1973 Fiat Tire Fitment Guide

1973 Fiat vehicles use five sizes across three model lines: 155R13, 560-13, 165R13, 600-13, and 145R13. The 124 uses 155R13, 560-13, 165R13, and 600-13; the 128 uses 145R13 and 155R13; and the 850 uses 155R13 and 560-13. Every one of those sizes mounts on a 13-inch wheel. Rim-width guidance varies by size, with examples including 4.00 to 5.50 inches for 155R13, 3.50 to 4.50 inches across the available 560-13 products, 4.50 to 6.00 inches for 165R13, 4.00 to 4.50 inches for 600-13, and 4.00 to 5.00 inches for 145R13 where specified.

That means year and make alone are not enough for a confident choice on a 1973 Fiat. Start by identifying whether you have a 124, 128, or 850, then compare the tire size already on the car with the wheel width you actually have. The 13-inch diameter is shared across the range, but width and construction still matter. If your goal is restoration accuracy, the bias-ply sizes deserve separate consideration from the radial sizes. If your goal is regular driving, stay focused on the exact model-size pairing before narrowing down brand or sidewall style.

On a 1973 Fiat, 560-13 is a numeric bias-ply size. The 560 portion is the traditional nominal section-width style used in older American and European sizing systems, and the 13 is the wheel diameter in inches. Unlike a modern metric radial code, it does not use an R to identify radial construction, so this format indicates a bias-ply tire. In the 1973 Fiat range, 560-13 applies to the 124 and 850 rather than to every model.

That matters because a 560-13 is not just a different label for a radial alternative. It changes the construction type, the look of the sidewall, and often the steering and ride character you feel at lower speeds. Whitewall options are also available in this size, which can make it especially relevant for a period-style presentation. Before choosing 560-13 for a 1973 Fiat, confirm that your wheel width matches the tire's range and decide whether you want the driving feel of a bias-ply tire or the more familiar road manners of a radial.

No, 1973 Fiat models do not all use the same tire size. The 155R13 radial is the one size shared by the 124, 128, and 850, but the other sizes are model-specific. The 124 alone reaches 165R13 and 600-13, the 128 alone uses 145R13, and the 560-13 bias-ply size is shared only by the 124 and 850. All of them stay within the same 13-inch rim diameter, but width and construction differ from one model application to another.

For a buyer, that means the first decision is not brand or sidewall style but model identification. A 124 owner has the widest spread of fitments to sort through, while a 128 owner is choosing between two radial sizes and an 850 owner is usually deciding between radial and bias-ply character. If your Fiat has changed hands a few times, checking the existing tire code and wheel width before ordering is especially worthwhile. Model-specific selection helps avoid mixing a correct 13-inch diameter with the wrong section width or construction.

For a 1973 Fiat that accepts both sizes, the choice between 155R13 and 560-13 is mainly a choice between radial and bias-ply construction rather than a change in wheel diameter. The 155R13 is a radial blackwall size shared across the 124, 128, and 850, while the 560-13 is a bias-ply size used on the 124 and 850. The radial option brings a later-style European road-tire format, while the bias-ply option preserves an earlier presentation with available whitewall styling.

If your priority is period appearance, especially on a show-oriented 124 or 850, the 560-13 will usually align more closely with a vintage bias-ply look. If your priority is road use with a radial casing and a more familiar modern feel, 155R13 is the more natural choice. Neither size should be treated as interchangeable across the entire 1973 Fiat line, because the 128 does not use 560-13. Confirm the model first, then match the construction to how you plan to use the car.

1973 Fiat tire options split cleanly by size and construction when it comes to sidewall styling. The radial sizes 145R13, 155R13, and 165R13 are available as blackwalls. The bias-ply sizes 560-13 and 600-13 open up whitewall choices, including narrow whitewall and wide whitewall versions. That gives the 124 and 850 more visual flexibility than the 128, which stays in blackwall radial territory with the sizes covered here.

