1959 AC Tire Fitment Guide

Three tire sizes fit 1959 AC vehicles, and they are split by model. The AC Ace uses 550-16, while the AC Saloon uses either 185R16 or 670-16. All three sizes mount on 16-inch wheels, but the listed rim-width ranges differ by size and by individual tire, including 3.25 to 4.00 inches on some 550-16 products, 4.50 to 6.00 or 5.0 to 6.5 inches on 185R16 products, and 4.50 to 5.00 inches on one 670-16 product.

That means year and make alone are not enough for a correct starting point on a 1959 AC. Ace owners can focus on one traditional bias-ply size, while Saloon owners need to decide whether they are matching the bias-ply 670-16 fitment or the radial 185R16 fitment. Before moving on to a specific tire, verify the model, measure the actual wheel, and compare it to the rim-width guidance for the exact product under consideration.

On a 1959 AC, 550-16 is a numeric bias-ply tire size. The 5.50 indicates the nominal section width in inches, and the 16 indicates the wheel diameter in inches. That format belongs to the older inch-based sizing conventions common on postwar sports cars and sedans before metric radial sizing became widespread. For 1959 AC applications, 550-16 is used on the Ace rather than the Saloon.

That sizing language matters because a 550-16 is not just another way of writing a radial metric tire. It points you toward a narrower, traditional bias-ply fitment that suits the Ace's period character and wheel setup. If your goal is to keep the car visually and mechanically aligned with its original-era presentation, that is the size family to investigate, with the final choice then narrowing by brand and sidewall style.

On a 1959 AC, 185R16 is a radial metric size. The 185 gives the nominal section width in millimeters, the R identifies radial construction, and the 16 is the wheel diameter in inches. Because no aspect ratio is written into that code, the format conventionally points to an 80-series profile. Within the 1959 AC range, 185R16 applies to the Saloon, not the Ace.

That makes 185R16 different in both format and construction from the inch-based bias-ply sizes also used on 1959 AC vehicles. A Saloon owner looking at this size is usually choosing a radial path, then comparing product details such as tube marking, speed rating, and wheel-width compatibility. It is a useful option when the car is being prepared for regular road use rather than a strict period-style bias-ply presentation.

For a 1959 AC Saloon, that choice is primarily between radial and bias-ply construction rather than between two unrelated fitments. The 185R16 is the radial option, offered in blackwall form by Michelin, Avon, and Vredestein, while the 670-16 is the bias-ply option, offered in blackwall form by Firestone and Avon. Both mount on 16-inch wheels, but they reflect different eras of tire design and different owner priorities.

A Saloon restored for period presentation will often stay with 670-16 because it preserves the traditional bias-ply appearance and feel. A Saloon intended for more frequent road driving may point you toward 185R16 because it keeps the 16-inch wheel diameter while moving into radial construction. The right answer depends on how the car is being used and whether you want to emphasize historical authenticity or a later-style radial driving experience.

Sidewall style choices on 1959 AC tires depend on size. The Ace's 550-16 size is available in both blackwall and wide whitewall form, while the Saloon's 185R16 and 670-16 offerings are blackwall only. That means the broadest cosmetic choice exists in the smaller bias-ply Ace size rather than across the full 1959 AC range.

For most British AC applications of this period, blackwall remains the most conservative and era-appropriate visual choice, especially on sporting cars and formal saloons sold in their home market style. Whitewall can still make sense for a particular restoration theme or owner preference, but it should be chosen deliberately rather than assumed as universal for 1959 AC vehicles. If show authenticity matters, compare your planned sidewall style with period photos and marque-club guidance before deciding.

Several brands cover the 1959 AC range, but they are split by size. The 550-16 Ace fitment is available from Excelsior, Avon, BFGoodrich, and Firestone. The 185R16 Saloon radial fitment is available from Michelin, Avon, and Vredestein. The 670-16 Saloon bias-ply fitment is available from Firestone and Avon.

That spread gives owners room to choose within the correct size rather than forcing one brand for the entire year and make. Some buyers will narrow the field by visual style, others by whether they want a traditional crossply or a radial, and others by details such as speed symbol or stated load figure. Once the model and size are settled, compare the available brands within that single fitment family instead of mixing size categories.

