1979 Triumph Tire Fitment Guide

1979 Triumph vehicles use four sizes across three models: 155R13 and 560-13 for the Spitfire, 185/70R13 and 185R13 for the TR7, and 185/70R13 for the TR8. All four sizes mount on 13-inch wheels. Where rim-width guidance appears on the tire itself, 155R13 fits 4.00 to 5.50-inch rims, 560-13 fits 3.50 to 4.50-inch rims depending on the tire, and 185/70R13 fits roughly 4.5 to 6.5-inch rims depending on brand.

That means the key fitment question is the model first, then the exact size family for that model. A Spitfire owner may be choosing between bias-ply and radial construction, while a TR7 owner may be comparing two radial profiles, and a TR8 owner is centered on 185/70R13. Verifying the wheel width on the actual car before ordering is especially worthwhile when more than one tire in the same size family is under consideration.

On a 1979 Triumph, 560-13 is a traditional numeric bias-ply size. The 5.60 figure is the nominal section width, and the 13 is the rim diameter in inches. On this year Triumph range, 560-13 is a Spitfire-only fitment rather than a universal size for every model, and it appears in classic bias-ply construction with whitewall sidewall treatments.

That code matters because it signals both the tire's proportions and its era-correct construction. A buyer looking at a Spitfire can usually treat 560-13 as the more vintage visual and driving choice, especially for a car restored with period appearance in mind. It is also important to match the tire to the wheel width, since 560-13 products cover a narrower wheel range than the radial sizes used elsewhere in the 1979 Triumph lineup.

On 1979 Triumph tires, 155R13 and 185R13 are radial metric sizes with 155-millimeter and 185-millimeter section widths, both for 13-inch rims. Because these sizes do not show an aspect ratio, they are conventionally treated as 80-series radial fitments. The 155R13 belongs to the Spitfire, while 185R13 belongs to the TR7, so they are not interchangeable across the full 1979 Triumph range just because both share the same format.

Modern buyers often recognize 185/70R13 more quickly than these older metric sizes, but 155R13 and 185R13 are still very important when the goal is to stay close to the original profile family used on the car. For a Spitfire or TR7, the code helps distinguish a taller-profile radial from a lower-profile 70-series option. Checking the sidewall marking carefully prevents confusion between two sizes that may look similar at a glance but serve different models and visual outcomes.

For a 1979 Triumph Spitfire, the 155R13 and 560-13 serve different priorities. The 155R13 is a radial size available in blackwall form from Michelin and Dunlop, while the 560-13 is a bias-ply size offered with narrow whitewall and wide whitewall treatments from BFGoodrich and Firestone. The radial points toward later road manners, and the bias-ply keeps the more traditional construction and visual character associated with earlier tire practice.

That makes the decision less about simple fitment and more about the kind of Spitfire you want to present and drive. A restoration leaning toward period appearance will usually favor the numeric bias-ply route, while a driver-focused Spitfire often leans toward the radial. Before making the final call, confirm the wheel width on the car and decide whether blackwall or whitewall appearance is part of the overall look you want to preserve.

1979 Triumph tires cover several distinct sidewall styles depending on size. The Spitfire's 155R13 radial is available as a blackwall, while its 560-13 bias-ply appears in narrow whitewall and wide whitewall versions. The TR7 and TR8 size 185/70R13 offers blackwall, redline, and wide whitewall choices, and the TR7-only 185R13 appears as a blackwall.

For a late-1970s British sports car, blackwall is usually the easiest path when the goal is a broadly authentic sporting look, especially on TR7 and TR8 applications. Whitewalls and redlines shift the visual character more dramatically and may suit a personalized restoration better than a factory-style presentation. If the car will be shown, it is wise to compare the sidewall treatment to period photography, sales literature, and the standards used by the specific club or judging body.

1979 Triumph vehicles are covered by several well-known brands across the four sizes. Michelin and Dunlop make 155R13 options for the Spitfire, BFGoodrich and Firestone cover 560-13 for the Spitfire, BFGoodrich, Avon, and Dunlop make 185/70R13 tires for the TR7 and TR8, and Michelin offers the 185R13 fitment for the TR7. Those choices span both classic American reproduction lines and established European sporting names.

Brand choice often comes down to the combination of construction, sidewall appearance, and how closely you want the tire's personality to match the car's intended use. A touring-oriented owner may focus on a radial from a European heritage brand, while a restoration owner may care more about a whitewall or redline treatment than the name on the sidewall. Narrowing the search by exact size first makes the brand decision much simpler.

