The 1979 Oldsmobile Starfire came at the end of the small rear-wheel-drive hatchback era, giving buyers a compact Oldsmobile with distinctly late-1970s American styling and a wider range of personality depending on engine choice. That matters at the tire level, because this exact model year uses four different 13-inch tire sizes across its L-4, V6, and V8 versions, with both bias-ply and radial fitments in the mix. Buyers can be sorting through traditional alphanumeric bias-ply sizes such as A78-13 and B78-13, or radial sizes such as BR78-13 and BR70-13. The right choice starts with identifying the exact sub-model, then deciding whether originality, appearance, and road-use goals point toward bias-ply fitment or a radial-based setup.
Which Tire Size Is Right for The 1979 Oldsmobile Starfire
The 1979 Oldsmobile Starfire uses four primary tire sizes, all built around a 13-inch rim, but the correct one depends on the exact sub-model and whether the car was fitted with bias-ply or radial construction. Before choosing a tire, confirm whether the Starfire is an L-4, V6, or V8, because that determines which size family applies and whether a bias-ply fitment or a radial fitment is the right starting point.
A78-13 is a vintage alphanumeric bias-ply size in which the letter marks the tire's size class, the 78 designates its profile family, and the 13 indicates a 13-inch rim. On the 1979 Oldsmobile Starfire, this size belongs to the bias-ply side of the fitment picture and is tied to specific L-4 applications rather than the full model range. Its traditional sizing format makes it especially relevant for owners who want a period-style look and bias-ply character. It is also one of the sizes that can be compared against modern radial equivalents when evaluating a construction change.
B78-13 uses the same vintage alphanumeric bias-ply system, with the letter identifying the size class, the 78 indicating the profile family, and the 13 showing the required rim diameter. This size appears on certain 1979 Oldsmobile Starfire L-4 and V6 applications, so it is important not to assume it belongs on every Starfire. B78-13 is useful for buyers pursuing a more traditional bias-ply presentation, and it also carries the broadest equivalent-size path on this page. That makes it a key fitment to evaluate carefully if originality and modern road manners are both part of the decision.
BR78-13 is an alphanumeric radial size, with the R built into the designation to indicate radial construction, while the final 13 still refers to a 13-inch rim. On the 1979 Oldsmobile Starfire, this size is associated with V6 fitment and represents a different construction approach than the bias-ply options used elsewhere in the lineup. Its format reflects the transitional late-1970s period when some compact American cars could be found with either traditional or modernized tire construction depending on configuration. Choosing BR78-13 starts with confirming the exact sub-model and then matching that size to the car's present wheel setup.
BR70-13 is also an alphanumeric radial, but its 70-series profile family separates it from the taller 78-series sizes used on other 1979 Oldsmobile Starfire versions. This size is tied to the V8 application, so it serves a specific role within the model range rather than acting as a shared fitment. Because it is already a radial primary size, the selection decision here centers less on conversion and more on staying with the proper size, construction, and overall presentation. Owners should confirm that the car still has the correct 13-inch wheel setup before moving ahead with a replacement.
Sub-model fitment matters on the 1979 Oldsmobile Starfire because the covered versions do not all share the same tire size or even the same construction type. Identifying whether the car is an L-4, V6, or V8 is the first step before comparing bias-ply choices, radial fitments, or modern radial equivalents.
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1979 Oldsmobile Starfire L-4
The 1979 Oldsmobile Starfire L-4 uses bias-ply sizing, with A78-13 and B78-13 both appearing within its fitment range. That makes size confirmation especially important before selecting a period-style replacement or considering one of the radial equivalent routes associated with those bias-ply sizes.
The 1979 Oldsmobile Starfire V6 sits at the crossover point in this lineup, using either B78-13 bias-ply or BR78-13 radial fitment depending on configuration. Tire selection here starts with confirming which construction and size the car is actually wearing, then matching that to the wheel setup and intended appearance.
The 1979 Oldsmobile Starfire V8 uses BR70-13 radial fitment, making it the most straightforward sub-model in this group from a size standpoint. The main decision is staying with the correct radial size on the proper 13-inch wheel rather than sorting through multiple primary fitment paths.
Bias-Ply to Radial Tire Conversion for the 1979 Oldsmobile Starfire
A78-13 and B78-13 each have radial-equivalent options that widen the selection path beyond their original bias-ply sizing. For A78-13, the available choices 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 equivalents are 175R13, P175/75R13, P185/70R13, and 650R13 as a bias-look radial. These options use different sizing conventions and profiles, with recommended rim-width ranges of 4-5 inches for A78-13 and 4-6 inches for B78-13, so wheel width and vehicle clearance should be checked before changing formats.
