The 1978 Triumph TR8 sits at an interesting point in British sports car history, pairing wedge-era styling with the more muscular character that made the model stand apart from earlier Triumph roadsters. For owners today, tire selection is less about decoding multiple factory fitments and more about choosing the right version of the TR8’s single primary size. This car uses a 185/70R13 radial on a 13-inch rim, which keeps the fitment conversation focused on construction consistency, brand character, and sidewall presentation. Available choices range from blackwall performance-oriented radials to redline and wide whitewall options, so the right pick depends on whether the goal is road use, period-style appearance, or both.
Which Tire Size Is Right for The 1978 Triumph TR8
The 1978 Triumph TR8 uses one primary tire size: 185/70R13, a radial tire built for a 13-inch rim. The Base model shares that same fitment, so the main decision is not which size fits, but which 185/70R13 tire best matches the car’s appearance, driving use, and wheel specifications.
A 185/70R13 size uses a 185-millimeter nominal section width, a 70-series profile, radial construction, and a 13-inch rim diameter. On the 1978 Triumph TR8, that means the fitment stays in a modern metric radial format rather than an older bias-ply or alphanumeric size system. Available choices include BFGoodrich, Avon, Dunlop, Michelin, and Vredestein, with blackwall, redline, and wide whitewall sidewall treatments depending on the tire series. This size keeps selection focused on the kind of look and road manners you want while still confirming wheel width and overall vehicle setup.
Sub-model fitment is straightforward for the 1978 Triumph TR8. The covered sub-model uses the same 185/70R13 radial size, so the key step is choosing the right tire within that fitment rather than sorting through different factory size combinations.
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1978 Triumph TR8 Base
The 1978 Triumph TR8 Base uses the same 185/70R13 radial fitment as the core model. That keeps tire selection centered on brand, tire series, sidewall style, and wheel-width compatibility instead of needing to sort between multiple primary sizes.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Best 1978 Triumph TR8 Tires for Sale
Available 185/70R13 choices for the 1978 Triumph TR8 span BFGoodrich, Avon, Dunlop, Michelin, and Vredestein. The product grid includes blackwall, redline, and wide whitewall radials across several series, with some variation in rim-width specifications and load figures.
Common 1978 Triumph TR8 tire questions usually come down to the 185/70R13 fitment, 13-inch rim compatibility, sidewall and brand choices, and what to inspect before putting a collector-era sports car back on the road.
Tire Size & Fitment
What tire size fits a 1978 Triumph TR8?
The 1978 Triumph TR8 uses a 185/70R13 radial tire. That size combines a 185-millimeter nominal section width, a 70-series profile, and a 13-inch rim diameter, which makes it a straightforward modern metric radial fitment rather than an older bias-ply size designation.
Since there is one primary size for this model, the main job is choosing the right 185/70R13 tire rather than sorting through several fitments. Check the actual wheel diameter and wheel width on the car, especially if it has been changed over the years, then compare sidewall style, tire series, and intended road use.
What size rim does a 1978 Triumph TR8 use?
The primary tire fitment for the 1978 Triumph TR8 is built around a 13-inch rim. The 185/70R13 size confirms that rim diameter, and the available products in this fitment are all designed for 13-inch wheels.
Rim diameter is only part of the fitment picture, so wheel width still matters when choosing among available tires. Some 185/70R13 products call for different rim-width ranges, so it is worth measuring the wheels on the car before choosing between appearance-focused options and more performance-oriented blackwall radials.
Does the 1978 Triumph TR8 Base use the same tire size?
Yes. The 1978 Triumph TR8 Base uses the same 185/70R13 radial tire size as the core TR8 fitment. That keeps the fitment process simple and avoids the need to sort between multiple sub-model tire sizes for this year.
Even with shared fitment, the actual tire choice can still vary depending on the look and use of the car. A Base model owner may be comparing blackwall sport-oriented tires against redline or wide whitewall versions, so wheel width, sidewall preference, and the overall presentation of the car become the next important decisions.
Choosing the Right Tire
What should I consider when choosing a 185/70R13 tire for a 1978 Triumph TR8?
Start with the correct size and construction: the 1978 Triumph TR8 uses a 185/70R13 radial on a 13-inch rim. From there, the meaningful differences are tire series, sidewall style, rim-width specification, and product details such as stated load capacity or weight where those figures are given.
