1968 Austin Tire Fitment Guide

1968 Austin vehicles use nine sizes across six models. The Austin 1100 uses 145R12 or 5.50-12, the Austin 1800 uses 175R13 or 650-13, the Austin 850 uses 145R10 or 5.20-10, the Austin A 40 uses 145R13 or 520-13, the Austin America uses 145R12 or 5.95-12, and the Austin Mini Cooper uses 145R10 or 5.20-10. Rim diameters vary by model family, with 10-, 12-, and 13-inch applications across the range.

That means year and make alone are not enough to choose correctly. Start by identifying the exact model, then confirm whether you want the radial size or the bias-ply size that belongs to that model. Rim width guidance also changes by size where available, so once the correct size is known, compare your wheel against the specific tire's approved range before making a final selection.

On a 1968 Austin, 145R10 is a metric radial size. The 145 is the nominal section width in millimeters, the R indicates radial construction, and the 10 is the wheel diameter in inches. Because no aspect ratio is printed, it is conventionally treated as an 80-series metric radial. Austin used this size on the 1968 Austin 850 and 1968 Austin Mini Cooper.

That code matters because it tells you this is the radial option for Austin's smallest 10-inch-wheel cars, not a universal size for the rest of the 1968 range. If your car is an 850 or Mini Cooper and still has its 10-inch wheels, 145R10 is the radial path to compare against 5.20-10. Confirm the actual wheel diameter before ordering, especially on cars that may have been modified over the years.

On a 1968 Austin, 650-13 is a numeric bias-ply size. The 6.50 refers to nominal section width in inches, and the 13 refers to rim diameter in inches. Unlike a metric radial code, there is no R in the size because this format belongs to the older bias-ply convention. Austin used 650-13 on the 1968 Austin 1800.

For a buyer, that means 650-13 is the period-style bias-ply choice for the 1800 rather than a substitute for the 10-inch or 12-inch Austin applications. It also opens sidewall appearance choices, since this size comes in both narrow and wide whitewall treatments. If your goal is restoration accuracy or a distinctly period visual profile on an 1800, this is the size to compare first.

For a 1968 Austin 1100, the choice between 145R12 and 5.50-12 is mainly a choice between radial and bias-ply construction on the same 12-inch wheel diameter. The 145R12 is the metric radial option, while 5.50-12 is the numeric bias-ply size. A similar radial-versus-bias decision also appears elsewhere in the 1968 Austin range, including the America, 850, Mini Cooper, A 40, and 1800 in their own model-specific sizes.

Owners focused on restoration presentation often lean toward the bias-ply size that matches the era, while owners who expect more routine road use often start with the radial equivalent for that model. The key is not to mix model families or wheel diameters in the process. Confirm the exact model first, then compare the correct radial and bias-ply pair that belongs to that car rather than crossing over to another Austin size.

1968 Austin tire choices include blackwall, narrow whitewall, and wide whitewall sidewall styles depending on size. The radial metric sizes with products here are blackwall only, including 145R12, 145R10, and 145R13. Among bias-ply options with products, 650-13 comes in narrow and wide whitewall styles, while 520-13 appears in blackwall and narrow whitewall form.

That makes sidewall choice partly a model question and partly a styling question. A compact British saloon or sporting small car often looks most natural on a blackwall radial or blackwall bias-ply, while whitewall bias-ply options can suit an owner pursuing a more stylized period presentation. If show authenticity matters, compare your intended sidewall look with period photos, marque references, and the way your specific Austin was originally delivered.

1968 Austin tire coverage includes Michelin, Coker Classic, US Royal, Firestone, Kings, Camac, Dunlop, and Premium Sport. Michelin appears in 145R12 and 145R13 radial applications, Firestone appears in 145R10, 145R13, and 520-13, Coker Classic and US Royal cover 650-13 bias-ply fitments, and Premium Sport appears in 520-13. Kings, Camac, and Dunlop add additional 145R10 radial choices for the 850 and Mini Cooper family.

