The 1973 Buick Century arrived at a moment when Detroit intermediates were balancing personal-luxury styling, family-car duty, and, in Gran Sport form, a more performance-minded image. That mix matters when choosing tires, because this exact Century can use several 14-inch fitments depending on sub-model, including G70-14, G78-14, GR70-14, and H78-14. Most primary fitments are bias-ply, while the Gran Sport also brings a period radial size into the picture. Available choices range from redline, raised white letter, and stripe treatments to wide whitewall options, so the right selection depends on whether the goal is muscle-era character, restoration-oriented appearance, or sensible road-use planning.
Which Tire Size Is Right for The 1973 Buick Century
The 1973 Buick Century uses four primary tire sizes, and the right one depends on the exact sub-model. All of them fit 14-inch wheels, but Century fitment spans both bias-ply and radial construction, so identifying whether the car is a Base, Gran Sport, or Wagon is the first step before comparing appearance, tire series, or radial-equivalent choices.
G70-14 is a vintage alphanumeric bias-ply size in which the letter identifies the tire's size class, the 70 marks its profile family, and the 14 designates a 14-inch rim. On the 1973 Buick Century, it serves buyers looking for a traditional bias-ply fitment, especially where a muscle-era presentation matters. Available choices include Firestone Wide Oval and Goodyear Custom Wide Tread tires with redline, raised white letter, pin white stripe, and blackwall sidewall treatments. It is the size to evaluate when the car calls for G70-14 specifically and appearance is a major part of the decision.
G78-14 is also a vintage alphanumeric bias-ply size, with the letter and two-digit series working together to indicate its period sizing family and the 14 confirming wheel diameter. For a 1973 Buick Century, this size points more toward a traditional bias-ply replacement with an emphasis on whitewall styling. Available products include BFGoodrich Silvertown Classic Bias Ply and Coker Classic Bias Ply options with narrow whitewall, dual white stripe, and wider whitewall treatments. It is the size to focus on when the car is set up for G78-14 and a more formal or restoration-oriented sidewall look is important.
GR70-14 is an alphanumeric radial size, with the R built into the designation to show radial construction while the final 14 still refers to a 14-inch rim. On the 1973 Buick Century, this size matters because it gives the Gran Sport a primary radial fitment rather than a bias-ply-only starting point. That makes construction choice part of the vehicle's original fitment story, not just a later conversion question. It is the size to confirm when selecting tires for a Gran Sport that was set up around a period radial format and 14-inch wheel compatibility.
H78-14 is a vintage alphanumeric bias-ply size that steps into a larger size class, with the 14 again indicating a 14-inch rim. On the 1973 Buick Century, this size is tied to the Wagon and supports a bias-ply fitment distinct from the Base and Gran Sport combinations. The available product uses a Coker Classic Bias Ply series with a wide whitewall presentation, giving it a traditional station-wagon look. It is the right size to review when confirming Wagon fitment and checking that the wheel and overall setup still match the original 14-inch configuration.
Sub-model fitment matters on the 1973 Buick Century because tire size is not the same across the full range. Base, Gran Sport, and Wagon models use different 14-inch fitment paths, so confirming the exact sub-model is the clearest way to avoid choosing the wrong size or construction.
1
1973 Buick Century Base
The 1973 Buick Century Base uses bias-ply fitments and can be equipped with either G70-14 or G78-14. That means the decision is less about wheel diameter and more about confirming which of the two primary sizes belongs on the car before choosing among sidewall treatments and tire series.
The 1973 Buick Century Gran Sport can use either G70-14 bias-ply or GR70-14 radial fitment. That makes this sub-model especially important to verify, because the choice may involve preserving a bias-ply presentation or staying with a period radial size on the same 14-inch wheel diameter.
The 1973 Buick Century Wagon uses the H78-14 bias-ply size. Tire selection is therefore straightforward once Wagon fitment is confirmed, with attention shifting to maintaining the correct 14-inch wheel setup and choosing a sidewall style that suits the vehicle’s traditional appearance.
Bias-Ply to Radial Tire Conversion for the 1973 Buick Century
G70-14 and G78-14 each have four radial-equivalent paths, while H78-14 has three. For G70-14 and G78-14, the alternatives are 205R14 as an 80-series metric radial, P215/75R14 as a 75-series P-metric radial, P225/70R14 as a 70-series P-metric radial, and 800R14 as a bias-look radial. H78-14 can be compared with 215R14, P225/75R14, and P235/70R14. These choices span traditional metric, P-metric, and bias-look formats; the recommended rim-width range is 5 to 7 inches, and wheel match plus vehicle clearance should be checked before changing sizes or construction.
