1968 Triumph Tire Fitment Guide

1968 Triumph vehicles use six sizes across five model groups. The Triumph 2000 uses 175R13 or 650-13 on 13-inch wheels. The GT6, Spitfire, and Sports Six use 155R13 or 560-13 on 13-inch wheels. The TR3, TR4, and TR4A use 165R15 or 590-15 on 15-inch wheels. Rim-width guidance varies by size: 650-13 fits 4.50- to 5.00-inch rims, 155R13 fits 4.00- to 5.50-inch rims where published, 560-13 spans 3.50 to 4.50 inches depending on tire, 165R15 fits 4.50 to 6.00 inches, and 590-15 fits 4.00 to 4.50 inches where specified.

The practical takeaway is that year and make alone are not enough for a 1968 Triumph. You need to identify whether you have the 2000 saloon, one of the compact 13-inch sports models, or a TR on 15-inch wheels before you narrow the tire choice further. Once the model is confirmed, the next step is deciding whether you want the period look and driving character of a bias-ply tire or the more familiar road manners of a radial.

On a 1968 Triumph, 560-13 is a numeric bias-ply size. The 5.60 portion is the nominal section width in inches, while the 13 is the wheel diameter in inches. This size belongs to the GT6, Spitfire, and Sports Six. Available examples include narrow whitewall and wide whitewall styles, and published rim-width fitment ranges from 3.50 to 4.50 inches depending on the tire chosen.

That code matters because it places the tire in a very different family from a modern metric radial, even when both mount on the same 13-inch wheel diameter. A buyer choosing 560-13 is usually aiming to keep the visual proportions and period-correct construction associated with a late-1960s small British sports car. Before final selection, confirm the actual wheel width on the car so the tire matches both the model and the rim.

No. 1968 Triumph models are split into distinct size groups. The 2000 uses 175R13 or 650-13, the GT6/Spitfire/Sports Six family uses 155R13 or 560-13, and the TR3/TR4/TR4A group uses 165R15 or 590-15. That means the make spans both 13-inch and 15-inch wheel diameters, with separate size families for saloon, small sports-car, and TR applications.

For a buyer, that makes model identification the first checkpoint rather than a minor detail. A Triumph owner who skips that step can easily end up comparing the right construction style but the wrong wheel diameter or section width. If your car has been modified over the years, confirm the wheel diameter stamped on the wheel or verify the tire already on the car before deciding whether to stay with original-style sizing or continue with a replacement already in use.

That choice depends on which 1968 Triumph model you own and what you want from the car. The 2000 pairs 650-13 bias-ply with 175R13 radial, the GT6/Spitfire/Sports Six family pairs 560-13 bias-ply with 155R13 radial, and the TR3/TR4/TR4A group pairs 590-15 bias-ply with 165R15 radial. Bias-ply tires keep the car in a construction style closely associated with the period, while radial tires bring a more familiar modern driving feel within the model’s original wheel-diameter family.

Owners focused on show presentation and era-correct appearance often lean toward the bias-ply option, especially where whitewall styles are part of the car’s finished look. Owners planning more regular road use often prefer the radial path, particularly on small British sports cars that see club drives or weekend touring. The key is to stay within the size family that belongs to your exact model rather than treating all 1968 Triumphs as interchangeable.

Sidewall style varies by size on 1968 Triumph applications. The 155R13 radial choices are blackwall only. The 560-13 bias-ply choices include narrow whitewall and wide whitewall styles. The 650-13 bias-ply options also include narrow whitewall and wide whitewall styles. On the TR fitments, 165R15 radial choices include blackwall, narrow whitewall, and wide whitewall, while 590-15 bias-ply choices include blackwall and wide whitewall.

For a 1968 Triumph, sidewall style is usually an appearance decision tied to the car’s intended finish and market flavor. Many British sports-car restorations lean toward blackwall for a more sporting presentation, while whitewall variations can suit certain saloon or personalized period restorations. The best approach is to match the sidewall look to the way your car is being restored or presented rather than assuming one sidewall style was universal across the entire Triumph range.

1968 Triumph tire coverage includes Coker Classic, US Royal, Michelin, Dunlop, BFGoodrich, Firestone, American Classic, and Avon. Brand availability changes by size: 650-13 comes from Coker Classic and US Royal, 155R13 comes from Michelin and Dunlop, 560-13 comes from BFGoodrich and Firestone, 165R15 comes from Coker Classic, American Classic, Firestone, and BFGoodrich, and 590-15 comes from BFGoodrich and Avon.

