By 1977, Subaru had established itself in the U.S. as a maker of compact, economical cars with practical packaging and a distinctly different character from larger domestic offerings. The DL and GL carried that formula into a market that increasingly expected efficient transportation with tidy dimensions and light steering effort. For 1977 Subaru, both models share the same two tire sizes, and the main decision is not model fitment so much as construction choice: a 6.15-13 bias-ply for an earlier-period look or a 155R13 radial for later-era road manners. Before choosing a tire, confirm whether originality or regular driving feel matters more for your car.
Which Tire Size Is Right for Your 1977 Subaru
Two tire sizes are used across 1977 Subaru vehicles, and both the DL and GL share them. The real choice centers on construction, since both sizes mount on 13-inch wheels: 6.15-13 is a bias-ply format, while 155R13 is a radial format. Understanding that distinction before choosing a product saves time and helps match the tire to the way the car will be used.
Year(s): 1977|Fit(s): DL, GL|Construction: Radial|Rim: 13 in
155R13 is a metric radial size with a nominal section width of 155 millimeters and a 13-inch rim diameter; in this style of sizing, the absent aspect ratio conventionally indicates an 80-series profile. Michelin and Dunlop offer this size in Blackwall form, and the available products include H-rated versions with a 130 mph speed ceiling; Michelin is marked TL while tube status varies by product across the size. This is the natural choice for an owner who wants radial construction and a later-style driving character while staying within the original 13-inch wheel diameter.
Year(s): 1977|Fit(s): DL, GL|Construction: Bias Ply|Rim: 13-in rim
6.15-13 is a numeric bias-ply size in which 6.15 refers to the nominal section width and 13 is the rim diameter in inches. This size is specific to both 1977 Subaru DL and GL models rather than to one trim alone, and it represents the traditional bias-ply construction used before radial sizing became dominant. It suits owners focused on preserving a more period-correct look and feel for a late-1970s Subaru built around compact 13-inch wheels.
Because both sizes use a 13-inch rim diameter, they can often be used on the same wheels after confirming the wheel width against the tire's approved range.
1977 Subaru Models
Two Subaru models are covered for 1977: the DL and the GL. They share the same tire sizes, so the decision is less about model-specific fitment and more about how you want the car to present and drive. Select a model below for model-specific fitment history and products.
1977 Subaru DL
The 1977 Subaru DL was the straightforward, value-oriented expression of Subaru's compact-car formula, aimed at buyers who wanted efficiency and utility without excess trim. Its tires mount on 13-inch wheels, and the available choices reflect the era's transition from traditional bias-ply sizing to metric radial construction.
The 1977 Subaru GL sat above the DL in presentation, giving Subaru buyers a more upscale version of the same compact platform. It also uses 13-inch wheel fitment, so tire selection comes down to whether you want a traditional bias-ply appearance or a radial construction more in keeping with regular road use.
Two products are available across one currently covered tire size for 1977 Subaru vehicles. The 155R13 radial is offered by Michelin and Dunlop in Blackwall form. Confirm your preferred size and construction before selecting, since tube status can vary within a size.
These answers cover the shared DL and GL tire sizes for 1977 Subaru, the difference between radial and bias-ply choices, 13-inch wheel requirements, Blackwall product options, and the storage and inspection habits that matter on lightly used collector cars.
Size Basics & Fitment
What tire sizes fit 1977 Subaru vehicles?
1977 Subaru DL and GL models use two tire sizes: 155R13 and 6.15-13. Both sizes fit both models, so there is no split where one size belongs only to the DL and the other only to the GL. Each size uses a 13-inch rim diameter, and the radial 155R13 has a confirmed rim-width range of 4.00 to 5.50 inches.
That means the first choice is usually construction, not model identification. Owners restoring a car to a more period-oriented presentation often start with 6.15-13 bias-ply, while owners who want a later-era compact-car feel often gravitate to 155R13 radial. Before ordering, verify the actual wheel width on the car so the selected tire matches the wheel as well as the year and model.
What does 6.15-13 mean on a 1977 Subaru tire?
On a 1977 Subaru, 6.15-13 is a numeric bias-ply tire size. The 6.15 figure is the nominal section width in inches, and the 13 is the wheel diameter in inches. Unlike a metric radial code, it does not use a millimeter width and separate aspect-ratio format.
That numbering style points to an older sizing convention and usually goes with a more traditional bias-ply driving feel. For a Subaru from 1977, that can matter if the goal is visual authenticity or an era-correct restoration impression. If your car already wears radial tires and you like the way it behaves on modern roads, compare carefully before switching constructions rather than choosing by size code alone.
Do all 1977 Subaru models use the same tire size?
Yes. The 1977 Subaru DL and 1977 Subaru GL both use the same two tire sizes: 155R13 and 6.15-13. There is no year-make split here where one core model requires a different rim diameter or a unique tire code.
That simplifies fitment research because you do not need to sort by DL versus GL before narrowing the size itself. What still changes is the ownership goal. A restored show car may call for a different construction and visual presentation than a driver that sees regular road miles, so it makes sense to decide how the car will be used before choosing between the two shared sizes.