Modern Radial Equivalents
205R14
Equivalent 80-series Metric Radial (G70-14)
P215/75R14
Equivalent P-metric 75-series Radial (G70-14)
P225/70R14
Equivalent P-metric 70-series Radial (G70-14)
800R14
Bias-look Radial Equivalent (G70-14)
205R14
Equivalent 80-series Metric Radial (G78-14)
P215/75R14
Equivalent P-metric 75-series Radial (G78-14)
P225/70R14
Equivalent P-metric 70-series Radial (G78-14)
800R14
Bias-look Radial Equivalent (G78-14)
215R14
Equivalent 80-series Metric Radial (H78-14)
P225/75R14
Equivalent P-metric 75-series Radial (H78-14)
P235/70R14
Equivalent P-metric 70-series Radial (H78-14)
Important Considerations When Replacing Bias Ply With Radial
Compare overall diameter and section width carefully to ensure proper fit.
Verify recommended rim range (5-7 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.
Best 1973 Buick Century Tires for Sale
Available 1973 Buick Century tires cover Firestone, Goodyear, BFGoodrich, and Coker Classic offerings across Wide Oval, Custom Wide Tread, Silvertown Classic Bias Ply, and Coker Classic Bias Ply series. Sidewall choices include redline, raised white letter, blackwall, pin white stripe, narrow whitewall, dual white stripe, and wide whitewall treatments.
1973 Buick Century tire questions usually come down to sub-model fitment, 14-inch wheel compatibility, bias-ply versus radial selection, and sidewall appearance. The details below focus on how those choices affect Base, Gran Sport, and Wagon owners.
Tire Size & Fitment
What tire size fits a 1973 Buick Century?
A 1973 Buick Century can use G70-14, G78-14, GR70-14, or H78-14, depending on the exact sub-model. Base models use G70-14 or G78-14, the Gran Sport uses G70-14 or GR70-14, and the Wagon uses H78-14. All of these are 14-inch fitments, but they are not interchangeable simply because the wheel diameter matches.
The practical first step is confirming whether the car is a Base, Gran Sport, or Wagon and then matching the tire to that setup. Once the sub-model is settled, the real decision becomes construction type, sidewall appearance, and whether a radial equivalent is being considered for a bias-ply size.
What size rim does a 1973 Buick Century use?
The 1973 Buick Century uses 14-inch rims across its primary tire fitments. G70-14, G78-14, GR70-14, and H78-14 all share the same 14-inch rim diameter, which keeps wheel diameter straightforward even though the car can use more than one tire size and more than one construction type.
That shared diameter does not remove the need to confirm the exact wheel and tire combination already on the car. Width, tire construction, and overall tire dimensions still matter, especially if the Century has replacement wheels, a Gran Sport radial setup, or a tire-size change being considered for appearance or road use.
Why does the 1973 Buick Century have more than one tire size?
The 1973 Buick Century has more than one tire size because fitment varies by sub-model and, in one case, by construction type. Base models can use G70-14 or G78-14, the Gran Sport can use G70-14 or GR70-14, and the Wagon uses H78-14. Buick’s Century range covered different roles, so one tire size does not apply to every version.
That means tire selection should start with the exact version of the car rather than a general Century search. A Gran Sport owner may need to sort out bias-ply versus radial fitment, while a Wagon owner is dealing with a different size class entirely, even though all use 14-inch wheels.
Bias-Ply & Radial Options
Is G70-14 a bias-ply or radial tire for the 1973 Buick Century?
G70-14 is a bias-ply tire size on the 1973 Buick Century. It appears as a primary fitment on the Base and Gran Sport, and the available products in that size are bias-ply tires from Firestone and Goodyear in several period-style sidewall treatments and tire series.
That matters because G70-14 should be viewed as a traditional bias-ply fitment first, even though radial alternatives exist in equivalent sizing. Anyone comparing it with a radial option should confirm wheel width, overall fit on the car, and whether the goal is preserving bias-ply character or moving toward a radial-style driving setup.
What radial tire sizes are equivalent to G70-14 on a 1973 Buick Century?
Radial equivalents for G70-14 include 205R14 as an 80-series metric radial, P215/75R14 as a 75-series P-metric radial, P225/70R14 as a 70-series P-metric radial, and 800R14 as a bias-look radial. Each of these provides a different way to compare a modern radial-style option against the original G70-14 bias-ply sizing format.
Those alternatives share the same general replacement conversation, but they are not automatic substitutes. The 5 to 7 inch recommended rim-width range is a useful checkpoint, and clearance, wheel width, and the car’s current setup should all be reviewed before moving from the original bias-ply size to any radial equivalent.
Should I use bias-ply or radial tires on a 1973 Buick Century?
That depends on the exact 1973 Buick Century and the result being pursued. G70-14, G78-14, and H78-14 are bias-ply primary fitments, while GR70-14 is a primary radial fitment for the Gran Sport. A bias-ply choice keeps the car aligned with its original-style sizing format, while a radial equivalent may be considered for certain bias-ply sizes.
Construction choice affects more than just looks. A restoration-oriented Base or Wagon may stay bias-ply for period presentation, while a Gran Sport already tied to GR70-14 has a radial fitment story of its own. Wheel compatibility, suspension condition, and the actual use of the car should all be checked before changing construction.