A TR8 used mainly for show or vintage appearance may lead you toward a redline or wide whitewall radial, while a road-driven car may keep the focus on blackwall sport and touring-style options. Matching the tire to the actual wheel width and the car’s intended use usually matters more than choosing by brand name alone.
What sidewall styles are available for 1978 Triumph TR8 tires?
The 1978 Triumph TR8 has 185/70R13 tire options in several sidewall styles, including blackwall, redline, and wide whitewall. Those choices appear within radial products, so the decision is largely about visual presentation rather than switching between bias-ply and radial construction.
Blackwall choices tend to suit a more understated or performance-oriented look, while redline and wide whitewall versions give the car a stronger period-style statement. Since sidewall appearance can change the character of the car quickly, it helps to consider the TR8’s wheels, paint, and restoration direction before selecting a style.
What brands offer tires for the 1978 Triumph TR8?
185/70R13 tires for the 1978 Triumph TR8 are available from BFGoodrich, Avon, Dunlop, Michelin, and Vredestein. Those brands cover a mix of traditional-looking radial choices and more sporting blackwall offerings within the same basic fitment.
The useful comparison is not simply brand versus brand, but which tire series and sidewall treatment best suits the car. Some options include broader appearance variety, while others focus on blackwall presentation, so wheel width, load figure, and the way the car will actually be driven should shape the final decision.
Restoration & Appearance
Which tire should I choose for a period-style 1978 Triumph TR8?
A period-style 1978 Triumph TR8 still starts with the correct 185/70R13 radial size. Within that fitment, the look can shift notably depending on whether the car wears a blackwall tire for a more restrained sports-car presentation or a redline or wide whitewall for a stronger vintage visual statement.
Choosing for appearance works best when size, wheel compatibility, and the overall style of the car are considered together. If exact originality matters at a high level, it is worth checking marque-specific references and restoration documentation, since a tire’s available sidewall treatment does not automatically make it exact to the car’s original delivery.
How does tire construction affect the appearance of a restored 1978 Triumph TR8?
On a 1978 Triumph TR8, construction is less of an appearance debate than on many older collector cars because the primary fitment is already radial. The visual differences here come more from sidewall treatment and tire series than from choosing between bias-ply and radial construction.
That makes the restoration decision more refined: the tire still needs to look right on the car while matching the wheel setup and intended use. A blackwall radial keeps a more understated sports-car look, while redline or wide whitewall options can push the presentation in a more stylized, restoration-oriented direction.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1978 Triumph TR8?
Yes. Even though the primary tire size for a 1978 Triumph TR8 is 185/70R13, modifications can change what works on the car in practice. Aftermarket wheels, altered wheel width, suspension changes, ride-height adjustments, or body modifications can all affect clearance and how the tire sits under the car.
A car that no longer has its original-style wheel and suspension setup should be measured before any tire is chosen. Confirming rim diameter is only the first step; steering clearance, fender clearance, and the actual wheel width need to match the tire you are considering, especially with low-use collector cars that may have been modified years ago.
What should I inspect before driving a 1978 Triumph TR8 on new tires?
Before driving a 1978 Triumph TR8 on new tires, inspect the wheels for correct diameter and width, check valve stems, and make sure the tires are inflated properly for the setup being used. It is also wise to look over suspension, alignment-related wear points, and any signs of rubbing or clearance issues.
Collector cars often spend long periods parked, so age-related issues elsewhere on the car can show up as soon as fresh tires are installed. A careful road-use check should include tread-to-body clearance at full steering lock, visible sidewall condition after initial miles, and confirmation that the car tracks evenly without vibration or air loss.
How should 185/70R13 tires on a collector 1978 Triumph TR8 be maintained?
185/70R13 tires on a collector 1978 Triumph TR8 should be maintained with regular pressure checks, periodic visual inspections, and protection from long-term heat, sunlight, moisture, and ozone exposure during storage. Low annual mileage does not stop tires from aging, so condition matters just as much as tread depth.
Routine inspection should look for cracking, bulges, cuts, irregular wear, and slow air loss. Moving the car occasionally, keeping the suspension in sound condition, and checking the tires before longer drives can help catch problems early, especially on a classic sports car that may sit for extended periods between outings.
