The 1980 Oldsmobile Starfire came from the final stretch of GM’s compact rear-wheel-drive hatchback era, giving the model a distinct late-classic mix of sporty styling and everyday drivability. For owners keeping one on the road today, tire choice affects both the car’s stance and how faithfully it reflects its period. The 1980 Oldsmobile Starfire uses 13-inch fitments that include A78-13 and B78-13 bias-ply sizes as well as BR78-13 radial construction. That leaves room to balance traditional bias-ply appearance against radial-style driving priorities. The key is confirming the exact tire size and wheel setup on the car before choosing a replacement.
Which Tire Size Is Right for The 1980 Oldsmobile Starfire
The 1980 Oldsmobile Starfire uses three primary tire sizes, all on 13-inch rims: A78-13, B78-13, and BR78-13. Because these sizes span both bias-ply and radial construction, the first step is confirming which size and tire type your specific Starfire is already using. Once that is settled, the real decision becomes whether to stay with the existing construction and how closely the replacement should match your appearance and driving goals.
A78-13 is a vintage alphanumeric bias-ply size in which the letter and series identify the tire’s size class and profile family, while 13 designates the wheel diameter in inches. On a 1980 Oldsmobile Starfire, it represents a traditional bias-ply fitment with the period-style look and construction many late-1970s and early-1980s compact cars carried. Because this size also has modern radial equivalents available, it is often the starting point for owners deciding between preserving a more original-style presentation and considering an alternate road-use approach. Wheel width and overall vehicle setup should still be checked before changing tire type.
B78-13 is another vintage alphanumeric bias-ply size, using the same basic naming format with the final 13 indicating a 13-inch rim. For the 1980 Oldsmobile Starfire, this size keeps the car in a traditional bias-ply category while offering a different size class than A78-13. It is also the bias-ply size in this fitment group with the broadest radial-equivalent path, including metric, P-metric, and bias-look radial alternatives. That makes it especially important to confirm the tire already on the car and to compare wheel dimensions and clearance before moving in a different direction.
BR78-13 is an alphanumeric radial size, with the R identifying radial construction and the final 13 indicating the wheel diameter. On the 1980 Oldsmobile Starfire, this size points to a primary radial fitment rather than a bias-ply replacement choice. It is the most familiar option for owners who want to stay with the construction already associated with a radial-equipped Starfire and avoid mixing size systems unnecessarily. Before selecting BR78-13, it is still wise to verify the wheel size on the car and make sure the existing tire setup has not been changed over the years.
Fitment is straightforward across the covered 1980 Oldsmobile Starfire sub-models, because Base, Firenza, GT, and SX all use the same three 13-inch tire-size choices. Even with that shared fitment pattern, checking the exact size already on the car still matters before choosing between bias-ply and radial construction.
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1980 Oldsmobile Starfire Base
The 1980 Oldsmobile Starfire Base uses the same A78-13, B78-13, and BR78-13 fitment group found across the rest of the covered lineup. Tire selection comes down to confirming which size and construction are on the car now, then deciding whether to keep a period-style bias-ply setup or stay with radial construction.
The 1980 Oldsmobile Starfire Firenza shares the same three 13-inch tire sizes: A78-13, B78-13, and BR78-13. That keeps fitment simple at the sub-model level, but it still leaves an important choice between traditional bias-ply sizing and a primary radial fitment depending on the wheel and tire combination currently in use.
The 1980 Oldsmobile Starfire GT follows the same tire pattern as the other covered sub-models, using A78-13, B78-13, and BR78-13 on 13-inch rims. The practical step is to verify the exact tire size mounted on the car, then choose a replacement that matches the intended appearance, construction type, and wheel setup.
The 1980 Oldsmobile Starfire SX uses the same 13-inch fitment family as the rest of the model range, including A78-13, B78-13, and BR78-13. For replacement planning, that means the main question is not sub-model variation but whether the car is currently set up with a bias-ply or radial tire and whether that setup should remain unchanged.
Bias-Ply to Radial Tire Conversion for the 1980 Oldsmobile Starfire
A78-13 and B78-13 both have radial-equivalent choices for the 1980 Oldsmobile Starfire. For A78-13, the available alternatives are 165R13 as an 80-series metric radial, P165/75R13 as a 75-series P-metric radial, and P175/70R13 as a 70-series P-metric radial. For B78-13, the choices are 175R13, P175/75R13, P185/70R13, and 650R13 as a bias-look radial. Recommended rim widths are 4-5 inches for A78-13 and 4-6 inches for B78-13, and any conversion should be checked against wheel size and vehicle clearance.
Modern Radial Equivalents
165R13
Equivalent 80-series Metric Radial (A78-13)
P165/75R13
Equivalent P-metric 75-series Radial (A78-13)
P175/70R13
Equivalent P-metric 70-series Radial (A78-13)
175R13
Equivalent 80-series Metric Radial (B78-13)
P175/75R13
Equivalent P-metric 75-series Radial (B78-13)
P185/70R13
Equivalent P-metric 70-series Radial (B78-13)
650R13
Bias-look Radial Equivalent (B78-13)
Important Considerations When Replacing Bias Ply With Radial
Compare overall diameter and section width carefully to ensure proper fit.