For a 1973 Fiat, sidewall style is often as much a restoration decision as a fitment decision. A blackwall radial generally suits a European sporting or factory-style road look, especially on compact Italian cars from the early 1970s. A whitewall bias-ply tire can create a distinctly period custom or U.S.-market visual effect, particularly on cars restored to match an era-specific presentation. If authenticity matters for judging or marque-club expectations, compare your intended sidewall style against period photos and event standards before making the final selection.

Four brands cover the 1973 Fiat sizes here: Michelin, Dunlop, BFGoodrich, and Firestone. Michelin and Dunlop appear in the radial 155R13 and 165R13 sizes, Michelin and Firestone cover 145R13, and BFGoodrich plus Firestone cover the bias-ply 560-13 size. BFGoodrich alone appears in 600-13. The result is a mix of European-style radial offerings and classic-brand bias-ply choices depending on the specific Fiat model and size.

That brand spread is useful because the right choice often follows the tire format rather than the badge on the sidewall. Owners focused on European radial character will naturally spend more time comparing Michelin and Dunlop in the metric 13-inch sizes, while owners restoring a bias-ply 124 or 850 will compare BFGoodrich and Firestone whitewall offerings. Before narrowing to a brand, settle the size and construction first. Once that is done, sidewall style, load figure, and rim-width compatibility become the practical tie-breakers.

Rim-width requirements on 1973 Fiat tires depend on the exact size. The 155R13 radial fits 4.00 to 5.50-inch rims where specified, 560-13 bias-ply products span 3.50 to 4.50-inch rims depending on brand and version, 165R13 radial fits 4.50 to 6.00-inch rims, 600-13 bias-ply fits 4.00 to 4.50-inch rims, and 145R13 radial fits 4.00 to 5.00-inch rims where that range is stated. All of those sizes use a 13-inch wheel diameter, but width suitability changes from one tire to another.

That is why wheel diameter alone is not enough when setting up a 1973 Fiat. A tire may mount on a 13-inch wheel but still be a poor match if the wheel is too narrow or too wide for the casing. This matters most on the 124, since it spans the broadest range of section widths in both radial and bias-ply form. Measure the wheel you actually plan to use, compare it against the tire's approved width range, and avoid assuming that one 13-inch Fiat wheel automatically suits every 13-inch Fiat tire.

Inner-tube requirements for 1973 Fiat tires vary by product and by size. Several radial products in 145R13, 155R13, and 165R13 are marked TL, which indicates tubeless construction, while others in those same sizes do not carry a tube designation in the size marking. The bias-ply products in 560-13 and 600-13 also do not all carry a tube marker in the size code. Because of that variation, tube use should be confirmed against the exact tire and the wheel condition rather than assumed from size alone.

For a practical setup, the wheel itself matters just as much as the tire marking. A sound tubeless-compatible wheel may allow a TL-marked radial to run without a tube, while an older wheel with surface issues or a design intended for tube service may push the decision the other way. On a 1973 Fiat that sees occasional collector use, tube choice also affects how you inspect valve stems and monitor air retention. Treat tube use as an exact-product and exact-wheel question, not a blanket rule for the whole year and make.

Original 1973 Fiat wheels can potentially be used with multiple tire sizes because every size in this year-make group mounts on a 13-inch rim. That said, wheel diameter compatibility is only the first step. The available tires span different approved rim-width ranges, from narrow bias-ply fitments such as 560-13 up to wider radial fitments such as 165R13. A wheel that suits one of those sizes may not automatically be ideal for another, even though the bead seat diameter matches.

This question comes up most often with the 124, since it has four distinct size choices. If the car still has its original wheels, measure the width and compare that number to the range recommended for the tire you want to use. That approach preserves the wheel while keeping the casing in its intended working shape. It also helps avoid steering feel, tread profile, and appearance issues that can come from stretching a wide tire onto a narrow rim or pinching a tire beyond its intended fit range.