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 questions that come up with a 1979 Oldsmobile Starfire, including sub-model size differences, 13-inch rim fitment, bias-ply versus radial choices, radial equivalents, restoration-minded appearance, and the checks worth making before regular road use.
Tire Size & Fitment
What tire size fits a 1979 Oldsmobile Starfire?
The 1979 Oldsmobile Starfire does not use one universal tire size across the entire model range. Primary fitments include A78-13, B78-13, BR78-13, and BR70-13, all on 13-inch rims. The L-4 uses A78-13 or B78-13 bias-ply sizes, the V6 uses B78-13 bias-ply or BR78-13 radial, and the V8 uses BR70-13 radial.
That means the first step is identifying the exact Starfire sub-model and then confirming what is actually on the car today. A changed wheel set, an earlier tire conversion, or suspension work can alter what fits safely, so the size on the sidewall and the wheel dimensions should both be checked before selecting a replacement.
What size rim does a 1979 Oldsmobile Starfire use?
Every primary tire size used on the 1979 Oldsmobile Starfire here is built around a 13-inch rim diameter. That includes the bias-ply A78-13 and B78-13 sizes as well as the radial BR78-13 and BR70-13 sizes. Rim diameter stays consistent even though the tire sizes and constructions vary by sub-model.
Rim diameter is only part of the fitment picture, so it should not be treated as the only measurement that matters. Wheel width still affects whether a bias-ply size or a radial equivalent is a sensible match, and any owner looking at a construction change should verify the actual wheel dimensions before moving from one size family to another.
Do all 1979 Oldsmobile Starfire sub-models use the same tire size?
No, the 1979 Oldsmobile Starfire sub-models do not all share the same tire size. The L-4 uses A78-13 or B78-13 bias-ply, the V6 uses B78-13 bias-ply or BR78-13 radial, and the V8 uses BR70-13 radial. The fitment split includes both size differences and construction differences across the lineup.
That variation matters because choosing by model name alone can lead to the wrong tire family. An owner should confirm the exact sub-model, look at the tire size already mounted, and check whether the car still has its original wheel setup. That approach helps narrow the selection before comparing sidewall appearance, construction, or radial-equivalent options.
Bias-Ply & Radial Options
Is A78-13 a bias-ply or radial tire for the 1979 Oldsmobile Starfire?
A78-13 is a bias-ply tire size on the 1979 Oldsmobile Starfire. It appears on L-4 applications and uses the vintage alphanumeric bias-ply system rather than a radial format. That makes it part of the Starfire's traditional fitment path rather than one of the model's primary radial sizes such as BR78-13 or BR70-13.
Keeping A78-13 means preserving a period-style bias-ply presentation and staying within the original sizing convention for that application. If a radial alternative is being considered instead, the practical next step is checking the available equivalent sizes against the wheel width, overall vehicle setup, and the amount of clearance available around the tire.
What radial tire sizes are equivalent to B78-13?
Radial equivalents for B78-13 include 175R13 as an 80-series metric radial, P175/75R13 as a 75-series P-metric radial, and P185/70R13 as a 70-series P-metric radial. B78-13 also has a 650R13 bias-look radial equivalent. These choices give the 1979 Oldsmobile Starfire a wider range of radial formats while still referencing the original bias-ply size.
Each of those alternatives follows a different sizing convention, so the choice is not simply about picking any radial with a similar number in the name. The recommended rim-width range for this equivalent group is 4-6 inches, and the owner should still confirm wheel width, tire clearance, and the car's present configuration before making the switch.
What should I check before converting my 1979 Oldsmobile Starfire from bias-ply to radial tires?
A bias-ply to radial conversion on a 1979 Oldsmobile Starfire starts with confirming the original size and sub-model. A78-13 and B78-13 have specific radial-equivalent paths, but the car should still be checked for its current wheel width, 13-inch rim diameter, and enough clearance around the fenders, suspension, and steering components before changing tire format.
A construction change can also alter the overall look and feel of the car, which matters on a late-1970s hatchback that may be restored, preserved, or modified differently from one example to another. It helps to inspect the suspension condition, verify the tires on both axles are matched appropriately, and make sure the planned radial size suits the way the Starfire is actually used.
Choosing the Right Tire
What should I consider when choosing a 1979 Oldsmobile Starfire tire?
Start with the exact sub-model, because the 1979 Oldsmobile Starfire uses four primary sizes and both bias-ply and radial construction. The L-4, V6, and V8 do not all follow the same tire path. That makes size confirmation more important than any appearance or brand preference at the beginning of the selection process.
Once the correct size family is confirmed, the next decision is how the car is being used and presented. A period-style restoration may point toward staying with bias-ply sizing where applicable, while a driver-focused setup may lead to a radial equivalent. Wheel width, tire construction, and the car's current stance should all be checked before finalizing a choice.
