The 1978 Mazda GLC arrived at a moment when small imported cars were gaining a strong foothold with buyers who wanted efficiency, simple packaging, and everyday usability. Its light weight and compact proportions make tire choice especially noticeable, both in appearance and in how the car feels on the road. Depending on sub-model, the 1978 Mazda GLC uses 155R13 radial, 6.15-13 bias-ply, or 175/70R13 radial tires, all on 13-inch rims. Available choices lean toward blackwall radial options from brands such as Michelin, Dunlop, and Avon. The right selection starts with the exact body style and whether the goal is period-style presentation or road-focused radial fitment.
Which Tire Size Is Right for The 1978 Mazda GLC
Three primary tire sizes apply to the 1978 Mazda GLC, and the right one depends first on the exact sub-model. All of them use a 13-inch rim, but fitment varies between radial and bias-ply construction, with the Sport 3 Dr. separated from the other covered versions by its 175/70R13 radial size. Before choosing a tire, confirm the body style and check whether the car still wears its original wheel setup.
155R13 is a Euro-metric radial size in which 155 refers to nominal section width in millimeters, R identifies radial construction, and 13 is the wheel diameter in inches. On the 1978 Mazda GLC, this size suits several sub-models and gives a distinctly late-1970s imported-car fitment pattern. Available choices include Michelin and Dunlop blackwall radials in series such as Michelin XAS-FF and SP Sport Aquajet. This size is a strong place to start if the car is one of the covered non-Sport versions and the goal is to stay with a traditional small-car radial format.
6.15-13 is a numeric bias-ply size, with 6.15 indicating nominal section width in inches and 13 identifying the rim diameter. For the 1978 Mazda GLC, this size represents the bias-ply fitment used on several sub-models rather than the Sport 3 Dr. radial setup. Bias-ply construction matters here mainly for owners pursuing a more traditional period-style look and feel on a 13-inch wheel. This size deserves a close look when maintaining an earlier-style presentation, but wheel condition and overall vehicle setup should still be checked before staying with or returning to bias-ply construction.
175/70R13 is a metric radial size in which 175 gives the nominal section width in millimeters, 70 is the aspect ratio, R denotes radial construction, and 13 is the rim diameter. On the 1978 Mazda GLC, this size is tied to the Sport 3 Dr., making it a sub-model-specific fitment rather than a universal GLC choice. The available product in this size is an Avon CR6ZZ blackwall radial, adding a more specialized radial option within the correct diameter. It should be evaluated when the car is a Sport 3 Dr. and the wheel width and clearance still match that configuration.
Sub-model fitment matters on the 1978 Mazda GLC because most covered versions share two traditional size paths, while the Sport 3 Dr. uses a different radial size. Checking the exact body style is the quickest way to avoid choosing a tire that matches the wheel diameter but not the intended fitment.
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1978 Mazda GLC DLX & Sedan 3 Dr.
The 1978 Mazda GLC DLX & Sedan 3 Dr. uses either 155R13 radial or 6.15-13 bias-ply tires on 13-inch rims. That gives the owner a clear choice between a more traditional bias-ply presentation and a radial format that better reflects later-1970s small-car tire construction.
The 1978 Mazda GLC DLX 5 Dr. follows the same two-size pattern as other non-Sport versions, using either 155R13 radial or 6.15-13 bias-ply. Tire selection here comes down to preserving period character versus choosing a radial option that fits the car's established 13-inch wheel format.
The 1978 Mazda GLC Sport 3 Dr. uses 175/70R13 radial tires rather than the 155R13 and 6.15-13 sizes found on other covered sub-models. That makes wheel-width confirmation especially important before purchase, particularly if the car has seen aftermarket wheel or suspension changes over the years.
The 1978 Mazda GLC Wagon uses either 155R13 radial or 6.15-13 bias-ply tires on a 13-inch rim. Owners can focus their decision on construction type and period-style appearance, then compare available radial products if the car is intended for regular road use.
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 Mazda GLC Tires for Sale
Available 13-inch tire choices for the 1978 Mazda GLC center on blackwall radials from Michelin, Dunlop, and Avon. The product grid is most useful for comparing size-specific series, construction, and rim-width compatibility between 155R13 and 175/70R13 applications.
Common 1978 Mazda GLC tire questions usually come down to sub-model-specific sizing, 13-inch rim fitment, radial versus bias-ply choices, and how to choose a tire that suits restoration goals or actual road use.
Tire Size & Fitment
What tire size fits a 1978 Mazda GLC?
The 1978 Mazda GLC uses three primary tire sizes across its covered sub-models: 155R13 radial, 6.15-13 bias-ply, and 175/70R13 radial. Most non-Sport versions use either 155R13 or 6.15-13, while the Sport 3 Dr. uses 175/70R13.
The main step is matching the tire to the exact sub-model before comparing brands or tire series. Every size here fits a 13-inch rim, but that does not make them interchangeable across all GLC configurations, especially if the car has different wheels than it originally carried.
What size rim does a 1978 Mazda GLC use?
The covered tire fitments for the 1978 Mazda GLC all use a 13-inch rim diameter. That applies whether the car is using 155R13 radial, 6.15-13 bias-ply, or 175/70R13 radial tires.
