1958 Saab Tire Fitment Guide

1958 Saab vehicles use three tire sizes across two model groups. The 1958 Saab 750 & 850 GT uses 155R15 radial tires. The 1958 Saab 92 & 93 uses either 145R15 radial tires or 5.20-15 bias-ply tires. All of those sizes mount on 15-inch rims, and where published rim-width guidance exists, 155R15 products fit 4.00 to 5.50-inch rims while 145R15 products fit ranges from 3.50 to 5.00 inches depending on the tire.

That means year and make alone are not enough for a correct selection on a 1958 Saab. You need to identify the model first, then decide whether your 92 or 93 is staying with a more traditional bias-ply setup or moving to a radial format. On a 750 or 850 GT, the decision is simpler because the size itself is model-specific. Before ordering, compare the tire size on the car now with the wheel you actually have, especially if the car has been restored or modified at some point in its life.

On a 1958 Saab, 145R15 is a Euro-metric radial size. The 145 indicates a nominal section width of 145 millimeters, the R identifies radial construction, and the 15 is the wheel diameter in inches. In this older metric format, the aspect ratio is not written into the code, but it is commonly treated as an 80-series profile. That size belongs to the 1958 Saab 92 & 93 rather than the 750 & 850 GT.

The practical value of understanding 145R15 is that it tells you this is a later-style radial sizing system, not an older inch-based bias-ply size. For many drivers, that means a 92 or 93 can be set up with more modern radial behavior while still keeping a narrow, period-appropriate footprint. When comparing products in 145R15, also pay attention to sidewall appearance, because both blackwall and wide whitewall versions exist and can change the look of the car even though the nominal tire size stays the same.

On a 1958 Saab, 5.20-15 is a numeric bias-ply tire size. The 5.20 refers to the nominal section width in inches, and the 15 is the wheel diameter in inches. Unlike a radial metric code, there is no R in the size because this format belongs to bias-ply construction. That size applies to the 1958 Saab 92 & 93 and not to the 750 & 850 GT.

Knowing that 5.20-15 is an inch-based bias-ply size helps you avoid mixing it up with the 145R15 radial alternative simply because both fit 15-inch wheels. The two formats can give the car a different look and driving character, especially on a light early Saab. If your goal is a more original late-1950s presentation, 5.20-15 is the size format most aligned with that period. If the car is being driven more regularly, compare it against the radial option with your restoration priorities in mind.

No, 1958 Saab models do not all use the same tire size. The 1958 Saab 750 & 850 GT uses 155R15 radial tires, while the 1958 Saab 92 & 93 uses either 145R15 radial or 5.20-15 bias-ply tires. All of those are 15-inch fitments, but the sizing and construction split by model group. That makes 1958 Saab a case where the wheel diameter is shared but the tire choice is not universal across the make.

For a buyer, that means identifying the model is more important than assuming any narrow 15-inch tire will be appropriate. The 750 and 850 GT sit in their own size category, while the 92 and 93 allow a construction choice within their own fitment. If you are looking at a restored car, also inspect what is fitted now rather than relying on appearance alone. Early Saab cars are often small enough that several narrow tires can look plausible at a glance, even when they are not the right match for the model.

For a 1958 Saab 92 or 93, the choice between 145R15 and 5.20-15 is mainly a choice between radial and bias-ply construction. The 145R15 is a radial size offered in blackwall and wide whitewall versions from multiple brands, while 5.20-15 is a bias-ply size for the same model family. Radial and bias-ply tires can change steering feel, straight-line tracking, and overall road character, even when both are appropriate to the same vehicle family.

Owners focused on a more original late-1950s presentation often lean toward the bias-ply size, while owners planning more regular road use often prefer the radial option. The better choice depends on how your Saab will be used and what standard of originality you want to preserve. Keep the decision model-specific: the 750 and 850 GT use 155R15, so this comparison only applies to the 92 and 93. A good next step is to decide whether appearance and judging goals or road-going behavior carries more weight for your car.

