The 1977 Buick Regal sits squarely in the personal-luxury coupe era, when midsize American cars balanced formal styling, comfort, and just enough performance character to keep enthusiasts interested. For many owners today, that means tire choice is part fitment decision and part appearance decision. The 1977 Buick Regal uses vintage alphanumeric radial sizes, with 14-inch fitments on 6-cylinder cars and 15-inch fitments on 8-cylinder cars. That split makes wheel diameter and engine-based sub-model especially important, and GR70-15 buyers also have period-style bias-look radial choices with either pin white stripe or raised white letter sidewall treatments. The right selection depends on the Regal’s exact configuration and the presentation you want on the car.
Which Tire Size Is Right for The 1977 Buick Regal
Four tire sizes apply to the 1977 Buick Regal, and the correct one depends first on the sub-model and wheel diameter. The 6-cylinder Regal uses 14-inch radial fitments, while the 8-cylinder Regal uses 15-inch radial fitments. Before choosing a tire, confirm whether the car is a 6-cylinder or 8-cylinder model and verify the wheels currently on the car, especially if it has been changed from its original-style setup.
FR78-14 is a vintage alphanumeric radial size. In this format, the letter identifies the tire’s size class, the R indicates radial construction, the series number places it within a traditional profile family, and the final number is the 14-inch rim diameter. On a 1977 Buick Regal, this size belongs with 14-inch wheel applications rather than the 15-inch setups used elsewhere in the range. It suits owners who need to keep a proper radial fitment on a 14-inch Regal and who want to begin the buying process by matching the car’s wheel diameter and exact sub-model.
GR78-14 is also a vintage alphanumeric radial size, using the same older sizing convention but in a different size class from FR78-14. The R marks it as radial construction, and the 14 at the end identifies a 14-inch rim. For the 1977 Buick Regal, this size is part of the 14-inch fitment group used on 6-cylinder cars, so it should not be treated as interchangeable with the Regal’s 15-inch tire options. It is the size to evaluate when the car keeps a 14-inch wheel package and the goal is to stay within the proper Regal fitment range.
GR70-15 is a vintage alphanumeric radial size for a 15-inch rim, with the R indicating radial construction and the 70-series profile setting it apart from GR78-15. On the 1977 Buick Regal, this size belongs to 8-cylinder applications and carries the most visible product variety, including Goodyear offerings in GM Custom Tread, Steelgard, and Custom Wide Tread series. Sidewall choices include pin white stripe and raised white letter, which gives this size added appeal for buyers balancing period-style appearance with an authentic late-1970s road-car look.
GR78-15 is another vintage alphanumeric radial size, sharing the 15-inch rim diameter of GR70-15 but using a different profile family within the same older sizing system. The letter and series work together to define the tire’s size class, while the R confirms radial construction. For a 1977 Buick Regal, this size is associated with 8-cylinder cars and should be chosen only after confirming the wheel diameter and the vehicle’s actual setup. It is the right fitment path for owners keeping the Regal within its 15-inch radial range without assuming every 15-inch option is the same.
Sub-model fitment matters on the 1977 Buick Regal because tire size splits between the 6-cylinder and 8-cylinder cars. Checking the exact sub-model first helps narrow the search to the correct rim diameter and keeps 14-inch and 15-inch applications from being mixed.
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1977 Buick Regal 6 Cyl.
The 1977 Buick Regal 6 Cyl. uses 14-inch radial fitments, with FR78-14 and GR78-14 applying to this sub-model. That makes wheel confirmation especially important before ordering, particularly on cars that may have been updated with different wheels over the years.
The 1977 Buick Regal 8 Cyl. uses 15-inch radial fitments, with GR70-15 and GR78-15 associated with this sub-model. Buyers looking at this Regal configuration should confirm which 15-inch size the car needs, then compare sidewall style and tire-series choices where product variety is available.
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 1977 Buick Regal Tires for Sale
Available product choice centers on GR70-15, where Goodyear offers several bias-look radial options across GM Custom Tread, Steelgard, and Custom Wide Tread series. Buyers can compare pin white stripe and raised white letter sidewalls along with rim-width specifications for different 15-inch Regal presentations.
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Goodyear Tires
Goodyear GM Custom Tread Pin White Stripe | GR70-15
Common 1977 Buick Regal tire questions usually come down to sub-model fitment, 14-inch versus 15-inch wheel setups, vintage radial sizing, and how to choose the right sidewall style for the car’s intended appearance and road use.
Tire Size & Fitment
What tire size fits a 1977 Buick Regal?
The 1977 Buick Regal uses four vintage alphanumeric radial sizes: FR78-14, GR78-14, GR70-15, and GR78-15. The 6-cylinder Regal uses the 14-inch sizes, while the 8-cylinder Regal uses the 15-inch sizes, so there is not one universal tire size for every 1977 Regal.
The practical first step is confirming the car’s exact sub-model and the wheels currently on it. Many collector cars have had wheel changes over the years, and that matters here because the Regal uses both 14-inch and 15-inch applications. Matching the size to the wheel diameter and vehicle configuration will narrow the search to the proper fitment family.
What size rim does a 1977 Buick Regal use?
A 1977 Buick Regal uses either a 14-inch or 15-inch rim, depending on the sub-model and tire size. FR78-14 and GR78-14 are 14-inch fitments, while GR70-15 and GR78-15 are 15-inch fitments. The final number in each vintage size code corresponds to the wheel diameter in inches.
