1957 Fiat 600 Tires

The 1957 Fiat 600 uses two primary tire sizes: 520-12 in a bias-ply construction and 135R12 in a radial construction. Both sizes are associated with the model on a 12-inch rim, giving owners a traditional numeric bias-ply format and a Euro-metric radial format to consider.

That makes the main decision less about wheel diameter and more about the kind of tire you want on the car. A 520-12 keeps the older bias-ply sizing convention and appearance, while 135R12 moves into a radial format. It is still worth confirming the actual wheel setup on the car, especially if it has been modified or restored with replacement wheels.

The 1957 Fiat 600 uses a 12-inch rim diameter with both of its primary tire sizes, 520-12 and 135R12. That shared rim diameter simplifies the basic wheel-size question, because both the bias-ply and radial fitments center around the same 12-inch wheel size.

Rim diameter is only one part of fitment, though. Before choosing between the two sizes, it helps to confirm the wheel width and the car’s current setup, since older vehicles are often fitted with replacement wheels over time. That matters even more when considering a radial alternative, where wheel width and overall tire dimensions should be checked carefully.

Yes. Both the 1957 Fiat 600 Base and the 1957 Fiat 600 Multipla use the same two tire-size formats: 520-12 bias-ply and 135R12 radial. There is no separate sub-model-specific tire size split between those covered versions of the Fiat 600.

That consistency makes selection easier, because the choice comes down to construction and appearance rather than trim-specific sizing. A buyer can focus on whether the car should retain a traditional bias-ply look or move to a radial format. Even with shared fitment, checking the wheels already on the car is still smart, especially on a collector vehicle with an unknown service history.

On the 1957 Fiat 600, 520-12 is a bias-ply tire size. It uses the older numeric sizing convention, and it is the traditional-format fitment for owners who want the car to keep a more vintage tire presentation on its 12-inch wheels.

Choosing 520-12 usually points toward a restoration-oriented look, especially when comparing blackwall and wide whitewall versions. Bias-ply construction also differs from radial construction in feel and presentation, so mixing formats should be approached carefully. The wheel itself should be checked for width and condition before any replacement, particularly on an older compact car where wheel changes may have happened decades ago.

Radial equivalents for 520-12 include 125R12 and P125/75R12. The 125R12 is an 80-series metric radial equivalent, while P125/75R12 is a P-metric 75-series radial equivalent. Both are radial-format alternatives tied to the original 520-12 bias-ply size.

Those two options give the 1957 Fiat 600 owner different radial sizing conventions to compare rather than one automatic substitute. A recommended rim-width range of 4 to 5 inches applies to the equivalent mapping, and overall fitment should still be verified against the car’s wheel width, tire clearance, and intended use. That is especially important if the car no longer carries its original-style wheels.

Start by confirming the car’s actual wheel diameter and width, then compare the radial size being considered against the existing 520-12 bias-ply fitment. For a 1957 Fiat 600, radial alternatives connected to 520-12 include 125R12 and P125/75R12, and the wheel should fall within the relevant width range before moving forward.

Clearance at the fenders, suspension, and steering should also be reviewed, because a small car can be especially sensitive to dimensional changes. Tire age, wheel condition, and the overall state of the suspension deserve attention at the same time. A conversion can be worthwhile to consider, but it should be treated as a fitment evaluation rather than an automatic replacement.

The first consideration is whether the car will use the 520-12 bias-ply format or the 135R12 radial format, since both apply to the 1957 Fiat 600. After that, the decision shifts toward sidewall appearance, tire series, and the type of driving or presentation the car is meant to have.

A buyer focused on vintage style may prefer the traditional numeric bias-ply size, while someone wanting a radial-format tire may look to 135R12 instead. It also helps to compare the current wheel setup and the condition of the suspension and steering components before choosing. On a lightweight collector car, those details influence how appropriate a given tire choice will feel once installed.

Sidewall choices for the 1957 Fiat 600 include blackwall and wide whitewall, depending on the tire size and product selected. The 135R12 Firestone radial is offered as a blackwall, while the 520-12 BFGoodrich bias-ply options include both blackwall and a 2.00 inch wide whitewall version.

That makes sidewall style an important appearance decision, especially on a small European car where the tire is visually prominent. A blackwall gives a restrained, utilitarian look, while a wide whitewall creates a more stylized vintage presentation. The right choice depends on the character of the restoration and the period look you want, not just on basic size compatibility.

The available brands for the 1957 Fiat 600 are Firestone and BFGoodrich. Firestone appears in the 135R12 radial size through the F560 Radial series, while BFGoodrich covers the 520-12 bias-ply size in the Silvertown Classic Bias Ply series with more than one sidewall treatment.

Brand choice here is closely tied to construction and visual style rather than to a long list of overlapping products in the same exact format. That means it helps to decide first whether the car should wear a radial or a bias-ply tire. Once that is settled, the series and sidewall presentation become more useful comparison points than the brand name alone.

For a period-style 1957 Fiat 600, the 520-12 bias-ply size is the most natural starting point because it preserves the vintage numeric sizing format and traditional construction. Within that size, BFGoodrich bias-ply options give the car a more classic small-car presentation than a modern radial format would.

The final choice depends on whether the restoration leans toward a simple blackwall look or a more decorative wide whitewall treatment. Exact originality can vary by market, trim history, and restoration goal, so buyers pursuing a highly exact finish should compare tire appearance against marque-specific references. For many owners, though, staying with 520-12 keeps the overall look in the right historical neighborhood.

Tire construction changes the visual character of a restored 1957 Fiat 600 because a 520-12 bias-ply carries an older sizing language and a more traditional vintage presentation, while a 135R12 radial introduces a later radial-format look. Even when both fit the same 12-inch rim diameter, they do not present the car in exactly the same way.

That difference matters on a compact body where the tire and wheel opening are very visible. A restoration aimed at period style often starts by deciding whether the car should look authentically mid-century in spirit or slightly updated for road use. Sidewall treatment then becomes the finishing choice, with blackwall and wide whitewall options creating distinctly different visual results.

Yes. Even though the 1957 Fiat 600 uses 12-inch tire fitments, modifications can still affect which tire works well on the car. Replacement wheels, altered wheel widths, suspension changes, or body work around the wheel openings can all change how a 520-12 or 135R12 tire sits and clears.

That is why an owner should verify the actual wheel dimensions and inspect clearance at full steering lock and normal ride height before choosing a tire. Small cars often have less room for error than larger vehicles. A tire that matches the nominal size still needs to be compatible with the car’s current setup, especially after years of repairs or customization.

Before putting a 1957 Fiat 600 back on the road with new tires, inspect the wheels for damage, confirm that the tire size matches the wheel diameter, and look over the suspension and steering for looseness or wear. It also helps to check for any rubbing points around the fenders and inner wheel housings.

Tire pressure, valve condition, and proper seating on the rim deserve attention before the first longer outing. After the first few drives, recheck pressure and look for uneven wear or signs of contact. On a lightly used collector car, road readiness depends on the surrounding hardware as much as on the tires themselves, particularly if the car has sat for extended periods.

Tires on a collector 1957 Fiat 600 should be inspected regularly for air loss, cracking, cuts, bulges, and irregular tread wear, even if the car is driven only occasionally. Collector vehicles often age their tires through time and storage conditions rather than through high mileage, so visual condition matters as much as tread depth.

Proper inflation, clean storage, and protection from prolonged sunlight, moisture, and ozone sources can help preserve the tire over time. It is also wise to move or drive the car periodically so the tires are not left in one position for too long. Any older Fiat that has been sitting should have its tires and wheels checked carefully before returning to regular road use.