Rim diameter is only the first check, because wheel width still affects which tire is appropriate. A GLC with replacement wheels can still measure 13 inches in diameter while using a width or offset that changes how a particular radial tire sits and clears the body or suspension.
Why does the 1978 Mazda GLC have more than one tire size?
The 1978 Mazda GLC has more than one tire size because fitment varies by sub-model and construction type. The DLX & Sedan 3 Dr., DLX 5 Dr., and Wagon can use either 155R13 radial or 6.15-13 bias-ply, while the Sport 3 Dr. uses 175/70R13 radial.
That difference means tire selection is not just about finding a 13-inch tire with a similar look. Owners should verify the exact body style first, then confirm the current wheel setup so the chosen tire matches the car's intended fitment and not simply the rim diameter.
Choosing the Right Tire
What should I consider when choosing a tire for a 1978 Mazda GLC?
Start with the exact sub-model, since the 1978 Mazda GLC can use 155R13 radial, 6.15-13 bias-ply, or 175/70R13 radial depending on configuration. After size is confirmed, the next decision is whether the car's purpose calls for period-style bias-ply presentation or a radial tire that suits regular driving.
Brand, tire series, and wheel compatibility become more important once the correct size is locked in. A collector car kept close to its original character may lean one way, while a road-driven GLC with known wheel dimensions may justify a different choice within the proper size.
What sidewall styles are available for 1978 Mazda GLC tires?
The available 1978 Mazda GLC products in the covered radial sizes use blackwall sidewalls. That includes the Michelin and Dunlop options in 155R13 as well as the Avon option in 175/70R13.
Blackwall construction gives the car a clean, understated late-1970s small-car appearance, but sidewall style should still come after correct fitment. Once the proper size and sub-model are confirmed, the real comparison becomes tire series, construction, and wheel-width suitability rather than decorative sidewall variation.
What brands offer tires for the 1978 Mazda GLC?
Michelin, Dunlop, and Avon offer applicable radial tires for the 1978 Mazda GLC. Michelin and Dunlop appear in the 155R13 fitment, while Avon covers the 175/70R13 size used on the Sport 3 Dr.
Brand choice should be considered within the correct tire size rather than across the full GLC range. A useful comparison includes the tire series offered in that size, the wheel-width requirement where stated, and whether the tire suits a restoration-oriented car or one expected to see more frequent road use.
Restoration & Appearance
Which tire should I choose for a period-style 1978 Mazda GLC?
A period-style 1978 Mazda GLC starts with the correct size for the exact sub-model, then with the construction that best matches the look you want. On the non-Sport versions, 6.15-13 bias-ply presents the most traditional visual and structural character, while 155R13 keeps the proper small-car radial format.
Appearance should be balanced against how the car will actually be used. A GLC shown as a preservation or restoration piece may justify one path, while a car driven more often may point toward a radial choice in the correct size after the wheel setup and overall fitment are checked.
How does tire construction affect the appearance of a restored 1978 Mazda GLC?
Tire construction changes the visual stance of a restored 1978 Mazda GLC as much as it changes the driving character. A 6.15-13 bias-ply gives the car a more traditional period presentation, while 155R13 or 175/70R13 radial fitments reflect the later-1970s move toward compact imported-car radial tires.
That choice matters because a restoration can aim for different eras of ownership and use, not just one interpretation. Buyers focused on exact originality should compare the car's history and supporting reference material, then choose a construction and size that align with both the look and the current wheel setup.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1978 Mazda GLC?
Yes, modifications can affect tire fitment on a 1978 Mazda GLC even when the replacement tire has the correct nominal size. Aftermarket 13-inch wheels, different wheel widths, altered offsets, suspension lowering, or body changes can all influence clearance and how the tire sits on the car.
That is especially important here because the GLC already has sub-model-specific sizing differences. A smart check includes measuring the actual wheel, confirming the body style, and looking for steering or fender interference before changing between 155R13, 6.15-13, or 175/70R13 fitments.
What should I inspect before driving a 1978 Mazda GLC on new tires?
Before driving a 1978 Mazda GLC on new tires, inspect the wheels for damage, confirm that the rim diameter and width suit the chosen tire, and make sure the tires are mounted in the correct size for the sub-model. Basic checks should also include inflation pressure, valve stems, and visible clearance around the suspension and body.
Collector cars often sit for long periods, so it is wise to recheck wheel fasteners, look for rubbing during low-speed steering movement, and monitor air retention after installation. A brief test drive followed by another inspection can catch small fitment or clearance issues before they become larger problems.
How should tires on a collector 1978 Mazda GLC be maintained?
Tires on a collector 1978 Mazda GLC should be kept properly inflated, inspected regularly for cracking, bulges, cuts, or uneven wear, and checked for air loss even when the car is driven infrequently. Low-mileage collector use does not prevent aging, especially on cars stored for long periods.
Storage conditions matter almost as much as mileage. Keeping the car away from prolonged sunlight, excess moisture, and ozone sources helps protect the sidewalls, while periodic movement reduces long-term flat spotting. Any tire that shows age-related deterioration deserves attention before the car returns to normal road use.
