In 1966, Simca represented the practical, compact side of the European car market, and the rear-engine Simca 1000 gave buyers a small sedan with distinctly Continental proportions and tire sizing that can look unfamiliar to American collectors today. For a year-make page like 1966 Simca, the key is less about sorting through a broad model range and more about understanding why one model could appear with four different sizes across 12-inch and 13-inch fitments, split between bias-ply and radial construction. That makes the first step simple but important: confirm your wheel diameter first, then decide whether you want a period-style bias-ply tire or a radial driving experience.
Which Tire Size Is Right for Your 1966 Simca
Four tire sizes are associated with 1966 Simca, and all four apply to the Simca 1000 rather than being divided across multiple models. The real decision starts with wheel diameter, since these sizes span both 12-inch and 13-inch rims, and then moves to construction choice between bias-ply and radial depending on how you want the car to look and drive. Understanding that distinction before choosing a product saves time and helps match the tire to the car correctly.
Year(s): 1966|Fit(s): 1000|Construction: Radial|Rim: 13 in
145R13 is a metric radial size with a 145-millimeter nominal section width and a 13-inch rim diameter; without a stated aspect ratio, this format is conventionally treated as an 80-series radial. Michelin and Firestone offer this size in blackwall form, and the available products are tubeless, with Michelin carrying an H speed rating for 130 mph while Firestone uses a standard 145R13 marking. This is one of the 13-inch options specific to the Simca 1000 and suits owners who want a more modern radial construction while staying within an era-appropriate small-car size.
Year(s): 1966|Fit(s): 1000|Construction: Bias Ply|Rim: 13-in rim
5.50-13 is a numeric bias-ply size in which 5.50 refers to the nominal section width in inches and 13 is the rim diameter. Bias-ply construction gives this size its period character, and product-specific details such as brand, sidewall treatment, tube use, and speed marking should be checked on the individual tire before ordering. This is the bias-ply 13-inch choice for the Simca 1000 and is the natural direction for a restoration that aims to preserve a distinctly mid-1960s look and feel.
Year(s): 1966|Fit(s): 1000|Construction: Radial|Rim: 12-in rim
155R12 is a metric radial size with a 155-millimeter nominal section width and a 12-inch rim diameter; as with other Euro-metric sizes written this way, the unstated profile is conventionally understood as an 80-series radial. Radial construction defines the practical character of this size, and individual product details such as brand, sidewall style, tube status, and speed rating should be confirmed before making a final choice. This 12-inch radial size is specific to Simca 1000 applications using the smaller wheel diameter, so it is not interchangeable with the 13-inch choices without matching wheels.
Year(s): 1966|Fit(s): 1000|Construction: Bias Ply|Rim: 12-in rim
5.60-12 is a numeric bias-ply size, with 5.60 indicating nominal section width in inches and 12 indicating the wheel diameter. Its traditional bias-ply construction is the defining feature of the size, and product-level details such as sidewall appearance, tube fitment, and speed marking should be verified on the exact tire chosen. This is the 12-inch period-style option for the Simca 1000 and makes the most sense when the car retains its smaller-diameter wheels and the owner wants an authentic vintage presentation.
One model is covered for 1966 Simca: the Simca 1000. Because every tire size for the year belongs to that single model, the important fitment question is not choosing between different Simca model lines but confirming whether your car is running 12-inch or 13-inch wheels and whether you want bias-ply or radial construction. Select the model below to continue into model-specific fitment history and tire options.
1966 Simca 1000
The 1966 Simca 1000 was a compact French sedan known for its rear-engine layout, tidy proportions, and straightforward mechanical character, making it appealing today to collectors who enjoy small European cars with a distinctly 1960s feel. Its tire choices span both 12-inch and 13-inch wheels, so the car's current wheel setup matters just as much as the size code on the sidewall when narrowing down the correct fitment.
Two products are available across four tire sizes for 1966 Simca vehicles. In 145R13, Michelin and Firestone offer radial blackwall choices; confirm your exact size, wheel diameter, and preferred construction before selecting a tire.
These FAQs cover how 1966 Simca tire sizes differ between 12-inch and 13-inch fitments, when bias-ply or radial construction makes more sense, and what to check for collector-car storage, setup, and road use.
Size Basics & Fitment
What tire sizes fit 1966 Simca vehicles?
1966 Simca fitment centers on the Simca 1000, which uses four sizes: 145R13, 5.50-13, 155R12, and 5.60-12. The 145R13 and 5.50-13 mount on 13-inch wheels, while the 155R12 and 5.60-12 mount on 12-inch wheels. Rim width guidance is available within the 145R13 products at 4.00 to 5.00 inches, while the other sizes should be matched to the actual wheel and the specific tire chosen.