That brand spread gives Triumph owners several different ways to pursue the same fitment goal. Some sizes lean toward reproduction-style whitewall bias-ply offerings, while others lean toward blackwall radial choices associated with later-driving road use. When comparing brands, start with your exact size and sidewall preference first, then narrow by construction type and any published load, pressure, or speed information that matters for how you use the car.

Rim-width requirements for 1968 Triumph tires depend on the size. The 650-13 fits 4.50- to 5.00-inch rims. The 155R13 fits 4.00- to 5.50-inch rims where that guidance is published. The 560-13 spans 3.50 to 4.50 inches depending on the tire chosen. The 165R15 fits 4.50- to 6.00-inch rims, and the 590-15 fits 4.00- to 4.50-inch rims where that dimension is stated.

Those ranges are especially important on older British cars because many have seen wheel swaps over the decades. Tire size alone is not enough if the wheel currently on the car is wider or narrower than original. Before mounting a new set, measure the wheel or confirm its actual width so the tire sits correctly on the rim and keeps the car within the intended size family for that model.

Tube status on 1968 Triumph tires depends on the exact product and size. Michelin’s 155R13 carries a TL marking, which identifies it as tubeless. Other sizes do not show a universal tube marking across every product, so tube use should be treated as something that can vary by product and by the wheel itself rather than assumed for the whole year and make. That is especially important on older wheels and older construction styles.

The right way to handle tubes on a 1968 Triumph is to confirm both the tire’s sidewall marking and the wheel’s design before installation. A wheel built for tube-type service, a wire-wheel arrangement, or an older rim condition may point you in a different direction than a simple size code would suggest. Checking that detail early prevents mismatches in mounting hardware, valve stems, and service setup.

Often yes, but only within the paired sizes that belong to that specific 1968 Triumph model group. The 2000’s 650-13 and 175R13 both fit 13-inch wheels, the GT6/Spitfire/Sports Six pair of 560-13 and 155R13 both fit 13-inch wheels, and the TR3/TR4/TR4A pair of 590-15 and 165R15 both fit 15-inch wheels. Diameter compatibility is clear within each model group, but rim-width requirements still need to match the tire chosen.

That means an original wheel can often support either the bias-ply or radial path for its model family, provided the wheel width falls inside the published fitment range for the exact tire. It does not mean all Triumph wheels interchange across the whole 1968 range, since the make used both 13-inch and 15-inch applications. A quick wheel measurement before ordering is the simplest way to avoid a mismatch.

A stored 1968 Triumph should be kept away from direct sunlight, standing moisture, and ozone sources such as electric motors, battery tenders with poor ventilation, or shop equipment that sits close to the tires. Clean, dry storage and correct inflation help preserve the casing shape. Bias-ply tires on a collector car are generally more prone to flat-spotting during long periods of sitting, while any tire can suffer sidewall aging if exposed to heat and ozone over time.

For cars that sit through the off-season, roll the car periodically or support it in a way that reduces long static loading if your storage plan allows. Keep the tires covered from UV exposure and inspect them before the first drive back on the road. Owners with mixed collections often find that careful storage habits matter more to tire life than annual mileage on a lightly used 1968 Triumph.

On a 1968 Triumph, tire life should be judged more by age and condition than by mileage. Collector-car tires often age out before they wear out. A sound rule is to evaluate them closely once they reach the 5- to 7-year range and to treat around 10 years as a point where replacement deserves serious consideration, even if tread depth still looks healthy. The DOT date code on the tire helps establish age.

That matters because a low-mileage British classic can look road-ready while carrying tires that are simply too old for confident use. Sidewall cracking, hardening rubber, changes in pressure retention, or a car that has spent years parked indoors without movement can all shorten useful service life. Age planning is especially important before club tours, highway events, or any trip where the spare may also need to be called into service.

Tires on a 1968 Triumph should be inspected before every drive and again before any extended outing. Check inflation, tread condition, sidewall cracking, bulges, cuts, and any sign that the tire is not wearing evenly. On older collector cars, a brief visual check can catch problems early because the car may sit for long periods between drives. If your setup uses tube-type service, valve stems and pressure retention deserve extra attention.

