1971 Fiat 850 Tires

The 1971 Fiat 850 uses more than one primary tire size. Coupe, Sport, and Spider models use either 155R13 in radial construction or 560-13 in bias-ply construction, while the Sedan Special uses either 145R13 in radial form or 520-13 in bias-ply form. All of these fitments are built around a 13-inch rim.

The important step is confirming the exact sub-model before choosing a tire. A Coupe, Sport, or Spider should not automatically be matched to the Sedan Special sizes, and the reverse is also true. If the car has been modified, wheel width and actual wheel diameter should be checked before moving from one construction type or size family to another.

The 1971 Fiat 850 uses a 13-inch rim across its primary tire fitments. That applies whether the car is running 155R13, 560-13, 145R13, or 520-13, so the wheel diameter stays consistent even though the tire sizes differ by sub-model and construction type.

Wheel diameter is only part of the fitment picture. The 13-inch wheel still needs to be matched to the correct tire size for the specific Fiat 850 version, and wheel width also matters when comparing bias-ply tires with radial alternatives. On an older Fiat, it is smart to confirm the actual wheel currently on the car instead of assuming it remains original.

The 1971 Fiat 850 has multiple tire sizes because fitment changes by sub-model and by tire construction. The Coupe, Sport, and Spider use a larger pair of sizes, 155R13 radial or 560-13 bias-ply, while the Sedan Special uses the smaller 145R13 radial or 520-13 bias-ply combination.

That difference means tire selection should begin with the exact model designation, not just the year and make. It also helps explain why some buyers see both radial and bias-ply options for the same car family. Once the sub-model is confirmed, the next decision is whether the goal is traditional appearance, radial road use, or a restoration-oriented bias-ply setup.

560-13 is a bias-ply tire size for the 1971 Fiat 850 Coupe, Sport, and Spider. It is part of the vintage numeric bias-ply sizing system, where the leading number represents nominal section width and the final number identifies the 13-inch wheel diameter.

Choosing 560-13 keeps the car in a traditional bias-ply format and opens up sidewall choices such as narrow whitewall and wide whitewall. That can matter on a restoration-oriented car where appearance is part of the project. A radial alternative may also be considered, but wheel width, vehicle setup, and intended road use should be reviewed before changing construction.

Radial equivalents for 560-13 include 155R13 as an 80-series metric radial, P155/75R13 as a 75-series P-metric radial, and P155/70R13 as a 70-series P-metric radial. These provide three different radial-format comparison points for the bias-ply size used on 1971 Fiat 850 Coupe, Sport, and Spider models.

Each equivalent follows a different sizing convention, so the choice is not only about construction but also about profile style. A recommended rim-width range of 4 to 5 inches is associated with these radial equivalents. Before converting, compare the wheel width already on the car and make sure steering, suspension, and body clearances remain appropriate.

Start by confirming the Fiat 850 sub-model and original bias-ply size, since the Coupe, Sport, and Spider use 560-13 while the Sedan Special uses 520-13. Then compare the intended radial equivalent with the car's 13-inch wheel setup, paying close attention to wheel width and the tire size family being considered.

A radial equivalent should be treated as an alternative, not an automatic substitute. Clearance at the fender, suspension, and steering range should be checked, especially on a small car where even modest dimensional changes can matter. The vehicle's overall condition also counts, since worn suspension parts can affect how a different construction behaves on the road.

Start with the exact sub-model, because the Coupe, Sport, and Spider use different primary sizes than the Sedan Special. After that, decide whether the car should stay with a bias-ply setup for traditional presentation or use the radial size associated with that version of the 1971 Fiat 850.

Once the correct size is established, compare the available brands, tire series, sidewall appearance, and wheel-width compatibility where it is stated. A blackwall radial may suit a road-driven car, while a whitewall bias-ply may better match a restoration-focused project. The right choice depends on how the Fiat is used and how closely the tire should support the car's intended look.