Rim-width guidance on 1959 AC tires varies by size and by the specific tire chosen. In 550-16, listed fitments include 3.25 to 4.00 inches on some products. In 185R16, listed fitments include 4.50 to 6.00 inches on one product and 5.0 to 6.5 inches on another. In 670-16, one listed product shows 4.50 to 5.00 inches. All of them use a 16-inch rim diameter, but width compatibility is more specific.

That is why a 16-inch wheel alone is not enough to confirm fitment on a 1959 AC. Measure the wheel that is actually on the car and match it to the rim-width range of the exact tire you plan to run. This is especially important on cars that may have had wheel changes over the decades, or when comparing the Saloon's radial and bias-ply options against one another.

Inner-tube status on 1959 AC tires varies by size and by product. In 185R16, at least one product is explicitly marked TT, meaning tube type, while others in the same size are not marked the same way, so tube use can vary by product. The 550-16 and 670-16 offerings are bias-ply tires, but the deciding factor should still be the specific tire's sidewall marking and the design of the wheel itself rather than assumption alone.

For a collector car, tube questions are important because wheel construction, age, and intended authenticity can all influence the final setup. Check the exact tire marking before installation and make sure the valve stem, flap if required, and wheel condition all match that configuration. If your 1959 AC still wears older original-style wheels, it is wise to review the plan with an installer familiar with vintage British applications.

All of the listed 1959 AC tire sizes use a 16-inch wheel diameter, so there is broad diameter compatibility across the year and make. That does not mean every original wheel is automatically suitable for every tire, because the available rim-width guidance differs among 550-16, 185R16, and 670-16. The Ace's 550-16 products can call for narrower wheels than the Saloon's radial 185R16 products.

A stock 1959 AC wheel can only be judged correctly once the actual model and wheel width are confirmed. Ace owners should stay within the narrower 550-16 fitment family, while Saloon owners should compare their wheel width to the specific radial or bias-ply product they want to use. Diameter may line up across the range, but width suitability still needs to be verified before mounting.

A 1959 AC should be stored in a cool, dry, dark space away from direct sunlight, electric motors, chargers, furnaces, and other ozone sources that accelerate rubber aging. Keep the tires properly inflated, avoid prolonged contact with standing moisture, and move the car occasionally so it does not sit on one footprint for months at a time. Bias-ply tires such as 550-16 and 670-16 are especially prone to temporary flat-spotting during static storage compared with radial tires.

If the car will be parked for an extended period, many owners either roll it periodically or support it in a way that reduces long-term load on the tires. A fitted car also benefits from clean wheels, clean sidewalls, and a stable indoor environment rather than outdoor covers that trap heat and moisture. Good storage habits protect both the tire structure and the appearance of a well-kept 1959 AC.

On a 1959 AC, tire age usually matters more than mileage because collector cars often accumulate miles slowly. A sensible rule is to begin evaluating tires closely once they reach roughly five to seven years of service, and to treat around ten years as a serious replacement threshold regardless of remaining tread. The DOT date code on the tire helps establish age, and visible cracking, hardening, or repeated air loss can shorten that timeline further.

That approach is especially important on a vintage car because infrequent use can make old tires look better than they actually are. A bias-ply tire on an occasionally driven Ace or Saloon may still show acceptable tread depth while no longer offering the confidence expected for road use. Age, storage conditions, and structural condition should drive the replacement decision more than odometer reading alone.

Tires on a 1959 AC should be inspected before every drive and again before any longer outing. Look for sidewall cracking, tread separation, cuts, bulges, embedded debris, and uneven wear, and confirm that each tire is holding its intended pressure. If your setup uses tube-type tires or tubes within the wheel assembly, pay close attention to valve-stem condition and any signs of slow leakage.

A short pre-drive inspection is one of the simplest ways to prevent avoidable roadside trouble in a collector car. Vintage vehicles often sit for periods, and tires can age or lose pressure between outings without much visual drama. Building a routine around pressure checks, sidewall inspection, and a quick look at the spare helps keep a 1959 AC ready for local drives as well as longer weekend events.

