1970 Simca Tire Fitment Guide

1970 Simca vehicles use four sizes: 145R13, 520-13, 155R13, and 560-13. The 1118 uses 145R13 and 520-13, while the 1204 uses those two shared sizes plus 155R13 and 560-13. All four sizes mount on 13-inch rims, so diameter stays consistent across the year even though section width and construction change by size.

The practical takeaway is that year and make alone are not enough if you own a 1204, because that model spans both narrow and wider options. Rim width should be checked against the tire you choose, especially if you are moving between shared and 1204-specific sizes. On products where rim-width guidance appears, 145R13 suits 4.00 to 5.00-inch rims, 155R13 suits 4.00 to 5.50-inch rims, 520-13 appears on 3.5-inch and 3.50 to 4.00-inch applications, and 560-13 appears on 3.50 to 4.50-inch applications depending on brand.

On a 1970 Simca, 520-13 is a numeric bias-ply size. The 5.20 portion is the nominal section width in inches, written without a decimal in the common vintage style, and the 13 identifies the wheel diameter in inches. Unlike a modern metric radial code, this format does not spell out an aspect ratio or include an R for radial construction.

That matters because 520-13 reads like a true period size for a 1970-era compact and carries the visual and handling character associated with bias-ply tires. If your Simca is being restored with originality in mind, this is the kind of sizing convention buyers expect to see. If you are comparing it to 145R13, the decision is less about wheel diameter and more about whether you want a vintage-format bias-ply tire or a radial with later road manners.

No. Both 1970 Simca models share 145R13 and 520-13, but only the 1204 also uses 155R13 and 560-13. That means the 1118 stays with the narrower shared radial and bias-ply fitments, while the 1204 opens the door to wider versions in both construction types.

If you are shopping for a 1970 Simca by year alone, that distinction can send you toward the wrong tire family. The 1118 is simpler because both of its sizes are shared across the range, but the 1204 requires one more step: confirm whether the car is running its shared-size setup or one of the wider model-specific options. Once the model is confirmed, the remaining choice is usually construction style and sidewall appearance rather than wheel diameter.

For a 1970 Simca 1118, both 520-13 and 145R13 are valid fitments, and the same is true for the 1204 before moving into its wider options. The difference is construction: 520-13 is a bias-ply tire in a vintage numeric format, while 145R13 is a radial in a Euro-metric style. Both fit a 13-inch rim diameter, so the real choice is about tire type and vehicle character rather than a change in wheel size.

Owners chasing a more era-correct look often gravitate toward 520-13, especially when a blackwall or narrow whitewall appearance matters to the finished presentation. Owners who want a radial tire for regular road use usually start with 145R13 instead. That does not automatically make one universally right and the other wrong; it means your intended use, restoration goals, and wheel-width compatibility should guide the decision.

1970 Simca tire choices span blackwall, narrow whitewall, and wide whitewall designs, depending on size. The radial sizes 145R13 and 155R13 are available in blackwall form. The bias-ply 520-13 appears in blackwall and narrow whitewall versions, while 560-13 appears in narrow whitewall and wide whitewall versions.

For a compact European car like a 1970 Simca, blackwall is the most natural visual fit if you are aiming for a restrained factory-style presentation. Whitewall options can still make sense when the goal is a customized look, a period accessory appearance, or a very specific restoration direction. The easiest way to narrow the choice is to decide first whether you want a stock European look or a stronger decorative sidewall statement, then match that preference to the correct size for your model.

Michelin, Firestone, Premium Sport, Dunlop, and BFGoodrich all have coverage for 1970 Simca fitments. In 145R13, the brands are Michelin and Firestone. In 520-13, the brands are Firestone and Premium Sport. In 155R13, the brands are Michelin and Dunlop. In 560-13, the brands are BFGoodrich and Firestone.

That spread gives Simca owners a useful mix of period-style bias-ply offerings and classic radial choices. Michelin is especially relevant to buyers who want a distinctly European radial character, while Firestone appears in both radial and bias-ply fitments across the range. The best way to use the brand mix is to narrow the car to the right size first, then compare sidewall appearance, construction type, and any load or speed marking differences within that size.