Sidewall choices for the 1971 Fiat 850 include blackwall, narrow whitewall, and wide whitewall, depending on the tire size and construction. The radial offerings in 145R13 and 155R13 are blackwall, while the bias-ply sizes 520-13 and 560-13 open the door to several whitewall treatments.

That variety matters because sidewall style has a strong effect on the car's finished appearance. A blackwall radial tends to keep the look simple and purposeful, while narrow or wide whitewalls create a more period-style presentation. The best way to choose is to begin with the correct size for the specific Fiat 850 sub-model, then narrow the options by appearance.

Tire choices for the 1971 Fiat 850 include Michelin, Dunlop, Firestone, BFGoodrich, and Premium Sport. The radial sizes are represented by Michelin, Dunlop, and Firestone, while the bias-ply sizes bring in BFGoodrich, Firestone, and Premium Sport depending on whether the car uses the larger or smaller 13-inch fitment.

Brand choice should come after the correct size and construction have been settled. Some brands appear only in radial applications, while others are tied to whitewall bias-ply offerings that shape the car's visual character. Looking at the tire series and sidewall style within each correct size will usually be more useful than choosing by brand name alone.

For a period-style 1971 Fiat 850, the bias-ply sizes are the natural starting point. Coupe, Sport, and Spider models use 560-13 in bias-ply form, while the Sedan Special uses 520-13. Those sizes preserve the vintage sizing format and give access to whitewall treatments that shape the car's overall presentation.

The final choice depends on how authentic-looking the car needs to be and which sub-model is being restored. A buyer focused on exact historical detail should compare tire appearance with marque references, photos, or other vehicle-specific documentation. If the goal is a broadly restoration-oriented look rather than exact originality, the available bias-ply options provide useful visual flexibility.

Tire construction changes both the look and character of a restored 1971 Fiat 850. A bias-ply tire such as 560-13 or 520-13 gives the car a more traditional vintage presentation, especially when paired with whitewall sidewall treatments, while the radial sizes 155R13 and 145R13 present a more modern blackwall appearance.

That visual difference can be as important as the fitment itself on a small European collector car. Buyers restoring a Fiat 850 for shows or period style often start with the correct bias-ply size, then evaluate sidewall width and brand presentation. Buyers prioritizing road use may still prefer radial construction, even if it shifts the car away from a more vintage look.

Yes, modifications can affect tire fitment on a 1971 Fiat 850 even though all primary sizes use a 13-inch rim. Aftermarket wheels, altered wheel width, suspension changes, lowering, or bodywork repairs can change how much room is available for the correct tire size or for a radial equivalent being considered.

That matters especially on a compact car with tight clearances. A Fiat 850 that no longer has its original wheels should be measured before any tire is selected, and steering clearance should be checked through full lock. Staying with the proper sub-model size is still the foundation, but modifications can change whether a particular tire choice remains practical.

Before driving a 1971 Fiat 850 on new tires, inspect the wheels for correct diameter and condition, confirm that the tires are mounted in the proper sub-model size, and check inflation pressure, valve stems, and overall installation quality. It also helps to make sure the tires clear the fenders and suspension through the full steering range.

Older collector cars deserve an extra walk-around before the first real drive. Look for rubbing, uneven stance, loose wheel hardware, and any sign of interference after the car has rolled and settled. On a small rear-engine car like the 850, suspension wear can also influence how a fresh set of tires behaves, so a general chassis inspection is worthwhile.

Tires on a collector 1971 Fiat 850 should be checked regularly for air loss, sidewall cracking, cuts, bulges, and tread condition, even if the car is driven only occasionally. Collector cars often age their tires through time and storage rather than mileage, so appearance alone is not enough to judge readiness for road use.

Proper storage helps preserve both bias-ply and radial tires. Keep the Fiat away from prolonged sunlight, excess heat, moisture, and ozone sources, and inspect the tires before each outing if the car sits for long periods. Regular pressure checks and periodic visual inspection of the wheels and suspension can prevent a small storage issue from becoming a road-use problem.