1964 Triumph TR3, TR4 & TR4A Tires

The 1964 Triumph TR3, TR4 & TR4A uses two primary tire sizes: 165R15 in radial construction and 590-15 in bias-ply construction. Both sizes fit a 15-inch wheel diameter, but they represent different tire constructions and slightly different selection paths for owners choosing between a traditional vintage-style setup and a radial-equipped car.

The practical step is to confirm which construction is already on the car and whether the wheels match the tire being considered. A TR3, TR4 or TR4A that has been restored, modified, or converted over time may no longer be using its earlier setup, so checking wheel width, clearance, and the existing tire size before ordering helps keep the fitment decision accurate.

Both primary tire fitments for the 1964 Triumph TR3, TR4 & TR4A use a 15-inch rim diameter. That applies to the 165R15 radial and the 590-15 bias-ply size, so the wheel diameter stays consistent even though the tire construction changes.

Rim diameter is only the first checkpoint, because width matters too when comparing individual tires. Many 165R15 radials work across broader rim-width ranges than the 590-15 bias-ply options, so a car with non-original wheels should be measured carefully. Confirming both the diameter and actual wheel width helps narrow the right tire family before comparing brands or sidewall styles.

Yes. The 1964 Triumph TR3, TR4 & TR4A Base uses the same two fitment paths covered on this page: 165R15 as the radial size and 590-15 as the bias-ply size. That means the main difference is construction choice rather than a separate sub-model-specific wheel diameter or unique tire size.

For a buyer, that keeps the decision centered on how the car is set up today. A restoration-minded owner may lean toward 590-15 for a more traditional look, while a driver already on radial-friendly wheels may stay with 165R15. Looking at the tires currently mounted on the car is still worthwhile, especially if it has been changed over the years.

590-15 is the bias-ply tire size used on the 1964 Triumph TR3, TR4 & TR4A. It is the vintage numeric fitment path for this application and differs from the 165R15 radial option, even though both are built around the same 15-inch wheel diameter.

That distinction matters because the construction affects both appearance and setup decisions. Bias-ply tires generally suit a more traditional presentation, while owners considering a change should compare wheel width, overall dimensions, and clearance before moving to a radial equivalent. Matching all four tires in construction is also important for predictable road manners on a classic sports car.

Radial equivalents for 590-15 include 165R15 as an 80-series metric radial, P165/75R15 as a 75-series P-metric radial, and P175/70R15 as a 70-series P-metric radial. These sizes give a buyer several radial-format alternatives to compare against the original bias-ply size.

Those equivalents should be treated as comparison options rather than automatic substitutions. The recommended rim-width range associated with this equivalency is 4-5 inches, so wheel width is a key checkpoint before conversion. It also helps to review section width, overall dimensions, and fender or steering clearance, particularly on a Triumph that may have seen wheel or suspension changes over time.

That depends on what matters most for the car. The 590-15 bias-ply size keeps the traditional construction and vintage tire format, while the 165R15 radial follows the radial fitment path available for the same 15-inch wheel diameter. Both belong to the 1964 Triumph TR3, TR4 & TR4A, but they support different ownership goals.

A restoration-oriented car may stay with bias-ply for period-style appearance, while a driver-focused car may be built around radial options and their broader product selection. The best approach is to match the tire choice to the current wheel setup, the intended use of the car, and the look you want. Any construction change deserves a careful wheel and clearance check first.

Start with the basics: confirm that the car is using the 165R15 radial fitment and that the wheel width matches the tire you are considering. From there, the 165R15 market gives this Triumph a wide spread of choices in blackwall, narrow whitewall, and wide whitewall form, along with touring-oriented radial series from several well-known vintage tire brands.

Once size and wheel compatibility are confirmed, the next decision is appearance and usage. A blackwall tire keeps a restrained sports car look, while narrow or wide whitewalls create a more styled presentation. Series differences, rim-width ranges, load figures, and even tire weight can all shape the final decision, especially if the car is driven regularly rather than shown occasionally.