That means a 1966 Simca owner should not assume every Simca 1000 uses the same wheel diameter just because the year and model match. Start by reading the sidewall on the existing tire or measuring the wheel diameter, then choose between the radial and bias-ply size that corresponds to that wheel. Once wheel diameter is confirmed, the remaining choice becomes one of driving character and restoration style rather than basic fitment.
What does 145R13 mean on a 1966 Simca tire?
On a 1966 Simca, 145R13 is a Euro-metric radial size. The 145 refers to a nominal section width of 145 millimeters, the R indicates radial construction, and the 13 identifies a 13-inch wheel. When a metric size is written this way without an aspect ratio, it is conventionally understood as an 80-series radial format.
For a Simca 1000 owner, that code matters because it points to both the construction type and the wheel diameter in a single marking. A 145R13 radial will not replace a 12-inch tire simply because both came on the same year and model family. It is also a modern-feeling alternative to a 13-inch bias-ply size, so it appeals to owners who want to stay close to the original proportions while gaining radial behavior.
What do 5.50-13 and 5.60-12 mean on 1966 Simca tires?
On 1966 Simca applications, 5.50-13 and 5.60-12 are numeric bias-ply sizes. In that older sizing system, the first number is the nominal section width in inches and the second number is the wheel diameter in inches, so 5.50-13 fits a 13-inch wheel and 5.60-12 fits a 12-inch wheel. Because there is no R in the code, these are bias-ply tires rather than radials.
Those numeric sizes are familiar territory for restorers because they reflect the kind of sizing language common on small imported cars of the era. For a 1966 Simca owner, the practical takeaway is simple: do not compare the 5.50 and 5.60 numbers alone. The wheel diameter after the dash is the first thing to verify, and once that matches your wheel, you can decide whether a bias-ply tire fits the look and driving character you want.
Buying the Right Tire
Should I choose the 145R13 or the 5.50-13 for my 1966 Simca?
A 1966 Simca running 13-inch wheels can point you toward either 145R13 radial or 5.50-13 bias-ply, but they serve different priorities. The 145R13 uses radial construction and is available in blackwall form from Michelin and Firestone, while 5.50-13 is a traditional numeric bias-ply size. The radial route generally suits owners who want more familiar modern road manners, while the bias-ply route better preserves a mid-1960s presentation.
The right choice depends on how your Simca 1000 is used. A car built around authenticity, period-correct stance, and era feel will usually lean toward the bias-ply option in the correct wheel diameter. A car that sees more regular driving often benefits from staying with the proper 13-inch wheel but moving to radial construction. Confirm your wheel diameter first, because neither of these 13-inch sizes is a substitute for the 12-inch fitments.
What sidewall styles are available for 1966 Simca tires?
For 1966 Simca fitment in 145R13, the available products use a blackwall sidewall style. That appearance is appropriate to the modest, compact European character of a Simca 1000 and aligns well with the understated look many restorers want on a small French sedan. Sidewall presentation on the other sizes should be checked on the exact tire selected, especially if visual accuracy is a major part of the project.
Sidewall style matters because it changes the look of the car almost as much as the wheel itself. On a 1966 Simca, a blackwall usually looks natural and era-appropriate, especially on a driver-grade or tastefully restored car. If you are building toward marque-level originality, compare the sidewall treatment on the tire you choose against period photos, surviving original cars, and club guidance so the tire complements the car rather than distracting from it.
What brands make tires for 1966 Simca vehicles?
Michelin and Firestone both cover 1966 Simca in 145R13 radial form. Michelin's presence is especially fitting for a French-market-oriented car like the Simca 1000, while Firestone gives owners another established name in a small-car radial size. Brand choice on the remaining Simca sizes depends on the exact size and product selected.
For most buyers, the better way to use brand information is to narrow the fitment first and then compare the construction and sidewall details within that size. A 1966 Simca owner with 13-inch wheels can compare Michelin and Firestone directly in 145R13, but a car on 12-inch wheels needs the correct diameter confirmed before brand becomes the deciding factor. The strongest match is always the brand and product that aligns with your wheel size and the way the car will be used.
Fitting & Setup
What rim width do 1966 Simca tires require?