How do I choose between the available B78-13 tires for a 1979 Oldsmobile Starfire?
Choosing among B78-13 options for a 1979 Oldsmobile Starfire starts with deciding whether the car should stay with the original bias-ply size or move into one of the radial-equivalent formats tied to B78-13. That size appears on certain L-4 and V6 applications, so the first priority is matching the tire family to the exact Starfire configuration.
From there, compare the goals for the car rather than looking for a one-size-fits-all answer. A traditional presentation may favor the bias-ply route, while a different road-use plan may make one of the radial equivalents worth evaluating. The wheel width range, the car's visual stance, and any previous changes to wheels or suspension should guide the final choice.
What tire series are available for the 1979 Oldsmobile Starfire?
The 1979 Oldsmobile Starfire page centers on fitment first, with primary sizes that span both vintage bias-ply and alphanumeric radial construction. That means the most important distinction is not a broad series comparison across the whole model line, but whether the tire belongs to the correct size and construction path for the specific L-4, V6, or V8 application.
For a buyer, the practical takeaway is to narrow the search by exact size before comparing any tire-series details that may appear in a product grid elsewhere on the page. Once the correct fitment is confirmed, series differences can be weighed against appearance goals, road-use expectations, and whether the Starfire is being kept close to a period-style setup.
Restoration & Appearance
Which tire should I choose for a period-style 1979 Oldsmobile Starfire?
A period-style 1979 Oldsmobile Starfire usually starts with the primary tire size assigned to its exact sub-model, not with a universal tire choice across the whole model line. That could mean A78-13 or B78-13 bias-ply on certain L-4 and V6 applications, or one of the radial primary sizes on later-configuration versions such as the V8's BR70-13.
The most convincing restoration-oriented result comes from matching the car's actual configuration first and then deciding how strictly the appearance should follow a late-1970s presentation. When exact originality matters, period photos, marque-club guidance, and vehicle-specific documentation can help narrow the sidewall and construction choice beyond basic size fitment.
How does tire construction affect the appearance of a restored 1979 Oldsmobile Starfire?
Tire construction changes the visual character of a restored 1979 Oldsmobile Starfire because bias-ply and radial tires present differently even when they reference related sizes. On this model year, both constructions appear in the fitment mix, so the car can take on a more traditional period-style look with bias-ply sizing or a later, more radial-oriented stance where that fitment applies.
That visual difference matters most when the goal is to keep the Starfire aligned with its era rather than simply replacing worn tires. A buyer weighing appearance should look at the exact sub-model, the original size family, and whether a radial equivalent changes the intended presentation. Those details often matter as much as the brand name on a restoration-minded car.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1979 Oldsmobile Starfire?
Yes, modifications can affect tire fitment on a 1979 Oldsmobile Starfire even when the intended tire size is one of the correct original fitments. Aftermarket wheels, altered wheel width, suspension changes, lowering, or body work can all change how much space is available around a 13-inch tire. That matters on a model with several different size paths already in play.
A Starfire that has been changed from stock should be measured rather than judged by model year alone. Tire-to-fender, tire-to-suspension, and steering clearance should be checked before mounting replacements, especially when moving from bias-ply sizing to a radial equivalent. Looking at both front and rear fitment helps avoid assuming the car still matches its original setup.
What should I inspect before driving a 1979 Oldsmobile Starfire on new tires?
Before driving a 1979 Oldsmobile Starfire on new tires, inspect the wheels for the correct 13-inch diameter and confirm the wheel width suits the chosen tire size or radial equivalent. It also makes sense to check lug hardware, valve stems, and visible suspension condition, especially on a car that may have sat for long periods or changed hands several times.
A road-ready check should also include tire pressure, sidewall condition, tread condition, and any sign of rubbing once the car is on the ground and steered lock to lock. Collector-era cars deserve a cautious first drive, so watching for vibration, pull, or unexpected clearance issues early can prevent a fresh tire installation from becoming a fitment problem.
How should tires on a collector 1979 Oldsmobile Starfire be maintained?
Tires on a collector 1979 Oldsmobile Starfire should be inspected regularly even if the car is driven only occasionally. Low-use cars can develop age-related issues such as cracking, flat spotting, air loss, or sidewall deterioration long before the tread looks worn. That applies to both the Starfire's bias-ply fitments and its radial tire options.
Storage conditions matter almost as much as mileage on a car from this era. Keeping the Starfire away from prolonged sunlight, excess heat, moisture, and ozone sources helps protect tire condition, and maintaining correct inflation reduces stress while the car sits. A quick inspection before each drive is a smart habit, especially before highway use or longer trips.
