1978 Aston Martin Tire Fitment Guide

1978 Aston Martin vehicles use one tire size: GR70-15. That size applies to the 1978 Aston Martin AM and mounts on a 15-inch rim. The available GR70-15 products are built for rim widths ranging from 7.0 to 8.0 inches, with some versions centered more tightly around 7.50 to 8.0 inches or 8 inches.

Because there is only one fitment at the year-and-make level, most buyers do not need to sort through multiple diameter choices. The practical job is to confirm that your car still has the correct 15-inch wheels, then choose the sidewall treatment that best matches your restoration goals and the visual character you want from the car.

GR70-15 is an alphanumeric radial tire size. In this format, the letter-and-number combination identifies the tire's size class, the presence of radial construction distinguishes it from older bias-ply sizing systems, and the 15 refers to a 15-inch wheel diameter. It is a period-correct late-1970s style of sizing that sits squarely in the era when radial tires had become common on premium road cars.

That matters because a modern buyer may mistake the code for a model name rather than a size designation. When you compare GR70-15 choices for a 1978 Aston Martin, the fitment remains the same, but the sidewall appearance and product series can change the look of the car in a noticeable way.

Yes. At the year-and-make level, 1978 Aston Martin uses one tire size across the covered model range, and that size is GR70-15 for the AM. There is no split here between one model taking a narrower tire and another taking a different wheel diameter.

That simplifies the fitment side of the decision, but it does not eliminate the need to look closely at the car itself. Aston Martins of this era are often restored, serviced, and modified over time, so it is still smart to verify the wheel diameter on the car and compare the tire you choose against the wheel's actual width before mounting.

1978 Aston Martin tires in GR70-15 are available with two sidewall treatments: Pin-White-Stripe and RWL, or raised white letters. Both appear on Goodyear Bias Look Radial products. Each preserves a strong period feel, but they create a different visual impression on the car, especially on a grand touring Aston Martin where wheel-and-tire presentation has a major effect on stance.

Pin-White-Stripe usually reads as more restrained and formal, which suits a refined British GT. RWL tends to look more assertive and more overtly performance-oriented. If your car is being restored toward a particular market style or show standard, check period photos, marque references, and event judging guidance before choosing between the two.

Goodyear supplies the GR70-15 fitment for 1978 Aston Martin vehicles in the current product range for this size. The available choices include GM Custom Tread, Steelgard, and Custom Wide Tread series, all using a Bias Look Radial construction and all built around the same 15-inch fitment.

With a single brand covering the size, your decision becomes more about series and sidewall appearance than brand comparison. That can actually simplify the process for a collector-car buyer, since you can focus on which tire best matches the car's intended presentation rather than trying to sort between multiple manufacturers with different overall sizing philosophies.

For the 1978 Aston Martin in GR70-15, Goodyear Steelgard appears in both RWL and Pin-White-Stripe form, while GM Custom Tread appears as a Pin White Stripe version and as Power GM Custom Tread RWL. Rim-width coverage is very similar overall, spanning from 7.0 to 8.0 inches depending on the individual product, and product weights range from 22 to 30 pounds across the available choices.

That means the most meaningful differences for most owners are visual and presentation-based rather than a change in basic fitment. If you are narrowing the field between two Goodyear series, compare the exact sidewall treatment, the wheel width on your car, and the overall look you want before deciding which one belongs on your 1978 Aston Martin.

GR70-15 tires for 1978 Aston Martin applications fit 15-inch wheels and are built for rim widths in the 7.0- to 8.0-inch range, depending on the exact product. Some versions cover 7.0 to 8.0 inches, one centers on 7.50 to 8.0 inches, and another is targeted at an 8-inch wheel.

That range is close enough that many original-style wheels will fall within it, but it is still important to verify the actual wheel width before mounting. A tire can share the correct 15-inch diameter and still be less than ideal if the wheel is outside the product's intended width window, especially on a heavier grand touring car.

The GR70-15 products for 1978 Aston Martin do not carry tube-type or tubeless markings in the size designation, so tube requirements should be confirmed against the wheel itself and the specific tire's sidewall marking. On collector cars, the wheel often determines the answer just as much as the tire does, particularly if the car still uses older wheels or restored original rims.

The practical approach is to inspect the wheel condition, check whether the wheel was designed for tubeless use, and match the setup to the tire manufacturer's marking on the product you choose. If the car has been restored or modified over the years, do not assume the current wheel matches the factory-era setup without verifying it first.

A 1978 Aston Martin should be stored in a cool, dry space away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment that can age rubber. Keep the tires clean, maintain proper inflation, and move the car periodically so one section of the tread is not carrying the load for months at a time.