Rim width guidance for 1966 Simca is available within the 145R13 radial offerings, where the tire fits rims from 4.00 to 5.00 inches wide. That range applies specifically to 145R13 rather than to every Simca size from the year. The 12-inch and bias-ply alternatives should be matched to the actual wheel and the specifications of the exact tire you intend to run.
That makes wheel verification an important setup step on any Simca 1000, especially if the car has changed hands or been restored over the years. A 13-inch wheel should still be checked for width before committing to a 145R13, and a 12-inch wheel should not be assumed to accept a 13-inch tire just because both were used on the same model line. Measuring the wheel now prevents avoidable fitment frustration later.
Do 1966 Simca tires require inner tubes?
1966 Simca tube requirements depend on the exact size and product. In 145R13, the available tires are tubeless, including one marked TL. Tube status for the other Simca sizes should be confirmed on the individual tire, because older-style bias-ply fitments can differ by product and by wheel condition.
A tubeless radial on a sound wheel is a different setup conversation than a vintage-style bias-ply on an older rim. Simca owners should treat tube fitment as part of the wheel-and-tire package rather than as an afterthought. If the car still uses original steel wheels, inspect the bead seats and valve area carefully, and match the tire type to a wheel condition that supports safe sealing and dependable pressure retention.
Can the original 1966 Simca wheels be used with all tire sizes?
Original 1966 Simca wheels can only be used with the tire sizes that match their diameter. A 13-inch Simca wheel can accept the 145R13 or 5.50-13 sizes, while a 12-inch wheel belongs with 155R12 or 5.60-12. Wheel diameter is the hard limit here, and it is more important than the fact that all four sizes were associated with the same model year.
That means the original wheel set on your particular Simca 1000 determines which branch of fitment you should follow. If the car has already been converted from 12-inch to 13-inch wheels or vice versa, choose tires around the wheels currently on the car rather than around a general year-make assumption. After diameter is confirmed, check wheel width and overall condition so the final tire choice supports both appearance and proper mounting.
Maintenance, Storage & Longevity
How should I store a 1966 Simca when the tires are fitted?
A 1966 Simca should be stored clean, dry, and out of direct sunlight, with the tires kept away from ozone-producing sources such as electric motors, battery chargers, and some shop equipment. Bias-ply tires tend to flat-spot more readily during long static storage, while both bias-ply and radial sidewalls can age prematurely if they sit under UV exposure or in damp conditions. Maintaining proper inflation through the storage period also helps the tires hold their shape.
For a Simca 1000 that sits for weeks or months at a time, periodic movement is helpful, and long-term storage on stands can reduce load concentration if done correctly. The goal is not just preserving tread, but preserving sidewall integrity and casing shape on a small, lightweight collector car that may not wear tires out by mileage. Good storage habits often matter more than annual miles driven when it comes to preserving vintage-sized tires.
How long do tires on a 1966 Simca typically last?
On a 1966 Simca, tire life is usually judged by age, condition, and storage history more than by mileage. Collector tires should be evaluated closely once they are about five to seven years old, and replacement becomes a serious consideration as they approach ten years, even if tread depth still looks acceptable. The DOT date code on the tire helps establish age, and the sidewall condition often tells the real story.
That age-based approach matters because many Simca 1000s are hobby cars that spend far more time parked than driven. A tire that looks usable from ten feet away may still have internal aging or sidewall deterioration that makes it a poor candidate for continued road use. Checking age before each season begins is a smart routine, especially if the car is being recommissioned after a long rest or a multi-year restoration.
How often should tires on a 1966 Simca be inspected?
Tires on a 1966 Simca should be inspected before every drive and again before any extended outing. Look for sidewall cracking, tread separation, bulges, cuts, uneven wear, and signs that the tire is not holding pressure consistently. If your Simca uses a tube-type setup on one of the vintage sizes, valve stems and tube-related pressure loss deserve especially close attention.
Frequent inspection is important because a lightly driven collector car can hide tire problems that would become obvious on a daily driver. A Simca 1000 may spend weeks in the garage between runs, and that stop-start use pattern makes visual checks more valuable than relying on habit. Catching a crack, bruise, or pressure issue at the garage door is far better than discovering it after the car is already settled into highway traffic.
Restoration & Authenticity
What tires were originally fitted to the 1966 Simca 1000?
A 1966 Simca 1000 would have been associated with period-correct sizing in both numeric bias-ply and early metric radial forms, depending on market expectations and the wheel package on the car. The year sits in an era when bias-ply was still common, but European small cars were also closely tied to the growing use of radial construction. That makes both the wheel diameter and the style of restoration important when judging what feels most authentic for a particular car.