A 1959 AC Ace would have been associated with a bias-ply tire rather than a radial as its period-correct construction type, and the listed Ace fitment here is 550-16. That aligns with the general tire practice of late-1950s British sports cars, which commonly left the period on narrow inch-designated crossply sizes before radial adoption became more mainstream in later usage and replacement choices.

For a restoration, that points Ace owners toward the 550-16 family first, then toward the specific sidewall presentation they want, such as blackwall or wide whitewall. Original-equipment branding can vary by market and history, so the safest course is to use the correct size and construction first, then compare period photos, club records, and AC marque specialists if you are chasing event-level historical accuracy.

Correct tire fitment absolutely matters when showing a 1959 AC, especially in classes that judge authenticity closely. Size, construction type, and sidewall appearance all affect how convincing the car looks, and judges or knowledgeable enthusiasts will often notice if a bias-ply-era sports car is wearing a visibly modern-looking radial or if the sidewall treatment does not suit the car's restoration theme.

For an Ace, a move away from 550-16 bias-ply can change the car's period character immediately. For a Saloon, the question may be whether the car is being shown as a traditional bias-ply car on 670-16 or as a later-road-use car fitted with 185R16 radials. Event standards differ, so if concours points matter, use club and event guidance to confirm exactly how strict the tire expectations will be.

For a 1959 AC Saloon running 185R16, both the Michelin X Radial and the Vredestein Sprint Classic are radial blackwall tires, but their listed details are not identical. The Michelin is marked 185R16 92S TT, giving it an S speed rating up to 112 mph and an explicit tube-type marking, with a listed rim-width range of 4.50 to 6.00 inches. The Vredestein is marked 185VR16 93V, carries a V speed rating up to 149 mph, shows a listed maximum load of 1,433 lbs at 51 psi, and fits a 5.0 to 6.5 inch rim range.

That makes the comparison less about general quality and more about the exact setup you need for your Saloon. Wheel width, intended use, and whether you want the tire with an explicit tube-type marking all shape the right choice. Both sit within the same radial 16-inch fitment family, so the deciding factors are the specification details and how closely you want the finished car to follow your restoration or road-use plan.

1959 AC tires can be suitable for highway driving when they are the correct size, in good condition, properly mounted, and run within their intended limits. The available 185R16 radial products include S and V speed ratings, which correspond to 112 mph and 149 mph, while one 670-16 bias-ply option is marked H for 130 mph. Those symbols show that the tire itself may not be the limiting factor at ordinary highway speeds.

On a 1959 AC, the broader mechanical condition of the car often matters just as much as the tire. Brakes, steering, suspension, alignment, and wheel condition all influence how confidently the car can be driven at speed, especially on a lightly built sports car or an older saloon chassis. Any highway plan should begin with fresh inspection, correct inflation, and an honest assessment of the whole vehicle rather than the tire alone.

Inflation pressure for 1959 AC tires should be matched to the exact size and product you are using, not borrowed from a different fitment. Among the listed products, examples include 550-16 with a stated 840 lbs at 32 psi, 670-16 with 1,130 lbs at 30 psi, and 185R16 with 1,433 lbs at 51 psi on one product. Those figures are tire ratings, not universal car settings for every 1959 AC application.

For actual running pressure, start with the factory recommendation for your specific AC model if you have the owner's manual or trusted marque literature. Then compare that guidance with the tire maker's published limits and load information for the exact reproduction or radial product installed on the car. Never transfer a pressure figure from the Saloon's radial fitment to the Ace's bias-ply size, or from one 16-inch tire family to another.

Before a longer drive in a 1959 AC, inspect all four tires and the spare for cracks, cuts, bulges, punctures, exposed cords, and unusual wear. Verify inflation pressures, confirm that valve stems are sound, and pay extra attention to any tube-type setup so a slow leak does not go unnoticed. Wheel fastener security, wheel condition, and basic alignment behavior should be checked along with the tires.

That tire inspection should happen as part of a broader pre-trip routine on a car of this age. Fluids, brakes, steering play, cooling, charging, and lighting deserve equal attention, because a sound set of tires cannot compensate for neglected mechanical systems. A well-prepared 1959 AC is far more enjoyable on a tour or weekend run, and the tire check is one of the fastest ways to catch age-related issues before they become trip-ending problems.