Rim-width guidance for 1979 Triumph tires varies by size. The 155R13 fits 4.00 to 5.50-inch rims, the 560-13 fits from 3.50 to 4.50 inches depending on the exact tire, and the 185/70R13 fits from about 4.5 to 6.5 inches depending on brand. Every one of these sizes uses a 13-inch rim diameter, but width still matters because it affects how the tire sits and performs on the wheel.

That makes wheel measurement an important part of ordering, especially on cars that may have changed wheels during decades of ownership. A Spitfire with a narrow original-style wheel and a TR7 with a wider sport wheel can both be 13-inch cars while still needing different tire-to-rim pairings. Measuring the actual wheel or checking the wheel stamp is the cleanest way to avoid choosing a tire that is technically the right diameter but wrong for the rim width.

Inner-tube status depends on the exact 1979 Triumph size and tire. The Michelin 155HR13 and Michelin 185HR13 carry tubeless markings, while the 155R13 size as a whole varies by product because not every example shows the same tube notation on the sidewall marking. The bias-ply 560-13 products and the 185/70R13 products do not all carry the same explicit tube information in the marking, so the tire's own sidewall and the wheel type should guide the final setup.

The practical rule is to match the tube decision to both the specific tire and the wheel you are using, rather than assuming all tires in the same size are handled the same way. Original steel wheels, wire wheels, and older rim conditions can each change the answer. Confirming tube use before mounting also helps you choose the correct valve stem and avoid redoing the installation after the tire is already on the wheel.

All 1979 Triumph tire sizes in this range share a 13-inch rim diameter, so diameter compatibility is consistent across the year. That does not mean every 13-inch wheel is suitable for every tire width or profile. The rim-width ranges differ meaningfully between the Spitfire's narrower 560-13 and 155R13 fitments and the wider 185/70R13 tires used on the TR7 and TR8.

A buyer should think of wheel reuse in two steps: first confirm the car's original or current wheel diameter, then confirm the wheel width against the tire under consideration. That is especially important for a TR7 owner comparing 185R13 and 185/70R13, or for a Spitfire owner moving from a narrow bias-ply setup to a radial. Shared diameter makes the conversation easier, but width is what determines whether the tire and wheel are a proper pair.

A 1979 Triumph stores best in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, welders, and other ozone sources that can age rubber. Keep the tires properly inflated, avoid prolonged contact with standing moisture, and move the car periodically if it will sit for extended periods. Bias-ply tires such as 560-13 are more prone to temporary flat-spotting during long static storage than the radial sizes used on the Spitfire, TR7, and TR8.

For a longer lay-up, many collectors either roll the car a short distance every few weeks or support it in a way that reduces continuous load on one patch of tread. Clean, bare concrete is generally better than dirt or damp surfaces, and tire covers can help if the storage area sees stray light. A few simple habits during storage often matter more to tire life on a hobby-driven Triumph than annual mileage does.

Tires on a 1979 Triumph are usually aged out before they are worn out. Collector-car practice is to begin evaluating tires closely once they reach about five to seven years of age and to treat around ten years as a strong replacement point even if tread remains. The DOT date code, sidewall condition, and the way the tire has been stored matter more than mileage on cars like a Spitfire, TR7, or TR8 that may see occasional rather than daily use.

That age-based approach is important because a low-mile car can still be riding on rubber that has hardened, cracked, or lost resilience. Enthusiasts sometimes focus on tread depth because the tires look almost new, but the calendar is often the more meaningful measure. Checking the date code when the car comes into your garage or before a touring season begins is one of the simplest ways to plan replacement before age becomes a safety concern.

Tires on a 1979 Triumph should be inspected before every drive and more thoroughly before any longer outing. Look for sidewall cracking, cuts, bulges, irregular tread wear, and signs that the tire is losing pressure between drives. On cars using tube-related setups or older wheels, it is also smart to check valve stems and watch for slow leaks that can be easy to miss on a collector car parked for days or weeks at a time.

A short walk-around catches many problems before they become roadside issues, especially on older sports cars that often sit longer than modern daily drivers. Longer drives deserve an extra check with a pressure gauge and a quick inspection of the spare as well. Making tire inspection part of the same routine as fluid checks and brake checks is good practice for any late-1970s Triumph that still sees real road use.