For a factory-authentic restoration, use the car's wheel diameter and surviving evidence from the vehicle itself as the first guide, then compare that against period literature and Simca club knowledge. It is wise to confirm market-specific details through marque specialists, since imported European cars sometimes differed by destination market or by how they were equipped when new. A tire that is era-correct in size and construction will usually look more convincing than one chosen only by modern convenience.
Does correct tire fitment matter for showing a 1966 Simca?
Correct tire fitment does matter when showing a 1966 Simca, especially if the event values originality or preservation. Judges and knowledgeable enthusiasts often notice whether the tire size matches the wheel diameter properly, whether the construction looks appropriate to the era, and whether the sidewall style suits a modest mid-1960s European sedan. A radial on the right wheel may be acceptable for a driver-class presentation, but it is a different statement from a period-style bias-ply restoration.
That does not mean every Simca 1000 must wear the same tire to be respected, but it does mean the tire choice should match the goal of the car. A touring-oriented car can justify a radial if the owner values road use, while a concours-minded car usually benefits from the more historically aligned construction and appearance. Event standards vary, so the best final check comes from the rulebook and the Simca community connected to that style of judging.
What is the difference between Michelin XAS-FF and Firestone F560 Radial tires for the 1966 Simca?
For a 1966 Simca in 145R13, Michelin XAS-FF and Firestone F560 Radial are both blackwall radials, but they differ in several specifics. The Michelin carries a 145HR13 74H TL marking, which includes an H speed rating up to 130 mph, and it weighs 18 pounds. The Firestone uses a 145R13 size marking, carries a maximum load figure of 825 pounds at 44 psi, fits 4.00- to 5.00-inch rims, and weighs 12.7 pounds.
Those differences matter most when a buyer is comparing setup priorities within the same wheel diameter. One Simca owner may focus on the Michelin's speed-marked European character, while another may appreciate the Firestone's clearly stated load-and-pressure information and rim-width guidance. Neither one changes the fact that the car still needs the 13-inch fitment confirmed first, but once that is settled, these product details help narrow the choice more intelligently.
Safety & Road Use
Are 1966 Simca tires safe for highway driving?
1966 Simca tires can be appropriate for highway driving when the correct size is mounted on the correct wheel, the tire is in sound condition, and the product's construction and speed capability match the way the car will be used. In 145R13, one available tire carries an H speed rating with a 130 mph ceiling. In real-world use, a mid-1960s Simca 1000 is usually limited more by the condition of its brakes, suspension, steering, and overall age than by the theoretical top-end ceiling printed on a modern reproduction tire.
Highway safety in a vintage Simca starts with preparation rather than assuming any old tire in the right diameter is enough. Check inflation, inspect for age cracks and casing damage, and be realistic about how a lightweight rear-engine 1960s compact behaves in modern traffic. A healthy tire matched to the car's wheel is only one part of the equation, but it is a critical one, especially if the car has spent long stretches off the road.
What inflation pressure should I use for 1966 Simca tires?
Inflation pressure on a 1966 Simca should be tied to the exact tire you are using rather than borrowed from another size on the same model. In 145R13, one available radial carries a maximum load of 825 pounds at 44 psi, but that figure is the tire's rated load-and-pressure point, not a universal operating recommendation for every Simca fitment. Factory running pressures belong to the vehicle literature, while the tire manufacturer defines the tire's own limits.
The smart approach is to start with the original Simca guidance for the wheel and loading conditions your car uses, then confirm that your chosen tire is being operated within its own rated parameters. Do not transfer a 145R13 pressure figure onto 155R12, 5.50-13, or 5.60-12 simply because all four sizes relate to a 1966 Simca 1000. Matching pressure practice to the exact tire helps preserve wear, handling balance, and casing health.
What should I check before taking a 1966 Simca on a longer drive?
Before a longer drive in a 1966 Simca, inspect every tire for cracking, cuts, bulges, irregular tread wear, and proper cold inflation, and make sure the spare is usable as well. A small imported collector car also benefits from a close look at valve stems, wheel condition, and pressure retention over time, particularly if the setup may involve older-style tube-type fitments. Tire age should be part of that pre-drive check, not something discovered after the trip has already started.
A longer outing is also the right moment to think beyond the tires themselves. The Simca 1000's age makes a broader mechanical check worthwhile, including brakes, steering response, cooling, lights, and fluid levels. Tires are simply the contact patch that reveal whether the whole car is ready for the road. If the car has been stored for an extended period, a careful shakedown close to home is a better first step than heading straight into sustained highway driving.