Routine inspection is particularly important on light British cars, where steering feel quickly reveals problems but does not always warn you before a failure. A car that has been parked for weeks can develop flat spotting, and an old spare can be unusable when you finally need it. Making tire inspection part of the same habit as fluid checks and battery checks keeps a 1968 Triumph better prepared for regular use.

A 1968 Triumph Spitfire belongs to the model group that uses 560-13 bias-ply or 155R13 radial sizing today, but period factory fitment expectations for a British sports car of this era centered on bias-ply construction. That makes 560-13 the closer match to the construction style associated with original late-1960s delivery, while 155R13 reflects the radial alternative now available in the same model family. Original-equipment branding could vary by market and should not be assumed from a reproduction tire brand name alone.

For restoration work, the safest path is to confirm the car’s target standard before selecting the tire. A local marque specialist, period sales literature, and Triumph club judging guidance can help determine whether your specific car should wear a blackwall, a whitewall variation, or a certain construction style for the event or market you are restoring toward. That extra step matters more than simply matching a wheel diameter.

Yes. On a 1968 Triumph entered for judged display, tire size, construction type, and sidewall style all influence how authentic the car appears. A radial tire on a car restored for strict period originality can stand out immediately, just as an incorrect whitewall treatment can look out of place on a sports model even if the size is physically usable. The right fitment starts with the model and the wheel diameter it was built around.

Show expectations vary, so the best standard is the one used by the event, club, or marque authority you plan to present with. Some owners accept a visual compromise for road use, while others want a tire that matches the car’s late-1960s character as closely as possible. Deciding that goal up front keeps you from buying a technically serviceable tire that works against the way the car is being judged.

For a 1968 Triumph using 155R13, Michelin XAS and Dunlop SP Sport Aquajet are both blackwall radial options, but they do differ in published details. The Michelin carries a 155HR13 78H TL marking and fits a 4.00- to 5.50-inch rim range where stated. The Dunlop is marked 155R13 78H and carries a published maximum load of 937 pounds. Both are H-rated, which corresponds to a 130 mph speed ceiling.

In practical terms, the decision is less about overall size and more about the finer details that matter to your wheel and restoration plan. One tire gives a clearly stated tubeless marking and rim-width range, while the other publishes its load figure in a way some buyers may want to compare against their intended use. If your car sees regular driving, those specification differences are worth checking alongside visual preference and brand character.

Yes, when the tires are the correct size for the model, in good condition, properly inflated, and matched to the way the car is used. The H-rated 155R13 and the H-rated Avon 590H15 carry a 130 mph speed ceiling, which is well beyond normal U.S. highway speeds. Other sizes here do not all publish a speed letter, so they should be treated according to the individual tire’s sidewall markings and intended construction style rather than assumed equal.

With a 1968 Triumph, tire capability is only part of the highway equation. Brake condition, steering play, suspension wear, alignment, and the general mechanical state of the car often matter just as much as the tire itself on an older British vehicle. A fresh, properly sized tire can support safe road use, but it should be part of a complete pre-drive assessment rather than the sole measure of highway readiness.

Inflation pressure on a 1968 Triumph should begin with the vehicle manufacturer’s recommendation for the model, then be checked against the tire’s own published rating. Several sizes here include load-and-pressure figures: 650-13 is rated at 1,150 pounds at 32 psi, 560-13 at 850 pounds at 30 psi, 165R15 from 1,168 pounds at 35 psi to 1,170 pounds at 36 psi depending on tire, and 590-15 up to 1,050 pounds at 32 psi or 1,018 pounds where separately published.

Those figures are not a universal instruction to inflate every tire on every 1968 Triumph to the same pressure. They are part of the tire’s own load-carrying specification and must be interpreted alongside the car’s original pressure guidance, weight distribution, and use. The right pressure for a Spitfire-sized tire is not automatically the right pressure for a TR fitment, so keep each size within its own application.

Before a longer drive in a 1968 Triumph, inspect the tires for cracking, cuts, bulges, irregular wear, and correct cold pressure. Check that the spare is inflated and usable, and pay attention to valve stems, especially if your setup involves tube-type service or older wheels. On a car that has been parked for weeks, look for flat spotting and confirm that each tire is holding air consistently before leaving.

A longer trip also deserves a broader mechanical walkaround because tire confidence depends on the rest of the car. Wheel bearings, brakes, steering components, and suspension condition all affect how a vintage Triumph behaves on the road. The smartest approach is to treat the tires as one part of a full touring checklist, particularly if the car has not been driven regularly or is returning to service after storage.