1958 Saab tires are available in more than one sidewall style, but the choices depend on size. The 155R15 tires used on the 750 & 850 GT are offered in blackwall form. The 145R15 tires used on the 92 & 93 are available in both blackwall and wide whitewall versions. That means sidewall appearance is part of the buying decision for a 92 or 93, while the GT models stay within a blackwall presentation in the available 155R15 offerings.

For a Scandinavian compact of this era, blackwalls generally align most naturally with the understated European look many owners want, especially on performance-leaning or export-style presentations. A wide whitewall can still be attractive if you are after a more personalized period appearance on a 92 or 93. The important point is to separate visual style from fitment: the sidewall treatment changes the look, but the tire still needs to match the correct model and size. If your Saab is being prepared for shows, check your event's standards before making sidewall style part of the final decision.

Several brands offer tires for 1958 Saab vehicles, with brand availability depending on the size. In 155R15 for the 750 & 850 GT, available brands include Firestone and Michelin. In 145R15 for the 92 & 93, available brands include Firestone, Michelin, and BFGoodrich. Those choices are all radial products in the listed sizes, while the 5.20-15 bias-ply fitment for the 92 & 93 remains a separate size category to confirm when you are shopping by model.

Brand choice matters less than getting the correct size, construction, and sidewall style for how your Saab will be used. Once those basics are settled, the brand roster gives you room to match the visual character and technical features you prefer. Michelin offerings, for example, appear in more than one specification within these Saab sizes, while Firestone and BFGoodrich add additional period-style options in radial form. Compare each tire as its own product rather than assuming all tires in the same size are interchangeable in tube status, speed rating, or intended character.

Published rim-width guidance for 1958 Saab tires varies by size and sometimes by product within the same size. In 155R15, listed fitments span 4.00 to 5.50-inch rim widths. In 145R15, listed fitments run from 3.50 to 5.00 inches on some products and 4.00 to 5.00 inches on others. All of the listed Saab sizes use a 15-inch rim diameter, but the acceptable rim width still needs to match the specific tire you choose.

That matters because two tires with the same nominal size can still have slightly different approved wheel-width windows. If your Saab is still on original wheels, measure them or verify their width before committing to a product, especially if you are choosing between multiple radial options. If the car has aftermarket or replacement wheels, the need to confirm grows even more important. Staying within the tire maker's approved rim-width range helps preserve intended profile shape and reduces the chance of fitment problems that are easy to miss on a narrow vintage tire.

Inner-tube requirements on 1958 Saab tires depend on the specific tire, not just the size. In 155R15, both tubeless and tube-type products are available, so tube status varies by product. In 145R15, tubeless examples are present. That means you cannot assume every radial in these Saab sizes is the same in how it is marked or intended to be fitted, even when the dimensions are similar.

The right approach is to match the tire's marking to the wheel and valve-stem setup you are actually using. If your Saab still has original-style wheels, inspect their condition carefully and verify whether the wheel itself is appropriate for tubeless use. If you choose a tube-type tire, use the correct tube and flap arrangement where applicable rather than improvising with whatever is on hand. Tube decisions are easy to overlook during restoration, but they affect installation details, valve-stem choice, and long-term reliability on a lightly used collector car.

All listed 1958 Saab tire sizes share a 15-inch rim diameter, so they are in the same basic wheel-diameter family. That said, they are not interchangeable across all models just because the wheel diameter matches. The 155R15 belongs to the 750 & 850 GT, while the 145R15 and 5.20-15 belong to the 92 & 93. Where radial rim-width guidance is published, the acceptable width also changes by size and by some individual products.

In practice, original wheels can often remain part of the equation, but the wheel should still be checked against the specific tire selected rather than treated as automatically compatible. A narrow early Saab wheel may be a good match for one radial and less ideal for another, even inside the same size family. If your car has been repainted, widened, or swapped to later wheels, confirm both diameter and width before fitting tires. Keeping the original wheels and choosing the correct tire is often the cleanest route, but it still deserves a careful measurement.