Verify recommended rim range (4-6 in) and load needs match your vehicle specifications.
Check fender clearance, steering clearance, and stance before installation.
Consider suspension condition and intended road use when choosing equivalents.
Important Fitment Notes
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.
Frequently Asked Questions
These FAQs focus on the exact tire sizes used on the 1980 Oldsmobile Starfire, the difference between its bias-ply and radial fitments, and what to verify before choosing a replacement for road use or a restoration-minded setup.
Tire Size & Fitment
What tire size fits a 1980 Oldsmobile Starfire?
The 1980 Oldsmobile Starfire uses A78-13 and B78-13 in bias-ply construction, along with BR78-13 in radial construction. All three sizes are built for 13-inch rims, so the Starfire’s fitment question is less about wheel diameter and more about confirming which of those three sizes is actually on the car.
Many surviving Starfires have been maintained, restored, or modified over time, so the safest approach is to check the sidewall of the existing tires and confirm the wheel itself before ordering replacements. Once the current size is verified, the next decision is whether to remain with the same construction type or evaluate one of the available radial alternatives for the bias-ply sizes.
What size rim does a 1980 Oldsmobile Starfire use?
The tire sizes used on the 1980 Oldsmobile Starfire are all built around a 13-inch rim diameter. That applies to A78-13, B78-13, and BR78-13, so the wheel diameter remains consistent even though the vehicle can use more than one tire size and more than one tire construction.
Rim diameter is only one part of the fitment picture, so it is still smart to check the actual wheel on the car before selecting tires. Width and any aftermarket wheel changes can influence which tire size or equivalent works best, especially if a Starfire has been updated from a bias-ply setup to a radial or has had its wheels changed over the years.
Do all 1980 Oldsmobile Starfire sub-models use the same tire size?
Base, Firenza, GT, and SX versions of the 1980 Oldsmobile Starfire share the same fitment group: A78-13, B78-13, and BR78-13. That means the sub-model itself does not force a different tire-size family within the covered lineup, and each stays on a 13-inch rim.
Even with that shared fitment pattern, it is still important to identify the exact size already mounted on the car. A Starfire equipped with BR78-13 radial tires should not be treated the same as one currently wearing A78-13 or B78-13 bias-ply tires, especially if the goal is to preserve the car’s period appearance or keep wheel and clearance relationships consistent.
Bias-Ply & Radial Options
Is A78-13 a bias-ply or radial tire for the 1980 Oldsmobile Starfire?
A78-13 is a bias-ply tire size for the 1980 Oldsmobile Starfire. It uses the vintage alphanumeric bias-ply sizing system, so it belongs to the traditional construction side of the Starfire’s fitment choices rather than the radial side represented by BR78-13.
That distinction matters because staying with A78-13 keeps the car in its original size format and construction style, while moving away from it changes more than just the numbers on the sidewall. Owners considering a radial alternative should compare wheel width, tire dimensions, and clearance carefully instead of assuming that any radial with a similar rim diameter will behave the same on the car.
What radial tire sizes are equivalent to A78-13 and B78-13?
A78-13 can be compared with 165R13 as an 80-series metric radial, P165/75R13 as a 75-series P-metric radial, and P175/70R13 as a 70-series P-metric radial. B78-13 has 175R13, P175/75R13, and P185/70R13 as radial equivalents, plus 650R13 as a bias-look radial equivalent.
Those choices give a Starfire owner several ways to move from a bias-ply size into a radial format, but they should be treated as alternatives rather than automatic replacements. The recommended rim-width range is 4-5 inches for A78-13 equivalents and 4-6 inches for B78-13 equivalents, so wheel width, overall vehicle setup, and clearance should all be verified before making a change.
Should I use bias-ply or radial tires on a 1980 Oldsmobile Starfire?
The right choice depends on how the 1980 Oldsmobile Starfire is currently equipped and what the owner wants from the car. A78-13 and B78-13 keep the Starfire in bias-ply sizing, while BR78-13 is a primary radial fitment and the bias-ply sizes also have radial-equivalent alternatives.
Bias-ply tires are often chosen for a more traditional look, while radial choices are commonly considered by owners focused on modern road use. Either direction starts with confirming the existing tire and wheel setup, because construction changes can affect how the car sits and how the tire relates to the wheel, fender opening, and overall appearance.
Choosing the Right Tire
What should I consider when choosing a 1980 Oldsmobile Starfire tire?
Start by confirming whether the car uses A78-13, B78-13, or BR78-13, because the 1980 Oldsmobile Starfire spans both bias-ply and radial construction. That makes size verification more important than simply ordering by year and model, especially on a car that may have been restored or updated over time.