Rim-width guidance varies by size on 1970 Simca tires. 145R13 appears with a 4.00 to 5.00-inch rim-width range, while 155R13 appears with a 4.00 to 5.50-inch range. In the bias-ply group, 520-13 appears on 3.5-inch and 3.50 to 4.00-inch applications, and 560-13 appears on 3.50 to 4.00-inch and 4.00 to 4.50-inch applications depending on the tire.

That means wheel width becomes the key technical checkpoint once you already know the car uses a 13-inch rim diameter. A 1204 owner considering the wider 155R13 or 560-13 should verify the actual wheel before choosing a product, because not every 13-inch wheel is equally suited to every width range. Matching the tire to the wheel matters for proper section shape, bead seating, and overall appearance.

Inner-tube requirements vary by size and by product on 1970 Simca tires. The Michelin 145R13 and Michelin 155R13 products carry TL markings, which indicate tubeless construction. Other sizes do not use the same explicit tube notation across every product, so the safest reading is that tube use can vary depending on the exact tire and wheel combination rather than being treated as universal for the full range.

The important next step is to match the tire type to the wheel you are actually using. Original 13-inch steel wheels, especially on older collector cars, may have condition or design factors that influence whether a tube is advisable even when the tire itself is tubeless. Check the sidewall marking on the specific tire and inspect the wheel condition before final assembly so the setup matches both the product and the wheel.

All 1970 Simca sizes in this range use a 13-inch rim diameter, so original 13-inch wheels are compatible in diameter with 145R13, 520-13, 155R13, and 560-13. That shared diameter is helpful because it keeps the conversation centered on width and construction rather than a wheel-diameter change. It does not mean every original wheel is automatically ideal for every size, especially once the 1204’s wider options enter the picture.

A sound approach is to treat diameter as confirmed and then verify wheel width before making a final choice. The narrower shared sizes are generally the easiest path for broad compatibility, while 155R13 and 560-13 deserve a closer look at the actual wheel dimensions. If the car has been restored, modified, or fitted with replacement wheels at some point in its life, measure the wheel rather than assuming it remains to original specification.

A 1970 Simca should be stored on clean, properly inflated tires in a cool, dry, dark space away from direct sunlight, electric motors, welders, battery chargers, and other ozone-producing equipment. Bias-ply tires such as 520-13 and 560-13 can flat-spot more readily during long static storage, while any collector tire can suffer sidewall aging if exposed to heat and ultraviolet light over time.

For longer storage intervals, roll the car periodically or support it in a way that reduces constant load on one contact patch, while still following safe lifting practices. Keeping the car on a bare concrete floor without a barrier is less desirable than using a clean surface or tire cradles. Good storage habits preserve ride quality, protect the sidewalls, and help a lightly used Simca stay ready for occasional seasonal driving.

On a 1970 Simca, tire life should be judged more by age and condition than by miles traveled. Collector-car tires are commonly evaluated closely once they reach the five- to seven-year range, and many owners begin serious replacement consideration by around ten years regardless of remaining tread. The DOT date code on the tire sidewall is the starting point for understanding actual age.

A low-mileage Simca can still need new tires if the rubber has hardened, cracked, or spent years exposed to poor storage conditions. Bias-ply and radial tires both age out even when the tread looks usable, and an attractive sidewall is not a substitute for fresh rubber. Regular review of age, visible condition, and pressure retention is far more meaningful than trying to estimate lifespan from mileage alone.

Tires on a 1970 Simca deserve a quick inspection before every drive and a more deliberate inspection before any extended outing. Look for sidewall cracking, cuts, bulges, uneven wear, embedded debris, and pressure loss. On tube-type or possibly tube-equipped combinations, valve stem condition and signs of slow leakage deserve special attention as well.

Older compact cars often spend long stretches parked, which makes time-based inspection especially important. A Simca that looked fine at the last event may have developed pressure loss or fresh weather checking while sitting. Building a simple routine around pressure, sidewall condition, and spare-tire inspection reduces surprises and makes the car more enjoyable when it is time to take it back on the road.

