1979 Jaguar XJS Tires

The 1979 Jaguar XJS uses two radial tire size designations: 205/70R15 and ER70-15. Both are 15-inch fitments, and both appear across the covered XJS sub-models, including the Base and Base w/alloy wheels. The difference is mainly in the sizing format, with 205/70R15 using modern metric notation and ER70-15 using a vintage alphanumeric radial designation.

That means the first step is confirming which size format is already on the car and whether the wheels remain in their intended 15-inch configuration. If the car has been modified, check actual wheel diameter and width before selecting tires, then compare the available sidewall treatments and tire series to suit either a more contemporary road-use look or a more period-style presentation.

The 1979 Jaguar XJS uses a 15-inch rim diameter with both of its primary tire fitments. That 15-inch wheel diameter is shared by the 205/70R15 metric radial and the ER70-15 alphanumeric radial, so wheel diameter remains consistent across the covered fitment options for this model year.

Rim diameter is only part of the picture, so it still helps to confirm the actual wheel width before making a final tire choice. Some 205/70R15 products are built around different approved rim-width ranges, and an older XJS may have had replacement wheels installed. Matching the tire to the wheel’s true dimensions is especially important when comparing whitewall touring tires with sportier blackwall options.

Yes. The covered 1979 Jaguar XJS sub-models share the same two radial fitment designations: 205/70R15 and ER70-15. That includes the Base and the Base w/alloy wheels, so there is no separate primary tire size split between those sub-models within this fitment group.

Even with shared fitment, it is still smart to inspect what is actually mounted on the car before ordering replacement tires. Alloy wheels, steel wheels, and later replacements can differ in width or tire preference, and many collector cars no longer wear their earlier setup. Once the wheel dimensions are confirmed, the real decision becomes choosing the right tire format, sidewall style, and intended road-use character.

Start with the basics: correct 15-inch fitment, radial construction, and a tire size that matches the wheel and the car’s intended setup. In 205/70R15, the 1979 Jaguar XJS has a wide spread of choices, from blackwall performance-oriented styles to narrow whitewall and wide whitewall options that give the car a more formal or period-style appearance.

Brand, tire series, rim-width compatibility, load capacity, and visual presentation are the main points to compare. A Michelin, Avon, or Dunlop blackwall may appeal to an owner focused on traditional grand touring character, while Maxxis, American Classic, Coker Classic, Tornel, or Travelstar whitewall offerings suit different styling goals. Matching the tire to the car’s use matters more than choosing by appearance alone.

The 1979 Jaguar XJS is available with blackwall, narrow whitewall, and wide whitewall tire presentations in its 205/70R15 fitment range. Blackwall choices appear in several sport and touring-oriented radial lines, while narrow and wide whitewall options give the car a more formal, restoration-minded appearance without changing the basic tire size.

Sidewall style changes the visual character of the XJS more than many owners expect, especially on a car with long, clean body lines and a luxury GT presence. Choosing among them depends on whether the goal is a restrained European blackwall look or a more traditional whitewall presentation. It is still important to keep the correct size and verify the wheel setup before choosing purely on appearance.

Available brands for 1979 Jaguar XJS tires include Maxxis, Michelin, Avon, American Classic, Coker Classic, Dunlop, Tornel, and Travelstar. Those brands cover a broad range of 205/70R15 offerings, with blackwall, narrow whitewall, and wide whitewall options, plus different tire series aimed at classic touring and vintage-style use.

The best way to compare them is by fitment details and intended character rather than by brand name alone. Look at the exact tire series, approved wheel-width range where stated, load figures when provided, and the visual style that suits the car. For an XJS, the decision often comes down to whether the tire should emphasize European blackwall GT character or a more classic whitewall presentation.

A period-style 1979 Jaguar XJS usually starts with preserving the correct 15-inch radial fitment and then choosing the tire format and appearance that best reflect the car’s era. ER70-15 brings a vintage alphanumeric radial designation, while 205/70R15 offers a modern metric notation with several classic-looking tire series and both blackwall and whitewall presentations.

The right choice depends on whether the restoration leans toward European grand touring character or a more formal classic presentation. Blackwall tires often maintain a restrained, sporting look, while whitewalls create a more dressed appearance. If exact originality matters, compare the tire choice against marque-specific reference material and the individual car’s history rather than assuming any available sidewall treatment is automatically correct.

On a 1979 Jaguar XJS, construction differences are less about bias-ply versus radial and more about how the radial tire is presented. Both primary fitments here are radial, but the visual effect can still change depending on whether the car wears a modern metric radial, a vintage alphanumeric radial designation, or a bias-look radial style within the available ER70-15-related offering.

That matters because restored cars are judged as much by proportion and visual tone as by raw specification. A blackwall performance radial can make the XJS look more contemporary and road-focused, while a more traditional sidewall treatment softens the overall presentation. Tire construction and styling should support the restoration’s goal, while still matching the wheel size and the car’s actual driving plans.

Yes. A 1979 Jaguar XJS may share the same primary 15-inch tire fitments across its covered sub-models, but modifications can still change what works on the car. Aftermarket wheels, altered wheel widths, suspension changes, ride-height adjustments, or body and brake upgrades can all affect clearance and influence whether a given tire choice remains appropriate.

That is why the car should be checked as it sits today, not only by its original fitment pattern. Measure wheel diameter and width, inspect inner and outer clearance at full steering travel, and look for any signs of rubbing. These steps become even more important when moving between different tire series or choosing a tire with a different visual sidewall treatment.

Before driving a 1979 Jaguar XJS on new tires, inspect the wheels for damage or corrosion, confirm the wheel size, and make sure the tires are mounted in the correct size and properly inflated. It also helps to check valve stems, wheel balance, lug hardware, and general tread and sidewall condition if any existing tires are still being reused in a rotation or spare-tire role.

A road-ready inspection should also include suspension and steering basics, especially on a collector car that may sit for long periods. Look for worn bushings, loose tie-rod ends, uneven ride height, and signs of prior rubbing inside the wheel wells. A short, careful test drive after installation helps confirm straight tracking, stable braking, and adequate clearance under normal movement.

Tires on a collector 1979 Jaguar XJS should be maintained with regular pressure checks, visual inspections, and attention to age as well as tread depth. Even if the car sees limited mileage, sidewall cracking, flat spotting, air loss, and general rubber aging can develop over time. Clean storage conditions and periodic movement help reduce some of the issues associated with long stationary periods.

Maintenance also means watching how the car wears its tires in real use. Uneven tread wear can point to alignment or suspension problems, and a grand touring car like the XJS benefits from stable chassis condition as much as correct tire size. Keep the car away from prolonged sunlight, excess heat, and ozone sources, and inspect the spare if one is carried for road trips.