A stored 1973 Fiat should be kept away from direct sunlight, excess moisture, and ozone sources such as electric motors, battery chargers, welders, and running compressors. Clean, dry flooring and stable temperatures help both radial and bias-ply tires age more gracefully. If the car sits for long periods, moving it occasionally or supporting it to reduce constant load on one contact patch can help. Bias-ply tires used on some 1973 Fiat applications are generally more prone to temporary flat-spotting during static storage than radial tires.

Those habits matter because many collector Fiats are driven infrequently, and tires often age out before they wear out. Storage damage usually begins as sidewall checking, tread hardening, or persistent flat spots rather than dramatic tread wear. A simple routine of proper inflation, covered indoor storage, and occasional repositioning does more for long-term tire condition than most owners expect. If your Fiat spends winters parked, inspect the sidewalls carefully before the first spring drive and do not assume low mileage means the tires are still healthy.

Tires on a 1973 Fiat are usually evaluated by age before they are judged by mileage. A good rule for collector use is to inspect them closely once they reach the five- to seven-year range and to treat about ten years as the point where replacement deserves serious consideration regardless of tread depth. The DOT date code, if present, is the quickest way to establish age. That matters even more on lightly used small classics, where tread can look serviceable long after the rubber has begun to harden.

A radial 155R13 or 165R13 with plenty of tread is not automatically road-ready if the casing is old, and the same is true for a bias-ply 560-13 or 600-13 preserved mainly for show use. Age affects grip, flexibility, and resistance to cracking. If a 1973 Fiat has been parked for years or passed through several owners, checking the date code should be one of the first steps before any meaningful road use. Collector mileage is simply too low to use tread wear alone as the deciding factor.

Tires on a 1973 Fiat should be inspected before every drive and again before any longer outing. Look for sidewall cracking, bulges, cuts, embedded objects, uneven tread wear, and signs that the tire is losing air. Pressure should be checked cold, not after driving. If your chosen tire setup uses tubes, valve stems and air retention deserve extra attention because a collector car can sit long enough for a slow issue to go unnoticed.

Frequent inspection is especially important on small, lightweight classics because they can feel surprisingly normal even when a tire is aging poorly. A short local drive may not reveal a weakened sidewall or a tire that has gone out of round after storage. Spending a few minutes on a walk-around is far easier than dealing with a failure on the road. Include the spare in the routine as well, since many vintage cars still carry an old unused spare that looks fine but is no longer trustworthy.

For a 1973 Fiat 124, original-era fitment expectations center on 13-inch tires, with both radial and bias-ply sizes appearing in period-style replacements for the model. The 124 uses 155R13, 560-13, 165R13, and 600-13 in the fitments covered here. By 1973, radial tires were well established in European passenger-car use, especially on compact and sporting models, while bias-ply construction still remained relevant for restoration-style presentation. Original brand fitment can vary by market and delivery specification, so construction type and size are the more dependable starting points.

For a faithful restoration, match the tire first to the exact version of the 124 you are preserving, then to the type of authenticity you want to present. A road-focused European look may point you toward one of the radial sizes, while a show presentation with period sidewall styling may justify a bias-ply choice. Since export-market details and trim expectations can differ, marque clubs, factory literature, and period photography are valuable final checks. That extra research helps separate what fits a 1973 Fiat 124 from what actually looks right on your particular car.

Correct tire fitment absolutely matters when showing a 1973 Fiat. Judges and knowledgeable enthusiasts often notice whether the car carries the right overall size family, the right construction type for the restoration goal, and a sidewall style that matches the era and market presentation. A modern-style radial on a car judged for strict originality can draw attention, just as an oversized or overly stylized whitewall can look out of place on a compact Italian car if the event expects factory-type appearance.