That means the wheel diameter should be confirmed before any tire is selected. A Regal that now wears aftermarket wheels, replacement rally wheels, or wheels from another GM model may no longer match the original-style configuration. Checking the wheel itself prevents a common mistake, especially when two different diameters apply within the same year and model.
Do all 1977 Buick Regal sub-models use the same tire size?
No. The 1977 Buick Regal 6 Cyl. uses 14-inch radial sizes, while the 1977 Buick Regal 8 Cyl. uses 15-inch radial sizes. That split means sub-model identification is an important part of tire selection, even before comparing brands, sidewall treatments, or tire series.
Owners should treat the sub-model as a fitment checkpoint, not just a trim description. Once the correct sub-model is established, the search becomes much more straightforward because it separates the Regal into two wheel-diameter groups. After that, the focus can shift to the actual size mounted on the car and any appearance goals for the finished tire choice.
Choosing the Right Tire
What should I consider when choosing a GR70-15 tire for a 1977 Buick Regal?
Start by confirming that GR70-15 is the correct 15-inch size for the specific 1977 Buick Regal in front of you. It is used on 8-cylinder applications, and available choices in this size include Goodyear bias-look radial designs with different sidewall presentations and tire series.
Once size is confirmed, compare the visual character of the tire as closely as the fitment details. Pin white stripe and raised white letter sidewalls create different late-1970s looks, and rim-width specifications vary slightly across products. A Regal aimed at restoration-style appearance may call for one presentation, while a driver-focused car may simply need the option that best suits its wheel setup.
What sidewall styles are available for 1977 Buick Regal tires?
For the 1977 Buick Regal product selection shown in GR70-15, the available sidewall styles are Pin-White-Stripe and RWL, which is raised white letter. Both appear on Goodyear bias-look radial offerings, giving 15-inch Regal owners a choice between a more formal stripe treatment and a sportier lettered presentation.
Sidewall style changes the car’s visual tone more than many buyers expect, especially on a personal-luxury coupe from this era. The right choice depends on how the Regal is being presented rather than on size alone. It still makes sense to verify the underlying fitment first, since appearance options only matter after the wheel diameter and tire size are correct.
What tire series are available for the 1977 Buick Regal?
In GR70-15, the 1977 Buick Regal has access to Goodyear tire series including GM Custom Tread, Steelgard, and Custom Wide Tread. These series give buyers different period-style presentations within the same general size family, rather than changing the Regal into a different fitment category.
Series choice is most useful once the basic decisions are settled: correct sub-model, correct wheel diameter, and correct tire size. From there, the comparison becomes more about the look and character of the tire, along with sidewall style and wheel compatibility. That approach helps avoid choosing a tire by appearance first and solving fitment questions later.
Restoration & Appearance
Which tire should I choose for a period-style 1977 Buick Regal?
A period-style 1977 Buick Regal tire choice starts with the correct vintage alphanumeric radial size for the car’s exact sub-model and wheel diameter. For 15-inch 8-cylinder applications, GR70-15 opens the door to Goodyear bias-look radial options that preserve a traditional late-1970s visual character while staying within the proper size family.
Appearance should be matched to the car’s intended presentation rather than assumed from the model name alone. A formal street Regal may look more at home with a pin white stripe, while another build may suit raised white letters better. When exact originality matters, it is worth checking marque-specific reference material before settling on a sidewall treatment.
How does tire construction affect the appearance of a restored 1977 Buick Regal?
Construction affects both the visual impression and the overall character of a restored 1977 Buick Regal. The primary fitments for this Regal are radial sizes, and some available GR70-15 products use bias-look radial construction, which is designed to preserve a more traditional profile and sidewall presentation than a modern-looking replacement tire.
That matters because a restored car is judged as much by stance and sidewall style as by paint or trim. A tire that keeps the right era feel can support the Regal’s original design language without claiming exact factory originality. It is still important to confirm the wheel setup and the chosen size before treating appearance as the deciding factor.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1977 Buick Regal?
Yes. Modifications can change tire fitment on a 1977 Buick Regal, especially because this model already spans both 14-inch and 15-inch wheel applications. Aftermarket wheels, changes in wheel width, suspension alterations, or body modifications can all affect whether the intended tire size remains suitable for the car.
A Regal with non-original wheels should be checked carefully before any tire is selected, even when the size seems close to one of the factory-style fitments. Wheel diameter is only the first checkpoint. Measuring the actual wheel, confirming width, and checking clearance at the fender and steering range will help prevent fitment surprises once the new tires are mounted.
What should I inspect before driving a 1977 Buick Regal on new tires?
Before driving a 1977 Buick Regal on new tires, inspect the wheels, valve stems, lug hardware, and the general condition of the suspension and steering components. The car should also be checked for any signs of rubbing or interference, especially if the Regal has been sitting for long periods or no longer carries its original-style wheel setup.
Tire pressure should be set correctly for the installed tires, and the tires themselves should be looked over for proper seating and even clearance. A short initial drive is a smart way to confirm that the car tracks properly and that nothing contacts the body or chassis. Any vibration or rubbing should be addressed before normal road use.
How should tires on a collector 1977 Buick Regal be maintained?
Tires on a collector 1977 Buick Regal should be maintained with regular pressure checks, visual inspections, and attention to age-related condition. Even a car driven only occasionally can develop cracking, flat spotting, air loss, or sidewall damage if it sits too long or is stored in poor conditions.
Storage plays a major role in tire life on a collector car. Keeping the Regal away from prolonged sunlight, heat, moisture, and ozone sources can help preserve the tires between drives. It also helps to inspect tread and sidewalls before each outing, since a low-mileage car may spend more time aging in the garage than wearing its tires on the road.
