1968 Simca Tire Fitment Guide

1968 Simca fitment centers on the Simca 1000, which uses four size designations: 145R13, 5.50-13, 155R12, and 5.60-12. The 145R13 and 5.50-13 sizes mount on 13-inch wheels, while 155R12 and 5.60-12 mount on 12-inch wheels. Radial and bias-ply versions both appear within the year, so the correct choice depends on the wheel diameter already on the car and the type of tire construction you want to run.

That means year and make alone are not enough to choose a tire for a 1968 Simca. Start by checking the wheel diameter on the car, then confirm whether you want to stay with a period-style bias-ply setup or move to a radial size where available. On 145R13, radial fitment works with a 13-inch rim and products cover a 4.00 to 5.00 inch rim-width range, which gives a useful reference point when verifying the wheel before ordering.

On a 1968 Simca, 145R13 is a Euro-metric radial size. The 145 refers to the tire's nominal section width in millimeters, the R identifies radial construction, and the 13 is the wheel diameter in inches. Because no aspect ratio is printed, this style of size is conventionally treated as an 80-series metric radial rather than a modern low-profile tire.

For a Simca 1000 owner, 145R13 is the 13-inch radial route. It keeps the car in an appropriately narrow European size family while giving the driving feel associated with radial construction. If your wheels are 13-inch and your goal is road use with a more modern response than a bias-ply tire typically gives, this is the size code many buyers will recognize most easily.

On a 1968 Simca, 5.50-13 is a traditional numeric bias-ply size. The 5.50 designates the nominal section width in inches, and the 13 is the wheel diameter in inches. Unlike a metric radial size, it does not use millimeters or an R in the code, which is one reason these older size markings can look unfamiliar to modern buyers.

That size matters because it points to a different type of setup than 145R13, even though both fit a 13-inch wheel. A Simca 1000 running 5.50-13 is typically following a more period-correct visual and construction path. If authenticity, steering feel from the era, and restoration character matter more than a radial-style driving experience, this numeric size is the one to investigate first.

For a 1968 Simca on 13-inch wheels, the difference between 145R13 and 5.50-13 is mainly construction and character rather than wheel diameter. The 145R13 is a radial metric size, while the 5.50-13 is a numeric bias-ply size. Both belong to the Simca 1000's 13-inch fitment family, but they speak to different ownership goals.

Choose 5.50-13 if your priority is an original-era look and the kind of period driving character a bias-ply tire brings. Choose 145R13 if your car already uses that radial size or if you want a more modern-feeling road setup while staying within a narrow, appropriate size range. The key is to confirm that the car is on 13-inch wheels first, because neither of these is interchangeable with the 12-inch options.

Blackwall styling is available in 145R13 for 1968 Simca applications, including both Michelin and Firestone radial choices in that size. That look is very much in character for a European compact sedan from the late 1960s, where narrow blackwall tires are often the most visually natural choice. Sidewall appearance can still vary by exact tire line, even when the overall style remains blackwall.

For a Simca 1000, sidewall style is about visual correctness as much as fitment. A plain black sidewall tends to suit the clean, understated look these cars wore when new, especially compared with styles more associated with American domestic cars of the same period. If presentation matters, compare sidewall photos and overall profile carefully so the tire complements the car's scale instead of overpowering it.

Michelin and Firestone both cover 1968 Simca fitment in 145R13. Michelin appears in the XAS-FF line, while Firestone offers the F560 Radial in the same size. Both are radial blackwall choices for the Simca 1000's 13-inch fitment family, giving buyers two distinct brand directions within one common size.

Brand choice can matter for the kind of period flavor you want as much as for the basic size itself. Michelin feels especially at home on a French car because of its longstanding place in European motoring, while Firestone offers another familiar collector-tire name in the same fitment. After narrowing the correct size for your Simca 1000, compare brand, tube marking, speed symbol, and wheel-width compatibility before making the final call.

Rim-width guidance is available for 145R13 on 1968 Simca applications, where that radial size fits a 4.00 to 5.00 inch rim-width range on a 13-inch wheel. That is a useful benchmark for the Simca 1000's 13-inch radial fitment. The other sizes still need to be matched to the actual wheel on the car rather than assumed from year alone.

When checking wheels, confirm both diameter and width before choosing a tire. Diameter tells you whether the car is in the 12-inch or 13-inch family, while width helps determine whether a specific product is being mounted within its intended range. On a small European sedan like the Simca 1000, that step matters because a narrow original wheel can limit which reproductions are the most appropriate match.

Inner-tube requirements on 1968 Simca tires depend on the exact product and size. In 145R13, tube status varies by product: one Michelin tire is marked TL for tubeless use, while the Firestone example does not carry a tube marking here. Bias-ply sizes and the 12-inch sizes should be checked by the specific tire's sidewall marking and the wheel type being used.

That matters because tire construction alone does not answer the tube question. A buyer should confirm the tire's own marking and also make sure the wheel itself is suitable for tubeless use if going that route. If the car still wears original-style wheels, many owners take extra care here and verify compatibility before mounting rather than assuming every radial or every reproduction tire follows the same tube practice.

A 1968 Simca should be stored clean, dry, and out of direct sunlight, with the tires kept away from electric motors, battery chargers, furnaces, and other ozone-producing equipment. Correct inflation during storage helps the carcass hold its shape, and moving the car periodically can reduce flat-spotting. Bias-ply tires are generally more prone to temporary flat spots during long static periods than radials.