The level of scrutiny depends on the event. A casual local show may focus more on overall condition, while marque-oriented or concours-style judging may look more closely at size, sidewall appearance, and period correctness. That is why it helps to decide early whether your 1973 Fiat is being restored for authenticity, club touring, or a personalized period look. Once that goal is clear, the tire decision becomes much easier. Event guidelines and Fiat club advice are the best final arbiters when originality standards are important.

For a 1973 Fiat, the Michelin XAS-FF and Dunlop SP Sport Aquajet overlap in the radial 155R13 and 165R13 sizes, and both families use blackwall construction with H speed ratings up to 130 mph in the examples here. Michelin versions in 155R13 and 165R13 carry TL markings, while the Dunlop examples do not show a tube designation in the same way. In 165R13, the Dunlop example also carries a 1,047-pound maximum load figure. Rim-width guidance appears on the Michelin examples at 4.00 to 5.50 inches in 155R13 and 4.50 to 6.00 inches in 165R13.

In practical terms, both tire lines live in the same European-style radial lane for a 1973 Fiat, so the comparison is about details rather than about radically different use cases. Tube marking, published load information, and the exact wheel width on the car may help break the tie. Owners trying to preserve a distinctly European period-correct appearance often compare these two families closely because both feel appropriate to the character of a small Italian car from the era. Check the exact size first, then compare the tire's casing details and wheel-width compatibility.

1973 Fiat tires can be appropriate for highway driving when they are the correct size, in sound condition, and used within their rated limits. The radial 145R13, 155R13, and 165R13 offerings here include H speed ratings, which carry a ceiling of 130 mph. The bias-ply sizes do not show matching modern speed-letter markings in the same way, so they should be approached with the expectations normally given to vintage-style bias-ply construction. On a 1973 Fiat, the car's own brakes, suspension, alignment, and age-related mechanical condition are usually more relevant to normal highway confidence than headline tire speed capability.

That means safety is not just about choosing a radial over a bias-ply tire or picking the highest letter on the sidewall. Tire age, pressure retention, balance, and wheel condition all matter, especially on a small classic that may spend long stretches parked. A healthy 1973 Fiat on properly selected tires can be enjoyable on modern roads, but it should still be driven with the pace and mechanical sympathy appropriate to a 1970s compact. Before sustained highway use, inspect the whole car, not just the tread.

Inflation pressure on 1973 Fiat tires should begin with the vehicle manufacturer's recommendation for the exact model and then be checked against the tire's own rated maximum-pressure information where it is published. Among the available sizes here, 560-13 carries 850 pounds at 30 psi, 600-13 carries 1,010 pounds at 32 psi, and one 145R13 example carries 825 pounds at 44 psi. Those figures are not universal running pressures for every 1973 Fiat tire; they are size- and product-specific ratings tied to that individual casing.

The practical rule is simple: do not transfer a pressure number from one size or construction type to another. A 560-13 bias-ply tire and a 165R13 radial do not necessarily want the same inflation approach, even though both fit 13-inch wheels. Start with the owner's manual or factory placard for your 124, 128, or 850, then compare that guidance with the tire's own limits and intended use. If the car carries a non-original wheel or an unusual restoration setup, pressure should be reviewed more carefully before regular driving.

Before a longer drive in a 1973 Fiat, inspect every tire for cracking, cuts, bulges, uneven wear, and proper cold inflation. Check that the valve stems are sound, and pay extra attention if your setup uses tubes or if the tube status varies by product in the size you chose. The spare should be examined as carefully as the road tires. On a collector car, the tire that has not touched the road in years can be the least trustworthy one on the vehicle.

A longer trip also calls for a broader mechanical once-over, because tires are only one part of the readiness picture on an older Fiat. Verify brake feel, fluid levels, wheel fastener security, steering response, and any age-related rubber parts that could affect the drive. Tires often get the first glance, but they work in concert with the rest of the chassis. A careful pre-drive inspection reduces the chance that a small issue becomes a roadside problem and helps the car feel as composed as it should on the journey.