Brand choice usually comes after the larger fitment questions are answered. First decide the correct size for your model, then decide whether you want a radial or bias-ply construction, and then compare the brands available in that exact size. On sizes with multiple makers, differences in sidewall styling, speed rating, and load information can matter just as much as the name on the sidewall.

Rim width guidance varies by size on 1968 Austin applications where that information appears. 145R12 mounts on a 4.5-inch rim, 650-13 fits a 4.50 to 5.00-inch rim, one 145R13 radial fits a 4.00 to 5.00-inch rim, 520-13 appears with 3.5-inch and 3.50 to 4.00-inch rim recommendations depending on the product, and 5.20-10 bias-ply information centers on 10-inch diameter applications without a width figure here. Different products within the same size can carry slightly different wheel recommendations.

That is why rim diameter alone is not the whole fitment story. Once you know the correct tire size for your Austin model, compare the actual wheel width against the specific tire you are considering. Cars that have changed wheels during restoration or modification deserve an extra look, since a tire can share the correct diameter but still ask for a different rim width than the wheel currently on the car.

Inner tube requirements on 1968 Austin tires depend on the exact size and product. The 145R12 Michelin radial is marked TL, meaning tubeless. Some other radial offerings, such as 145R10 and 145R13, do not all carry the same tube marking in the visible size description, so tube status can vary by product rather than staying uniform across every tire in the size. Bias-ply selections should be checked individually against the specific tire and wheel being used.

The practical step is to match the tire not only to the car, but also to the wheel design and the product's own sidewall markings. Original wheels, restored wheels, and replacement wheels may not all be set up the same way. If you are retaining factory-style wheels on a collector Austin, verify tube guidance before mounting, and replace aged tubes or valve components whenever the tire manufacturer calls for it.

A 1968 Austin should be stored in a cool, dry, dark space with the tires kept away from direct sunlight, electric motors, welders, furnaces, and other ozone-producing equipment. Maintain proper inflation, keep the car off damp soil, and move it periodically so one section of the tread is not carrying the load for months at a time. Bias-ply tires tend to flat-spot more readily during long static storage, while both bias-ply and radial tires can suffer sidewall aging if the environment is poor.

For a car that sits through much of the year, simple habits make a real difference. Roll the vehicle occasionally, use clean floor surfaces, and consider stands or tire cradles if storage will be especially long. When the car comes back into service, inspect for cracking, pressure loss, and any shape change before driving at speed, since storage damage often appears before tread wear becomes an issue.

Tires on a 1968 Austin are usually judged more by age than by mileage, because many surviving cars are driven sparingly. A sensible rule is to begin regular age-based evaluation around five to seven years and to treat about ten years as the point where replacement deserves serious consideration regardless of remaining tread. The DOT date code, overall condition, storage history, and how the tire has been used all matter.

Collector cars can fool owners because a tire may look presentable and still be too old for confident road use. A lightly used Austin that spends long periods parked may age out its tires long before it wears them out. If you do not know the age of the tires on the car, checking date codes and scheduling a careful inspection is a better starting point than relying on tread depth alone.

Tires on a 1968 Austin should be inspected before every drive, with a more thorough check before any longer trip or touring event. Look for sidewall cracking, cuts, bulges, uneven wear, tread separation, and pressure loss. Any Austin running tube-type service should also have its valve stems and tube-related hardware checked closely, since leaks can develop even when the outer tire still looks sound.

Frequent inspection matters on older cars because their annual mileage is often low and their storage time is often high. Small problems can sit unnoticed until the first extended run of the season. A quick walkaround before local use and a detailed examination before a long drive can catch age-related issues early, especially on compact British cars where tire size, ride quality, and steering feel are sensitive to inflation and condition.

A 1968 Austin 1100 would have been associated with a period in which bias-ply tires were still a familiar original fitment, even as radial construction was becoming increasingly important on many European cars. For the 1100, the relevant pair is 5.50-12 in bias-ply form and 145R12 in radial form, both on 12-inch wheels. Original-market details could vary by destination market, trim expectations, and how the car was equipped when new.