For a 1970 Simca 1118, the relevant original-style fitments are the shared 520-13 bias-ply and 145R13 radial sizes used on that model. By 1970, European small cars could appear with either bias-ply or radial construction depending on market and specification, so both size paths matter when researching authenticity. No single original equipment brand should be assumed without checking market-specific references for the exact car.

If your goal is restoration accuracy, start by confirming which of the two shared sizes belongs with your car’s market, trim presentation, and restoration standard. The size itself is only part of the picture, because sidewall treatment and construction type can influence how correct the finished car looks to knowledgeable enthusiasts. Marque clubs, period sales literature, and long-time Simca specialists remain the best references for final originality calls.

Correct tire fitment absolutely matters when showing a 1970 Simca, especially at events that judge authenticity and period presentation. Judges and experienced enthusiasts often notice whether the car carries the right size family, the right construction style for the restoration goal, and a sidewall appearance that matches the era and market character. A blackwall radial and a whitewall bias-ply can create very different impressions even when both physically fit a 13-inch wheel.

For a concours-minded car, fitment should be treated as part of the restoration rather than a final accessory decision. A 1204 wearing one of its wider model-specific sizes may be correct in one context and out of place in another, depending on the exact car being recreated. Event standards vary, so it is wise to compare your planned tire to period photos, judging guidelines, and Simca-specific club knowledge before finalizing the look.

In 145R13 for a 1970 Simca, Michelin XAS and Firestone F560 Radial are both blackwall radial options, but their visible specifications are not identical. The Michelin uses a 145HR13 74H TL marking and weighs 18 pounds, while the Firestone 145R13 carries a 4.00 to 5.00-inch rim-width range, a maximum load of 825 pounds at 44 psi, and weighs 12.7 pounds. Both remain within the same basic size family and 13-inch diameter.

That makes the comparison less about whether one fits the year and more about what details matter most to you within the same radial category. Some owners focus on period European character and specific sidewall markings, while others care more about matching wheel width guidance or comparing load information where it is stated. Looking closely at the exact sidewall wording and wheel compatibility helps separate two tires that sit in the same nominal size.

1970 Simca tires can be appropriate for highway use when they are fresh, correctly fitted, and used within their stated speed capability. The radial sizes 145R13 and 155R13 include H-rated examples, which carry a 130 mph ceiling. The bias-ply sizes 520-13 and 560-13 do not show the same kind of speed-letter consistency in their markings here, so highway use with those sizes should be approached with the normal expectations of a vintage bias-ply tire on an older compact car.

In real-world driving, the tire is only one part of the equation on a 1970 Simca. Braking feel, suspension condition, steering play, and the general pace of an older small car often matter more than the tire’s theoretical upper speed ceiling at normal American highway speeds. Safe use comes from treating the whole car as a system and keeping speeds appropriate to its age, condition, and tire type.

Inflation pressure on a 1970 Simca should be set by the vehicle’s factory guidance first and then checked against the tire’s own rated pressure information. Some of these sizes include explicit load-and-pressure figures: 145R13 reaches 825 pounds at 44 psi on one product, 520-13 appears at 770 pounds at 32 psi and up to 1100 pounds at 60 psi depending on the tire, and 560-13 reaches 850 pounds at 30 psi on multiple products. Those figures are product ratings, not universal vehicle settings.

That distinction matters because maximum pressure is not the same thing as the correct operating pressure for your Simca. Tire size, construction, vehicle loading, and the manufacturer’s intended ride and handling balance all affect the final number. Use the car’s manual or factory placard as the baseline, then confirm that your chosen reproduction or replacement tire is operating appropriately within its own published limits.

Before a longer drive in a 1970 Simca, inspect all four tires and the spare for cracking, cuts, bulges, irregular wear, and proper inflation. Pay close attention to valve stems, and if the car uses tube-type or tube-equipped assemblies, look for signs of leakage or age around the stem area. Wheel fastener security, tread condition, and any evidence of contact or rubbing should also be part of the pre-drive routine.

A longer trip in an older Simca should also include the broader checks that make vintage cars dependable: brakes, lights, fluids, cooling, and steering condition. The tires are where the car meets the road, but they work in partnership with every other mechanical system. A careful inspection before departure is especially worthwhile on a compact collector car that may spend much of its life on short, occasional drives instead of daily use.