For a Simca 1000 that only comes out occasionally, thoughtful storage has a real effect on how the car feels when it returns to the road. If the car will sit for an extended season, many collectors either roll it a short distance from time to time or support it in a way that reduces constant load on one contact patch. A breathable car cover and a stable indoor environment help the tires as much as the bodywork.

Tires on a 1968 Simca should be judged more by age and condition than by mileage, since collector cars often see limited annual use. A sensible rule is to inspect closely once a tire reaches the five- to seven-year range and to treat around ten years as a point where replacement deserves serious consideration, even if tread depth still looks good. The DOT date code helps establish the tire's age.

That approach matters on a Simca 1000 because a car can look ready for a drive while the rubber has quietly aged out. Sidewall cracking, persistent air loss, hardening, vibration, or visible carcass distortion are all stronger warning signs than simple tread wear on a lightly used classic. If the age is borderline and you plan to do longer road miles, replacement is usually a wiser decision than trying to stretch another season.

Tires on a 1968 Simca should be inspected before every drive, and again more thoroughly before any extended outing. Check inflation, tread condition, sidewall cracking, cuts, bulges, and signs that the tire has begun to separate internally or lose its shape. If your setup uses tubes, valve stems and slow leaks deserve extra attention as part of the same routine.

A small, lightly built car like the Simca 1000 can be very sensitive to tire condition, especially after sitting. Catching a pressure loss or sidewall issue in the garage is far better than discovering it at highway speed or far from home. Make the spare part of the inspection too, because on many older cars the spare is forgotten until the day it is suddenly needed.

A 1968 Simca 1000 would have been associated with narrow European-style tires, and bias-ply construction was still a familiar original-era choice for small cars of this period even as radial adoption was becoming increasingly common in Europe. The size family for 1968 Simca includes both bias-ply and radial designations in 12-inch and 13-inch forms, which is consistent with the transitional character of the late 1960s.

For a restoration, the most accurate answer can depend on market, wheel package, and how the particular car was delivered when new. That is why many owners use the size family here as a starting point, then verify against factory literature, surviving examples, or a Simca marque specialist before finalizing a concours-level tire choice. Brand should not be assumed unless the car's own history or period literature supports it.

Correct tire fitment absolutely matters when showing a 1968 Simca, especially in preservation or originality-focused judging. Size, construction type, and sidewall appearance all influence whether the car looks true to its era. A modern-looking radial size on a car judged for factory-style authenticity, or a sidewall treatment that feels out of character for a late-1960s French sedan, can stand out immediately.

For many owners, that means deciding early whether the car is being restored to strict show standards or prepared as a tasteful driver. If it is a judged car, match the size family and construction to the car's intended presentation and confirm event-specific expectations with the relevant club or judging body. If it is a road car first, authenticity still matters, but usability may reasonably carry more weight.

For a 1968 Simca in 145R13, Michelin XAS-FF and Firestone F560 Radial are both radial blackwall choices, but their details are not identical. The Michelin carries a 145HR13 74H TL marking, which includes an H speed symbol with a 130 mph ceiling and a tubeless designation. The Firestone example in the same size shows a 4.00 to 5.00 inch rim-width range, a maximum load of 825 pounds at 44 psi, and a lower listed weight than the Michelin.

Those differences make this comparison more about matching the tire to your priorities than about declaring one universally right. Some owners will focus on the Michelin's period-European character and explicit speed marking, while others may care more about the Firestone's published wheel-width and load information. Either way, the important step is to verify the car's 13-inch wheels, then compare the exact tire markings and specifications that matter most to your use.

1968 Simca tires can be suitable for highway driving when the size, condition, inflation, and construction are all appropriate to the car. In 145R13, one available radial carries an H speed symbol, which corresponds to a 130 mph ceiling, while another 145R13 product does not present a speed symbol here. That means speed capability can vary even within the same size and should be confirmed on the specific tire you plan to run.

In real use, the safe highway limit of a Simca 1000 is rarely just a tire question. The condition of the brakes, steering, wheel bearings, suspension, and the general realities of a late-1960s economy car matter at least as much as the tire's printed rating. A sound car on properly matched, properly inflated tires can be enjoyable on modern roads, but every part of the package should be treated as age-sensitive.

Inflation pressure for 1968 Simca tires should follow the vehicle's factory recommendation for the specific wheel and size combination, then be checked against the tire manufacturer's own rating information. In 145R13, one Firestone radial carries a maximum load of 825 pounds at 44 psi, but that figure is the tire's rated maximum reference, not an across-the-board operating pressure for every 1968 Simca tire or every 145R13 product.

The practical takeaway is to avoid borrowing a pressure number from one size and applying it to the others. A 12-inch bias-ply setup and a 13-inch radial setup should not be treated as interchangeable simply because they fit the same model family. Start with the vehicle recommendation, confirm the exact tire marking, and make final pressure decisions only after verifying the size, construction, and intended use of the car.

Before a longer drive in a 1968 Simca, inspect each tire for cracking, cuts, bulges, uneven wear, punctures, and proper inflation, and make sure the spare is serviceable as well. Pay attention to valve stems and slow leaks, especially if your chosen tire and wheel setup involves tubes. On an older rear-engined compact, a careful visual check can catch problems that may not be obvious during short local use.

Tires are only one part of the pre-trip routine, but they are one of the most time-sensitive. After that inspection, it makes sense to look over wheel fasteners, brakes, steering feel, fluid levels, and lights before asking the car to cover more distance than usual. A 1968 Simca 1000 can be a rewarding road car when prepared properly, and a few extra minutes in the garage often prevent the kind of issues that spoil an otherwise enjoyable drive.