Buying the Right Tire
Should I choose the 155R13 or the 6.15-13 for my 1977 Subaru?
For a 1977 Subaru, both sizes fit the DL and GL, but they represent two different tire traditions. The 155R13 is a radial size, while the 6.15-13 is a bias-ply size. That makes the decision less about whether the tire will go on the car and more about whether you want a later-style radial experience or a more traditional period appearance and behavior.
A car being restored for authenticity often leans toward the bias-ply option because the construction looks and feels more in step with older tire practice. A car that will spend more time on regular roads often leads owners toward a radial, especially when they want a driving feel more familiar to modern motorists. Either way, keep the 13-inch wheel diameter and actual wheel width at the center of the final check.
What sidewall styles are available for 1977 Subaru tires?
Current 155R13 options for 1977 Subaru come in Blackwall form from Michelin and Dunlop. That sidewall treatment suits the compact, practical character of late-1970s Subaru cars and avoids adding a whitewall style that would look out of place on most DL and GL examples.
Sidewall style matters because it changes the car's visual balance even when the size is correct. For a Japanese compact from 1977, Blackwall is generally the most natural visual fit unless a specific market or owner history suggests otherwise. If appearance is just as important as construction, compare sidewall details early so the tire supports the look you want rather than simply matching the diameter.
What brands make tires for 1977 Subaru vehicles?
Michelin and Dunlop currently cover 1977 Subaru in 155R13 radial form. Michelin offers the XAS-FF in 155HR13, and Dunlop offers the SP Sport Aquajet in 155R13. Both are Blackwall radial options built around the same 13-inch wheel diameter used by the DL and GL.
Brand choice on a car like a 1977 Subaru often comes down to how closely you want to mirror an imported compact's period character and which product details matter most to you. Comparing sidewall appearance, tube marking, approved wheel width, and speed rating is more useful than choosing by name alone. Once the correct size and construction are settled, brand becomes the finishing decision rather than the starting point.
Fitting & Setup
What rim width do 1977 Subaru tires require?
For 1977 Subaru vehicles using 155R13 radial tires, the confirmed rim-width range is 4.00 to 5.50 inches on a 13-inch diameter wheel. That gives DL and GL owners a clear baseline for checking whether the wheel on the car is appropriate for the radial size before mounting.
Wheel width matters because the same diameter alone does not guarantee the tire is being supported correctly. A tire fitted to a wheel outside its approved width range can affect the tread profile and the way the car feels on the road. Measure the actual wheel, especially if the car has changed hands or may have replacement wheels, and treat the wheel check as important as the size code itself.
Do 1977 Subaru tires require inner tubes?
Tube requirements on 1977 Subaru tires depend on the specific product. The Michelin 155HR13 carries a TL marking, which identifies it as tubeless, while tube status varies within the overall 155R13 radial size because not every product carries the same marking detail. That means tube use should never be assumed from size alone.
The wheel itself also plays a role, especially on older cars where rim condition and design may influence whether tubeless service is appropriate. Confirm the tire's sidewall marking and inspect the wheel before final installation decisions are made. If the car has older wheels of uncertain condition, a tire professional familiar with vintage applications can help determine whether the tire-wheel combination is suitable as configured.
Can the original 1977 Subaru wheels be used with both tire sizes?
Yes, both 155R13 and 6.15-13 use a 13-inch rim diameter, so original 1977 Subaru wheels are in the correct diameter family for either size. That shared diameter is why DL and GL owners can often compare the two sizes as construction options rather than as entirely different wheel packages.
Diameter compatibility is only the first step, though. Wheel width still needs to be confirmed against the tire you intend to use, and the radial 155R13 has a confirmed 4.00 to 5.50 inch wheel-width range. If the car has aftermarket or swapped wheels, verify the wheel dimensions directly instead of assuming that every 13-inch wheel will suit both sizes equally well.
Maintenance, Storage & Longevity
How should I store a 1977 Subaru when the tires are fitted?
A 1977 Subaru should be stored on clean, properly inflated tires in a cool, dry space away from direct sunlight, electric motors, welders, battery chargers, and other ozone sources. If the car sits for long stretches, moving it slightly from time to time helps change the contact patch. Bias-ply tires also tend to flat-spot more readily during static storage than radials.
Long-term collector storage is easiest on the tires when the car is kept out of standing moisture and off hot concrete when possible. Some owners use tire cradles or stands during extended storage, but the real goal is reducing constant stress, heat, and ozone exposure. If your Subaru alternates between display duty and occasional drives, a simple storage routine can preserve both appearance and road behavior.
How long do tires on a 1977 Subaru typically last?
On a 1977 Subaru, tire age usually matters more than tread wear because many surviving cars see limited annual mileage. A good rule is to begin evaluating tires carefully once they reach about five to seven years of age, and to treat roughly ten years as the point where replacement deserves serious consideration regardless of remaining tread depth. The DOT date code is the starting point for that timeline.