The 1979 Triumph Spitfire falls into a period when radial tires were widely established, and 155R13 is the radial fitment associated with the model here, alongside a 560-13 bias-ply alternative used in the same year-and-make range for Spitfire fitment. That means a Spitfire owner will often encounter both a later-era radial path and a more traditional bias-ply path when restoring the car. Original market, wheel choice, and restoration goal can all influence which route is the better historical match.

Because late-production British sports cars can vary by destination market and owner history, it is wise to verify the car against factory literature, period photos, or a Triumph marque club before making an originality claim. The most important thing is to keep size family, sidewall appearance, and construction aligned with the story you want the car to tell. That approach is usually more convincing than focusing on brand alone unless you have strong provenance for the individual car.

Correct tire fitment absolutely matters when a 1979 Triumph is judged for originality. Size, construction, profile, and sidewall style all affect whether the car looks appropriate for its year and model. A Spitfire wearing a tall blackwall radial, a numeric whitewall bias-ply, or a TR7 on a lower-profile 185/70R13 can each create a different period impression, and judges often notice those differences even when the wheel diameter itself is correct.

Show standards are not always identical from one club or event to another, so the best course is to match the tire to the exact class the car will enter. A preservation-minded class may expect a different look than a touring class or a personalized restoration class. If trophies matter, compare your planned tire choice against event rules and Triumph club guidance before mounting a set that could look appealing on the road but out of character on the show field.

For the 1979 Triumph radial fitments where both appear, Michelin XAS-FF and Dunlop SP Sport Aquajet differ in size application and sidewall marking details. In 155R13, Michelin uses a 155HR13 78H TL marking with a 4.00 to 5.50-inch rim-width range and a 20-pound tire weight, while Dunlop appears as 155R13 78H with a 937-pound load figure and the same 20-pound weight. In the wider sporting fitments, Dunlop also appears in 185/70VR13 82V form, giving it a higher stated speed category there than the H-rated 155-size examples.

That means the comparison should start with the exact size your Triumph uses, not with brand preference alone. A Spitfire owner choosing between Michelin and Dunlop in 155R13 is comparing two blackwall radial interpretations of the same fitment family, while a TR7 or TR8 owner looking at Dunlop in 185/70R13 is stepping into a different profile and speed-rating range altogether. Matching the comparison to the car prevents blending together products that serve different models and driving expectations.

1979 Triumph tires can be suitable for highway driving when they are in the correct size, properly mounted, correctly inflated, and in sound condition. The radial choices here include H-rated examples to 130 mph and a V-rated example to 149 mph, which comfortably exceed normal U.S. highway speeds. The 560-13 bias-ply Spitfire option should be approached as a vintage-construction tire, with the understanding that construction feel and response differ from a radial even when the tire is fully serviceable.

In real-world use, the car's age, brakes, suspension condition, alignment, and overall mechanical health are often just as important as the tire's speed symbol. A TR7 or TR8 prepared for touring may feel happiest on a radial, while a show-focused Spitfire on bias-ply tires may be used more selectively. The smart approach is to match the tire to the car's intended use and then inspect the entire chassis before asking any late-1970s Triumph to cover long highway miles.

Inflation pressure on a 1979 Triumph should begin with the vehicle manufacturer's recommendation for the car and then be checked against the tire's own sidewall information. Among the tires carrying explicit load-and-pressure markings here, 560-13 appears at 850 pounds at 30 psi, and 185/70R13 appears at 1,135 pounds at 35 psi on some products. Those figures are tire ratings, not blanket instructions to run every 1979 Triumph at the same pressure.

The practical takeaway is to avoid transferring a pressure number from one size family to another just because all of them fit 13-inch wheels. A Spitfire on 560-13 bias-ply tires, a Spitfire on 155R13 radials, and a TR8 on 185/70R13 can each call for a different operating pressure once vehicle weight, handling balance, and the tire maker's guidance are considered. Check pressure cold, recheck after storage, and use the car's manual as the first reference point.

Before a longer drive in a 1979 Triumph, inspect each tire for cracking, cuts, bulges, punctures, uneven wear, and proper cold inflation. Check the spare as carefully as the four road tires, since an old spare is common on collector cars and may be the least trustworthy tire on the car. If your setup uses tubes or older valve hardware, inspect the valve stems and pay attention to any tire that has been slowly losing air between outings.

A tire inspection is only one part of a broader pre-trip routine on a late-1970s British sports car. Wheel fastener security, brake feel, fluid levels, lights, and charging-system health all deserve attention before the first highway mile. Taking ten extra minutes in the garage is usually enough to catch the age-related issues that collector cars hide well until they are asked to run farther and faster than they do on a short local drive.