Radial tires generally tolerate storage better than older bias-ply designs, but any collector tire can develop age-related cracking or flat-spotting if the car sits too long in poor conditions. If the car will be parked for an extended season, use a clean surface under the tires and consider taking some load off the suspension and tires with proper storage stands.

On a 1978 Aston Martin, tire age matters more than mileage for most owners because these cars are often driven sparingly. A good rule is to begin careful age-related evaluation around five to seven years and to treat the ten-year mark as a point where replacement deserves serious consideration, even if tread depth still looks acceptable. The DOT date code on the tire sidewall is the starting point for that timeline.

A low-mile collector car can fool its owner because the tread may still look fresh while the rubber has hardened with time. Regularly checking the date code, sidewall condition, and ride quality helps prevent relying on a tire that appears healthy but has aged out of trustworthy road use.

Tires on a 1978 Aston Martin should be inspected before every drive, and especially before any longer outing or highway trip. Look for sidewall cracking, tread wear, cuts, bulges, punctures, and any sign that the tire has lost pressure since the last drive. Valve stems deserve attention as well, since age and heat can affect them just as much as the tire itself.

That quick routine is particularly important on a hand-built grand touring car that may spend long stretches parked between drives. A few minutes in the garage can catch age-related problems early and can also help you spot alignment or suspension issues before they turn an enjoyable trip into a roadside problem.

For a 1978 Aston Martin AM, radial construction is the right starting point for originality-minded research, and GR70-15 is the applicable year-and-model size here. By the late 1970s, high-end grand touring cars commonly used radial tires rather than older bias-ply designs, so a radial format is consistent with the period character of the car.

Original-equipment details could still vary by market, wheel package, and delivery specification, so concours-level restoration should not stop at the basic size alone. If you are aiming for exact authenticity, compare your car against factory literature, period photography, and Aston Martin marque specialists before settling on a particular sidewall style or brand presentation.

Yes, correct tire fitment can matter quite a bit when showing a 1978 Aston Martin. Judges and knowledgeable enthusiasts often notice whether the size, construction type, and sidewall presentation suit the era and the car's intended appearance. On a late-1970s Aston Martin, the tire should look appropriate to a premium European grand tourer rather than to a much earlier car or a modern performance build.

That does not always mean every event applies the same standard, but visible departures from period character can stand out quickly. If your goal is serious show judging, check the event's rules and consult Aston Martin clubs or registries so your tire choice supports the car's authenticity instead of distracting from it.

Goodyear Steelgard and Goodyear Power GM Custom Tread both serve the 1978 Aston Martin in GR70-15, but they differ in presentation and in some physical details. Steelgard appears in both RWL and Pin White formats and carries weights around 29 to 30 pounds, while Power GM Custom Tread RWL carries an RWL appearance and a lighter 22-pound weight. Their wheel-fit windows remain within the same general 15-inch, 7.0- to 8.0-inch range.

For a restoration-minded owner, that means the choice is best made by looking closely at the visual style you want on the car and how your wheel width compares to the product's intended range. The right answer is often the one that looks most believable on the car while still matching the wheel properly.

A properly maintained GR70-15 radial in good condition can be appropriate for normal highway driving on a 1978 Aston Martin. The available products here do not show explicit speed letters in the size marking, so the practical limit is not something to guess from the sidewall code alone. On a late-1970s Aston Martin, overall mechanical condition, alignment, suspension health, and brake condition are just as important to safe highway travel as the tire itself.

That is why age, inflation, and condition matter more than simply seeing usable tread. Before any sustained highway run, make sure the tires are fresh enough for road use, properly inflated, free of visible defects, and mounted on wheels that match the tire's intended width range.

Inflation pressure for a 1978 Aston Martin should be set by the vehicle's factory recommendation and then checked against the tire manufacturer's guidance for the exact GR70-15 product you choose. No universal pressure should be borrowed from another size or another car, even when the wheel diameter matches. Each tire and vehicle combination has its own intended operating range.

The best method is to start with the owner's manual or factory placard for the car, then make sure the tire itself is being used within its design limits. If your car has non-original wheels, a restoration-era suspension setup, or a load condition different from normal solo driving, it is worth reviewing the setup carefully before settling on final pressures.

Before a longer drive in a 1978 Aston Martin, inspect each tire for cracks, cuts, bulges, uneven wear, and proper inflation, and check that the valve stems are sound. Confirm that the spare is usable and inflated as well. Because the car is from the late 1970s, the tire inspection should be part of a broader pre-drive check that includes brakes, steering, suspension, fluid levels, and cooling.

Aston Martins are rewarding road cars, but age affects every mechanical system, not just the tires. A careful once-over before departure reduces the chances of heat-related or age-related trouble and gives you a much better idea of whether the car is ready for sustained speeds and distance rather than a short local outing.