Collector cars often fool owners because the tires can still look serviceable from a distance. Rubber hardens with time, sidewalls can crack, and internal aging does not always show up as obvious wear. If the Subaru is driven only occasionally, age-based inspection becomes even more important than mileage-based thinking, especially before seasonal drives or any trip that will keep the car at sustained road speed.
How often should tires on a 1977 Subaru be inspected?
Tires on a 1977 Subaru should be checked before every drive and given a more careful inspection before any longer outing. Look for sidewall cracking, cuts, bulges, uneven tread wear, and pressure loss. If a tube-type setup is being used, include the valve stem and any signs of tube-related leakage in the inspection routine.
Frequent checks are especially important on older compact cars because they may spend weeks parked between uses. A short walk-around catches problems before they become roadside issues, and it also helps you spot changes in stance that may suggest a slow leak. Keeping a simple pressure log is useful on a lightly driven Subaru because it reveals trends that are easy to miss when the car is not used daily.
Restoration & Authenticity
What tires were originally fitted to the 1977 Subaru DL?
A 1977 Subaru DL belongs to the period when bias-ply and radial applications could overlap, especially on compact imported cars sold during the industry transition to metric radial sizing. For this year and make, both 6.15-13 bias-ply and 155R13 radial sizes are associated with the DL. That means original-equipment style research should focus on the exact market, build period, and trim history of the individual car.
If your restoration goal is factory-authentic presentation, size alone is not the whole story. Construction type and sidewall appearance can influence whether the finished car looks right for its market and era. Marque clubs, factory literature, and long-time Subaru specialists are the best places to confirm whether your particular DL would have been delivered with a bias-ply or radial tire and what visual details matter most.
Does correct tire fitment matter for showing a 1977 Subaru?
Yes, correct tire fitment matters when a 1977 Subaru is judged for originality. Size, construction type, and sidewall appearance all contribute to whether the car reads as period-correct. A radial on a car restored to an earlier factory look, or an overly modern-looking sidewall on an otherwise authentic build, can draw attention even if the tire physically fits the wheel.
The standard is not the same at every event, so the right choice depends on whether the car is being prepared for marque judging, a regional show, or a casual preservation class. Many owners choose one setup for judged events and another for regular touring, but that only works if both remain true to the wheel diameter and general proportions of the car. Event rules and Subaru club guidance should shape the final call.
How authentic is a 155R13 radial on a 1977 Subaru?
A 155R13 radial can be entirely appropriate on a 1977 Subaru because late-1970s imports were already well into the shift toward radial tire sizing. The code itself reflects that newer metric convention, and the available examples in this size are Blackwall radials, which fit the practical visual character of the DL and GL.
Authenticity still depends on the exact story of the car. A carefully preserved original may call for more exact market-specific verification than a driver-quality restoration, and some owners place equal weight on period appearance and road use. If the Subaru is headed for strict judging, confirm the expected construction and sidewall style with event-specific Subaru references before treating any radial as automatically correct.
Safety & Road Use
Are 1977 Subaru tires safe for highway driving?
1977 Subaru tires can be suitable for highway driving when the tires are in sound condition, correctly mounted, and appropriate for the way the car is used. The current 155R13 radial options carry H speed ratings, which correspond to a 130 mph ceiling. In real use, a late-1970s Subaru's brakes, suspension, alignment, and overall mechanical condition will usually matter more than the tire's top speed rating during normal highway travel.
Safety comes from the whole package rather than the speed letter alone. Fresh rubber, correct inflation, good wheel condition, and a recent inspection are more meaningful than choosing a tire with a high theoretical rating on a lightly powered vintage compact. If the car still runs older components or has been parked for long periods, treat the first longer drive as a systems check rather than assuming the tires are the only concern.
What inflation pressure should I use for 1977 Subaru tires?
Inflation pressure on a 1977 Subaru should follow the factory vehicle recommendation first, then be checked against the selected tire's own maximum-pressure and load marking where applicable. The 155R13 Dunlop example carries a maximum load of 937 pounds, but that figure should not be treated as the everyday running pressure by itself. Tire size, construction, and vehicle application all affect the proper service pressure.
The safest approach is to use the Subaru owner's manual or factory placard as the baseline for normal driving, then make sure the chosen reproduction or replacement tire is being used within its own rated limits. Never transfer a pressure assumption from one size or construction to another just because both fit a 13-inch wheel. A bias-ply 6.15-13 and a radial 155R13 should be approached as different tire types, not interchangeable pressure settings.
What should I check before taking a 1977 Subaru on a longer drive?
Before taking a 1977 Subaru on a longer drive, inspect each tire for sidewall cracking, cuts, bulges, tread separation signs, and uneven wear, then verify cold inflation pressure. Check valve stems closely, and if a tube-type setup is in use, pay attention to any slow air loss or age-related hardware issues. The spare should also be inspected rather than assumed usable.
A longer trip in a vintage Subaru calls for a broader mechanical review too, including brakes, steering, charging, and fluid condition, because tire reliability is only one part of road readiness. Small, efficient cars from this era are enjoyable travelers when prepared properly, but deferred maintenance shows up quickly at sustained speed. A careful pre-drive routine turns the tire check into part of a complete confidence check instead of a last-minute glance.