The available sidewall styles for the 1964 Triumph TR3, TR4 & TR4A include blackwall, narrow whitewall, and wide whitewall. In 165R15 radial form, all three appearances are available, while the 590-15 bias-ply options include blackwall and wide whitewall choices.

Sidewall style changes the character of the car visually even when the tire size stays correct. Blackwall tends to suit a simpler sports-car presentation, while whitewalls push the look in a more restoration-oriented direction. Since sidewall treatment does not answer the fitment question by itself, it makes sense to decide on size and construction first, then narrow the appearance choice within that group.

Tires for the 1964 Triumph TR3, TR4 & TR4A are available from Coker Classic, American Classic, Firestone, BFGoodrich, Michelin, Vredestein, and Avon. Most of that variety appears in the 165R15 radial category, while the 590-15 bias-ply selection is centered on BFGoodrich and Avon.

Brand choice is most useful once the right size and construction have already been narrowed down. At that stage, the buyer can compare each brand's available tire series, sidewall treatments, rim-width ranges, and load figures where relevant. Rather than looking for a single best brand, it is smarter to compare which product line matches the car's intended appearance and road use.

For a period-style presentation, 590-15 bias-ply is the most traditional starting point on a 1964 Triumph TR3, TR4 & TR4A. That size uses the vintage numeric format and keeps the car in a bias-ply construction, which aligns naturally with a more historically minded visual approach.

The final choice still depends on how strictly the car is being restored and how it will be used. Some owners want the vintage look of a bias-ply tire, while others prefer a radial in 165R15 for road use but still want a classic sidewall treatment. When exact originality matters, marque-club guidance and vehicle-specific restoration references are worth consulting before settling on a brand or sidewall style.

Tire construction changes more than road feel on a restored 1964 Triumph TR3, TR4 & TR4A; it also changes the car's visual attitude. A 590-15 bias-ply keeps a distinctly vintage tire format, while a 165R15 radial introduces a more modern sizing convention even when mounted on the same 15-inch wheel diameter.

Appearance also shifts with the sidewall treatment chosen within each construction. Blackwall, narrow whitewall, and wide whitewall options can make the same car look more understated or more dressed for show. For a restoration-oriented build, construction and sidewall should be considered together so the finished look matches the era impression you want the car to project.

Yes. Modifications can change tire fitment on a 1964 Triumph TR3, TR4 & TR4A even when the nominal tire size looks correct on paper. Aftermarket wheels, different wheel widths, altered ride height, suspension work, or body and fender changes can all influence whether a 165R15 radial or 590-15 bias-ply remains a comfortable fit.

The safest approach is to inspect the car as it sits now rather than assuming it still matches an earlier setup. Wheel width, steering clearance, suspension travel, and fender space should all be reviewed before changing size or construction. That check becomes especially important when moving from 590-15 to one of its radial-equivalent formats or when the car has been updated over time.

Before road use, inspect basic fit and condition items across the full installation. Confirm that the tires match the intended size, that they seat properly on the 15-inch wheels, and that there is no contact at the fenders, suspension, or steering stops. Tire pressure should also be set appropriately for the tire and wheel combination being used.

A classic Triumph deserves a broader once-over before the first meaningful drive. Check for air loss, visible cuts, bulges, or mounting damage, and make sure the wheels themselves are sound and clean at the bead areas. On a car that has sat for long periods, it also helps to recheck fasteners, suspension condition, and steering movement after a short shakedown run.

Collector-car tires should be inspected regularly even when the car is driven only occasionally. On a 1964 Triumph TR3, TR4 & TR4A, that means checking 165R15 radial or 590-15 bias-ply tires for cracking, cuts, bulges, uneven wear, and gradual air loss. Low-mileage use does not prevent tires from aging, so condition matters as much as tread depth.

Storage habits make a real difference on vintage sports cars. Keeping the car away from prolonged sunlight, moisture, heat, and ozone sources helps protect the sidewalls, and maintaining proper inflation reduces flat spotting during downtime. A brief inspection before each drive and a more thorough review at regular intervals are good practice, especially before highway use or longer seasonal trips.