After the size is confirmed, think about how the car will be used and how closely the replacement should follow a period-style presentation. A buyer keeping a Starfire visually rooted in its era may stay with the same bias-ply format, while a buyer evaluating a radial alternative should also compare wheel width, tire proportions, and clearance before making the switch.
How do I choose between the available A78-13 and B78-13 tires for a 1980 Oldsmobile Starfire?
The first step is making sure the car actually uses A78-13 or B78-13, because those two sizes are not interchangeable by assumption just because both are bias-ply and both fit 13-inch rims. Once the size is verified, the main comparison becomes whether to stay with the existing bias-ply format or evaluate one of the radial-equivalent paths tied to that exact size.
A78-13 and B78-13 have different radial-equivalent families and different recommended rim-width ranges, so the details of the wheel matter. Owners should look at the current tire size, the wheel dimensions, and the intended appearance of the car before choosing, particularly if the Starfire is being maintained as a period-style driver rather than simply fitted with any 13-inch tire.
What rim-width specifications should I compare when choosing 1980 Oldsmobile Starfire tires?
Rim width becomes especially important when a 1980 Oldsmobile Starfire owner is comparing radial equivalents for the bias-ply sizes. A78-13 equivalents are associated with a 4-5 inch recommended rim-width range, while B78-13 equivalents use a 4-6 inch recommended range.
That does not mean every wheel on every Starfire automatically falls inside those ranges, particularly on cars that may have had wheel changes over the decades. Checking the actual wheel width helps narrow the right equivalent family and reduces the chance of selecting a tire that creates avoidable fitment, appearance, or clearance issues once it is mounted on the car.
Restoration & Appearance
Which tire should I choose for a period-style 1980 Oldsmobile Starfire?
For a period-style 1980 Oldsmobile Starfire, the natural starting point is the tire size and construction already associated with the car: A78-13 or B78-13 in bias-ply form, or BR78-13 if the car is set up around a primary radial fitment. Keeping the same size format usually preserves the most authentic overall presentation.
Owners focused on exact originality should still confirm their particular car’s history through marque references, build documentation, or other authoritative sources before making a final choice. For many restoration-oriented drivers, the practical decision is whether visual authenticity matters more than exploring a radial alternative that changes the tire format while keeping the car on a 13-inch wheel.
How does tire construction affect the appearance of a restored 1980 Oldsmobile Starfire?
Tire construction changes more than ride feel on a restored 1980 Oldsmobile Starfire; it also affects the car’s visual character. Bias-ply sizes such as A78-13 and B78-13 maintain the vintage alphanumeric format that suits a late-1970s to early-1980s compact, while BR78-13 and modern radial equivalents introduce a more radial-era presentation.
That difference can matter on a car where the stance and sidewall style are part of the restoration story. A buyer who wants the Starfire to read as a period-style car may prefer staying with the original-format size family, while someone building a regular driver may decide that a radial alternative is acceptable after verifying wheel compatibility and overall fit.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1980 Oldsmobile Starfire?
Yes, modifications can change tire fitment on a 1980 Oldsmobile Starfire even when the replacement tire matches one of the recognized 13-inch sizes. Aftermarket wheels, altered wheel width, suspension changes, ride-height adjustments, or body modifications can all affect how A78-13, B78-13, BR78-13, or a radial equivalent sits in the car.
A Starfire that no longer has its original wheel and suspension setup deserves a closer check before any new tires are mounted. Measuring the wheel, verifying steering and fender clearance, and comparing the current tire’s relationship to the car can prevent surprises, especially when converting from a bias-ply size to one of the metric or P-metric radial alternatives.
What should I inspect before driving a 1980 Oldsmobile Starfire on new tires?
Before driving a 1980 Oldsmobile Starfire on new tires, inspect the wheels for the correct 13-inch diameter and confirm the wheel width suits the tire being used. It is also smart to check that the tires clear the fenders and steering components properly and that the car does not have worn suspension parts that could affect tracking or clearance.
Collector-era cars often spend long periods parked, so a fresh tire installation is a good time to look over the whole contact patch area. Check inflation, lug torque, valve stems, visible alignment behavior, and any signs of rubbing during slow turns, then recheck the setup after the first short drive to make sure the Starfire is settling in as expected.
How should tires on a collector 1980 Oldsmobile Starfire be maintained?
Tires on a collector 1980 Oldsmobile Starfire should be inspected regularly even if the car sees limited mileage. Look for cracking, bulges, cuts, irregular wear, and slow air loss, and keep inflation consistent so the tire maintains its intended shape whether the car uses bias-ply sizes or a radial setup.
Storage conditions matter almost as much as mileage on a low-use Starfire. Keeping the car away from prolonged sunlight, excess heat, moisture, and ozone sources can help preserve the tires, and moving the vehicle periodically can reduce flat-spotting concerns. Before any longer drive, a careful visual inspection and pressure check are worthwhile regardless of tread depth.
