesel) uses the larger 175R14 radial size or 6.40-14 in bias-ply construction, both on 14-inch wheels. Tire selection for the Diesel version starts with confirming that larger fitment, then deciding whether the goal is period-style bias-ply appearance or a radial road-use setup.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Best 1957 Fiat 1400 Tires for Sale
Available 14-inch radial choices for the 1957 Fiat 1400 center on 165R14 and 175R14 blackwall tires from Pirelli, Michelin, and Vredestein. The product grid lets you compare series such as Cinturato CA67, Michelin XAS, Sprint Classic, and Sprint Plus, along with construction details and rim-width specifications where stated.
These FAQs focus on the exact tire sizes used on the 1957 Fiat 1400, how fitment changes between A & B and A & B Diesel models, and how to choose between bias-ply character, radial options, and restoration-oriented appearance.
Tire Size & Fitment
What tire size fits a 1957 Fiat 1400?
The 1957 Fiat 1400 does not use one universal tire size across every covered configuration. The 1400 A & B uses 165R14 in radial form or 5.90-14 in bias-ply form, while the 1400 A & B Diesel uses 175R14 in radial form or 6.40-14 in bias-ply form. All of these fitments use a 14-inch rim.
The first step is identifying whether the car is an A & B or an A & B Diesel, because that determines which pair of sizes applies. After that, the decision becomes whether to stay with the traditional bias-ply fitment or choose the radial size used for that same sub-model and wheel diameter.
What size rim does a 1957 Fiat 1400 use?
The covered tire fitments for the 1957 Fiat 1400 all use a 14-inch rim diameter. That includes 165R14, 5.90-14, 175R14, and 6.40-14, so the wheel diameter stays consistent even though the tire sizes vary by sub-model and construction type.
Rim diameter is only one part of the fitment picture, so confirming the sub-model still matters. It also helps to verify the actual wheel on the car, especially if it has been changed over the years, because a replacement tire still needs the correct width relationship and enough clearance for the vehicle’s current setup.
Do all 1957 Fiat 1400 sub-models use the same tire size?
No. The 1957 Fiat 1400 A & B uses 165R14 or 5.90-14, while the 1957 Fiat 1400 A & B Diesel uses 175R14 or 6.40-14. Both sub-model groups remain within the same 14-inch wheel diameter, but the Diesel fitments are the larger pair.
That difference means the buyer should not choose by wheel diameter alone. Start by confirming the exact sub-model, then select the matching radial or bias-ply size for that version of the car. This keeps the purchase focused on the proper fitment family rather than mixing standard and Diesel tire sizes.
Choosing the Right Tire
What should I consider when choosing a 165R14 or 175R14 tire for a 1957 Fiat 1400?
Begin with the correct sub-model, because 165R14 belongs to the 1400 A & B and 175R14 belongs to the 1400 A & B Diesel. From there, compare the available radial options by tire series, brand, sidewall treatment, and any stated rim-width or load details that match the wheel and intended use of the car.
The available 14-inch radial choices are all blackwall tires, but they vary in character through series such as Pirelli Cinturato CA67, Michelin XAS, Vredestein Sprint Classic, and Vredestein Sprint Plus. A restoration-oriented owner may care most about period-style presentation, while a regular road-use owner may focus more on wheel compatibility and the overall setup.
What sidewall styles are available for 1957 Fiat 1400 tires?
The available radial products for the 1957 Fiat 1400 are blackwall tires. That applies across the listed 165R14 and 175R14 options from Pirelli, Michelin, and Vredestein, giving the car a clean European look that suits many postwar sedan restorations and driver-quality presentations.
Sidewall style affects appearance more than fitment, but it still plays a big role in how the finished car looks. A buyer choosing tires for a preserved or restored Fiat should consider whether a plain blackwall presentation matches the intended era feel, while still confirming the proper size for the specific A & B or Diesel configuration.
What brands offer tires for the 1957 Fiat 1400?
Pirelli, Michelin, and Vredestein all offer radial tire options for the 1957 Fiat 1400’s applicable 14-inch sizes. The 165R14 selection includes Pirelli Cinturato CA67, Michelin XAS, and Vredestein Sprint Classic, while the 175R14 selection includes Michelin XAS, Vredestein Sprint Plus, and Vredestein Sprint Classic.
Brand choice should come after confirming the correct size for the exact sub-model. Once that is settled, compare the available series and any stated rim-width, weight, or load details that matter to the way the car will be used. The goal is choosing within the right fitment, not treating every 14-inch radial as the same.
Restoration & Appearance
Which tire should I choose for a period-style 1957 Fiat 1400?
A period-style choice starts with using the correct size for the exact sub-model, then deciding whether the car should remain in its bias-ply fitment family or use its corresponding radial size. The A & B uses 5.90-14 or 165R14, while the A & B Diesel uses 6.40-14 or 175R14.
Bias-ply construction usually supports a more traditional presentation, while the Euro-metric radial options keep the car in an era-appropriate European tire format. When exact originality matters, it is worth checking marque-club guidance or other vehicle-specific historical references so the finished look matches the way the individual car is being restored.
How does tire construction affect the appearance of a restored 1957 Fiat 1400?
Tire construction changes more than ride and steering feel on a restored 1957 Fiat 1400; it also changes the visual character of the car. A bias-ply tire such as 5.90-14 or 6.40-14 gives a more traditional presentation, while 165R14 and 175R14 radials create a later, more road-going European look.
That makes construction part of the restoration decision, not just a mechanical detail. Owners who value a traditional stance and period-style impression often stay with the bias-ply fitment for their sub-model, while those planning more regular driving may prefer the radial size used for the same version of the Fiat.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1957 Fiat 1400?
Yes. Even though the 1957 Fiat 1400 uses 14-inch tire sizes within its covered fitments, changes to wheel width, wheel offset, suspension height, or body clearance can affect how a tire sits and turns on the car. That matters whether the car is using the A & B sizes or the larger Diesel sizes.
A car that still has its original-style wheel and suspension layout is easier to match to the intended fitment. If the Fiat has aftermarket wheels or altered suspension components, check wheel dimensions, steering clearance, and fender space before choosing between 165R14, 5.90-14, 175R14, or 6.40-14.
What should I inspect before driving a 1957 Fiat 1400 on new tires?
Before driving a 1957 Fiat 1400 on new tires, inspect the wheels for correct diameter and condition, confirm the tires match the proper sub-model size, and make sure the tires seat correctly and hold pressure. It also helps to look over the valve stems, wheel hardware, and any signs of rubbing during steering or suspension movement.
A collector-era Fiat often sits for long periods, so the rest of the chassis deserves attention too. Check alignment condition, steering play, suspension wear, and brake operation before any real road use. A properly mounted tire can still behave poorly if the surrounding components are worn or the car has unresolved handling issues.
How should 1957 Fiat 1400 tires be maintained on a collector car?
Collector-car tire care for a 1957 Fiat 1400 starts with regular pressure checks, visual inspections, and clean storage conditions. Look for sidewall cracking, cuts, bulges, irregular tread wear, or slow air loss, and do not assume low mileage means a tire is automatically ready for road use after long periods of sitting.
Storage habits matter on a lightly used Fiat because heat, sunlight, moisture, and ozone exposure all work against tire condition over time. Moving the car occasionally can help avoid long-term flat spotting, and a brief inspection before each outing helps catch aging or clearance problems before they turn into a roadside issue.