A 1958 Saab should be stored in a cool, dry, dark space away from direct sunlight, electric motors, welders, battery chargers, and other ozone-producing equipment. Keep the tires clean, maintain proper inflation, and move the car periodically so one section of the tread is not carrying the load for months at a time. Bias-ply tires such as a 5.20-15 can flat-spot more readily during long static storage, while both bias-ply and radial sidewalls can suffer from age cracking when exposed to ozone and heat.

For a car that sits through a season, many collectors either roll it slightly every few weeks or support it in a way that reduces prolonged loading. That approach is especially useful on a lightweight but narrow-tired car like a 1958 Saab, where long rests can still leave a noticeable impression in the casing. If the car is covered, use a breathable cover rather than trapping moisture around the tires. Good storage habits do more to preserve collector tires than low mileage alone.

Tire life on a 1958 Saab is usually judged more by age than by miles. A collector car can wear very little tread and still reach the point where the rubber, casing, and inner components deserve replacement because of age. A sensible rule is to begin close evaluation around five to seven years and to treat ten years as a point where replacement should be strongly considered regardless of appearance. The DOT date code on the tire sidewall is the reference point for age.

That age-based approach matters because vintage cars like a 1958 Saab often spend more time parked than driven, and parked tires can still deteriorate. Visual condition is important, but it should not be the only test. A tire that looks acceptable from a few feet away may still have hardened rubber, internal aging, or cracking beginning near the bead and sidewall. If the age is creeping up and you are planning tours or longer drives, it is wise to evaluate replacement before the season starts rather than after a problem appears.

Tires on a 1958 Saab should be inspected before every drive and more thoroughly before any extended outing. Look for sidewall cracking, cuts, bulges, unusual tread wear, and any sign that the tire is losing pressure between uses. On cars using tube-type tires, the valve stem and any signs of tube-related leakage deserve added attention. Even a lightly driven Saab can develop age-related issues that are not obvious until you examine the tires closely.

A quick pre-drive inspection is one of the simplest habits that pays off on an older car. Narrow vintage tires can hide problems if you only glance at the outer sidewall, so inspect both sides whenever practical and do not forget the spare. If the car has been sitting, check inflation before moving it any real distance because storage-related pressure loss is common. Regular inspections also help you catch suspension or alignment issues early, since odd wear patterns often show up at the tire first.

For a 1958 Saab 92 & 93, bias-ply construction is the era-correct starting point to think about when discussing original-type fitment. The listed 5.20-15 size reflects that older inch-based bias-ply tradition, while 145R15 represents a radial alternative available for the same model family. By the late 1950s, Saab was part of a European market that would soon become strongly associated with radial development, but the exact original fitment can still vary by market, wheel, and how a specific car was delivered.

If originality matters, begin with the 5.20-15 bias-ply format and then verify details against factory literature, marque references, or Saab club knowledge for your particular car. That is especially important with export-market cars and long-restored examples, where what is fitted today may reflect later owner preference rather than period-correct practice. For a driver rather than a judged restoration, the 145R15 radial remains a legitimate period-flavored alternative in the correct narrow 15-inch family. The right answer depends on whether you are restoring a moment in time or preparing a car to be used more often.

Correct tire fitment can matter a great deal when showing a 1958 Saab, especially in classes that reward factory-correct presentation. Judges and knowledgeable enthusiasts often notice three things quickly: the overall size, the construction type, and the sidewall appearance. A radial on a car judged for strict originality may be viewed differently from a bias-ply, and an eye-catching whitewall can also look out of place if the event expects a more factory-authentic Scandinavian presentation.