That is why restoration work benefits from separating historical correctness from later owner preference. If your goal is a factory-style presentation, start by confirming which of the two constructions aligns with your particular car's market and restoration standard. Marque clubs, period road tests, and factory literature are the right places to confirm market-specific details before you commit to a final sidewall style or construction.

Correct tire fitment matters on a 1968 Austin because judges and knowledgeable enthusiasts often notice size, construction, and sidewall style very quickly. A car restored for originality can lose credibility if it wears the wrong overall size, a radial where a period-style bias-ply is expected, or a sidewall treatment that does not suit the era and market. The same principle applies whether the car is an 850, 1100, A 40, America, Mini Cooper, or 1800.

The practical standard depends on the event. Some gatherings reward tasteful driving-oriented choices, while marque judging tends to care more about period consistency. If your Austin will be shown seriously, decide early whether the build is restoration-first or road-use-first, then match the tire's construction and appearance to that goal. Event rules and Austin marque specialists are the best final authority for class-specific expectations.

For the 1968 Austin 1800, both Coker Classic and US Royal offer 650-13 bias-ply tires with the same published load figure of 1150 pounds at 32 psi and the same 13-inch fitment on 4.50 to 5.00-inch rims. The visible differences are centered on brand identity and sidewall presentation, since both brands appear in narrow whitewall and wide whitewall versions. Weight is the same at 18 pounds across those 650-13 choices.

That means the decision is less about basic fitment and more about the look you want on the car. A narrow whitewall gives a subtler period accent, while a wide whitewall creates a stronger visual statement. If your 1800 restoration is being judged, compare period photos and event expectations. If the car is a driver, choose the sidewall style that best fits the way you want the car to present.

1968 Austin tires can be appropriate for highway driving when they are the correct size, in sound condition, and used within their stated speed and load limits. Among the radial products here, S-rated tires are capped at 112 mph and H-rated tires at 130 mph. Bias-ply fitments for 1968 Austin models are more about period construction and appearance, while the vehicle's own age, braking, steering, and suspension condition often matter as much as the tire on ordinary highway trips.

Safety on the road comes from the whole package, not just the sidewall code. An older Austin with fresh tires but neglected wheel bearings, weak shocks, or poor alignment will still feel unsettled at speed. Before longer highway use, make sure the tire's speed category and condition align with how the car will actually be driven, and remember that a 1968 British compact should still be operated with period-appropriate expectations.

Inflation pressure on 1968 Austin tires should start with the original vehicle recommendation for the specific model and then be checked against the tire manufacturer's own service limits. Some sizes here include load-and-pressure figures, such as 650-13 at 1150 pounds at 32 psi, one 520-13 at 770 pounds at 32 psi, another 520-13 at 1100 pounds at 60 psi, 145R10 at 694 pounds at 30 psi on some products, and 145R13 at 825 pounds at 44 psi on one product. Those figures are not interchangeable between sizes.

The key is to avoid assuming that one Austin tire pressure suits the whole 1968 range. The 850, Mini Cooper, 1100, A 40, America, and 1800 use different sizes and may need different operating pressures depending on model, axle load, and the exact tire chosen. Use the owner's manual as the vehicle baseline, then confirm you are staying within the reproduction or radial tire's own marked limits.

Before a longer drive in a 1968 Austin, inspect each tire for cracks, cuts, bulges, uneven wear, embedded debris, and correct inflation. Check the spare as carefully as the road tires, and pay close attention to valve stems and any tube-related hardware where tube-type service is being used. On cars with multiple decades of service history, also verify that wheel fasteners are secure and that the tread is not old enough to raise age-related concerns.

Tires are only one part of the preparation, but they are the part in constant contact with the road. A longer run in a vintage Austin also calls for a quick check of brakes, steering play, cooling system health, and fluid levels. If the car has been sitting, drive it locally first and recheck tire pressure afterward. That short shakedown often reveals problems before they become road-trip interruptions.