Choosing the Right Tire
What should I consider when choosing a G70-14 tire for a 1973 Buick Century?
Start by confirming that G70-14 is the correct primary size for the specific 1973 Buick Century, since this model range also uses G78-14, GR70-14, and H78-14. Once size is confirmed, the main choices within G70-14 are bias-ply product series, sidewall style, brand, rim-width compatibility, and the appearance the car should carry on the road or at shows.
Firestone Wide Oval and Goodyear Custom Wide Tread options give G70-14 buyers several period-style directions, including redline, raised white letter, pin white stripe, and blackwall. Rim-width specs vary by product, so wheel width should be checked before narrowing the choice to appearance alone.
What sidewall styles are available for 1973 Buick Century tires?
1973 Buick Century tires are available with a broad range of sidewall styles, depending on size. G70-14 offers redline, raised white letter, pin white stripe, and blackwall choices, while G78-14 adds narrow whitewall, dual white stripe, and wider whitewall treatments. H78-14 is available with a wide whitewall presentation.
That variety means sidewall selection can strongly shape the car’s overall look even when the size stays correct. Gran Sport buyers may lean toward a muscle-era presentation, while Base and Wagon owners may prefer a more formal whitewall appearance, but the sidewall should still be chosen only within the tire size that matches the car.
What brands offer tires for the 1973 Buick Century?
The 1973 Buick Century is covered by products from Firestone, Goodyear, BFGoodrich, and Coker Classic, depending on the tire size being matched to the car. G70-14 centers on Firestone and Goodyear, G78-14 includes BFGoodrich and Coker Classic options, and H78-14 is represented by a Coker Classic bias-ply offering.
Brand matters mainly as part of a broader selection process that also includes tire series, sidewall style, and wheel compatibility. A buyer comparing brands should first stay within the correct Century tire size, then look at whether the tire’s construction and visual character suit the intended restoration style or road-use plan.
Restoration & Appearance
Which tire should I choose for a period-style 1973 Buick Century?
A period-style 1973 Buick Century usually starts with the correct primary size for the exact sub-model and, in many cases, a bias-ply construction. G70-14, G78-14, and H78-14 all support that traditional direction, while the Gran Sport also introduces GR70-14 as a period radial fitment to consider where appropriate.
Once the proper size is established, the appearance decision becomes more specific. Redline, raised white letter, blackwall, stripe, and whitewall treatments can all change the car’s character, so owners aiming for high-level originality should compare the vehicle against marque references or restoration records before settling on a sidewall style.
How does tire construction affect the appearance of a restored 1973 Buick Century?
Tire construction changes the visual impression of a restored 1973 Buick Century even before the car moves. A bias-ply tire usually supports a more traditional 1970s presentation in sizes like G70-14, G78-14, and H78-14, while a radial format such as GR70-14 or a radial equivalent can give the car a different stance and sidewall character.
That is especially relevant on a model line that spans Base, Gran Sport, and Wagon trim paths. A restoration-oriented choice should balance the correct Century fitment with the look the owner wants to preserve, then confirm the selected tire still works with the wheel setup and intended driving use.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1973 Buick Century?
Yes. A 1973 Buick Century may use the correct nominal tire size on paper and still run into fitment issues if the car has aftermarket wheels, altered ride height, suspension changes, or body modifications. Even though the primary fitments all use 14-inch rims, wheel width and the tire’s actual section dimensions still influence clearance.
That is especially important when evaluating radial equivalents for a bias-ply size or sorting out a Gran Sport’s bias-ply versus radial setup. A modified Century should be checked for steering clearance, fender clearance, and wheel match before a tire is chosen simply because it shares the expected rim diameter.
What should I inspect before driving a 1973 Buick Century on new tires?
Before driving a 1973 Buick Century on new tires, inspect the wheels for correct diameter and condition, confirm the tire size matches the exact sub-model, and make sure inflation is set appropriately for the tire being installed. It also helps to look over the suspension and steering so the new tires are not being asked to work with worn components.
A slow walkaround after installation is worthwhile. Check for even clearance at the fenders and inner wheel openings, then watch for rubbing on turns or over bumps during the first drive. On a collector car, that extra care matters because the tire may be new even if the rest of the running gear is not.
How should tires on a collector 1973 Buick Century be maintained?
Tires on a collector 1973 Buick Century should be kept properly inflated, inspected regularly for cracking, cuts, bulges, uneven wear, and slow air loss, and protected from long periods of heat, sunlight, moisture, and ozone exposure. Low annual mileage does not stop a collector tire from aging, so condition matters as much as tread depth.
Storage habits are part of maintenance too. A Century that sits for extended periods benefits from periodic pressure checks and routine visual inspections before every road outing. Owners should also recheck the tires after any wheel, brake, or suspension work, since even small setup changes can affect how a vintage-size tire behaves.