That does not mean every show follows the same standard. Some events focus on preservation or driving enjoyment, while others are far stricter about what is considered authentic. Before committing to a tire, decide whether your Saab is being built for touring, local display, or marque-judged competition. If authenticity is the goal, compare your intended tire against period photographs, owner literature, and Saab club guidance for your model and market. Tire fitment is one of the few restoration details that changes both appearance and driving behavior, so it deserves more thought than a simple size match.

The 1958 Saab 750 & 850 GT uses 155R15 in the available fitment range, and that size places the GT models in a distinct radial 15-inch category apart from the 92 and 93. Saab's reputation in this period was closely tied to advanced small-car engineering and a European market increasingly associated with radial development. Even so, exact original-delivery details can vary by destination market and by how a surviving GT has been restored over the decades.

For a GT owner, the safest restoration path is to treat 155R15 as the correct size family and then refine the choice by sidewall presentation and product type. Since the available 155R15 options are blackwalls, that look also aligns naturally with the sporting, understated personality most enthusiasts associate with these models. If you are aiming for judged authenticity, consult period Saab references and club expertise before finalizing a tire. A GT is more likely than a standard 92 or 93 to be scrutinized for details that support its sporting identity, and tire choice is part of that presentation.

1958 Saab tires can be suitable for highway driving when they are the correct size, properly fitted, in sound condition, and used within their construction and speed-rating limits. Among the listed radial options, some 145R15 products carry an S rating to 112 mph, while 155R15 products include T-rated versions to 118 mph and H-rated versions to 130 mph. Those figures are tire ceilings, not recommendations for how fast a 1958 Saab should be driven. The car's brakes, suspension, steering condition, and overall mechanical state are usually the more important limiting factors in normal highway use.

For real-world driving, the key is to think of the tire as one part of a complete vintage-car system. A healthy radial can give reassuring road manners, but it does not override the age or setup of the car itself. A bias-ply tire can also be roadworthy when properly chosen and maintained, though it will not feel the same as a radial at speed. Before a highway trip, verify tire age, inflation, and overall condition, then drive the Saab in a way that respects the capabilities of the entire vehicle rather than chasing the highest speed number printed on the tire.

Inflation pressure on a 1958 Saab should not be guessed from size alone. Where tire ratings are published, a 155R15 Firestone F560 carries a maximum load of 1045 pounds at 44 psi, and a 145R15 Firestone F560 carries a maximum load of 935 pounds at 44 psi. Those are tire capacity ratings, not universal running pressures for every 1958 Saab. The correct operating pressure for the car still belongs to the vehicle's factory guidance and the specific tire maker's recommendations for that product and application.

The practical rule is to start with the Saab owner's or service literature for factory pressure guidance, then confirm that recommendation against the tire manufacturer if you are using a reproduction or later-spec tire. Do not transfer a pressure figure from a 155R15 tire to a 145R15 tire, and do not assume a listed maximum pressure is the same thing as the best day-to-day setting. Pressure has a strong effect on wear, ride quality, and handling in a light vintage Saab. If you are changing construction type, pay attention to how the car responds once the tires are properly seated and heat-cycled.

Before taking a 1958 Saab on a longer drive, inspect every tire for cracking, cuts, bulges, uneven wear, and proper inflation. Check the spare as carefully as the four road tires, because a neglected spare is common on collector cars. If your chosen tire is tube-type, inspect the valve stems and make sure the wheel and tube setup are appropriate and holding pressure. A longer drive is also the right moment to confirm wheel fasteners, brakes, steering feel, and fluid levels as part of the same pre-trip routine.

A methodical walk-around is far more valuable than assuming low annual mileage means everything is ready. Tires on an older Saab often age out before they wear out, and a car that drives fine around town can still reveal problems when heat, speed, and distance increase. Pay attention to any vibration or pull in the first few miles, then stop and recheck if something feels off. On a small vintage Saab, the tire's condition and the car's mechanical condition are closely linked, so the best road-trip preparation treats them as one system.