The 1973 American Motors Ambassador came at the close of AMC’s full-size era, giving buyers a roomy, distinctly early-1970s American car with traditional proportions and comfort-oriented character. That matters when choosing tires, because this exact model spans several period fitments rather than one universal size. The 1973 American Motors Ambassador uses F78-14, G78-14, H78-14, and HR78-14 tires on 14-inch rims, with both bias-ply and radial fitments depending on sub-model. Available choices also vary by whitewall treatment, brand, and tire series, while several bias-ply sizes have modern radial equivalents. The key is matching the correct size to the exact sub-model, then deciding how closely the tire should follow a restoration-oriented look or a road-use-focused alternative.
Which Tire Size Is Right for The 1973 American Motors Ambassador
Four primary tire sizes apply to the 1973 American Motors Ambassador, and the correct one depends on the exact sub-model. All of them use a 14-inch rim, but fitment varies by both size and construction, since the Base uses bias-ply sizes while the Wagon appears with both a bias-ply and a radial fitment. The first step is identifying the sub-model, then matching the tire to the wheel and intended use.
F78-14 is a vintage alphanumeric bias-ply size in which the letter and number work together to identify the tire’s width and profile family, while the 14 designates a 14-inch wheel. On the 1973 American Motors Ambassador, it represents a traditional bias-ply fitment with the upright look and period-style construction many restoration-minded owners want. Available choices in this size include a Coker Classic Bias Ply with a wide whitewall presentation. It is the size to evaluate when keeping a Base-model Ambassador close to a traditional full-size American-car appearance and feel.
G78-14 follows the same vintage alphanumeric bias-ply sizing system, with the final 14 again indicating a 14-inch rim. For the 1973 American Motors Ambassador, this is another primary bias-ply fitment used on the Base, but it opens up more visible choice than F78-14. G78-14 is available from BFGoodrich and Coker Classic, with sidewall treatments that include dual white stripe, narrow whitewall, and wide whitewall styles across Silvertown Classic Bias Ply and Coker Classic Bias Ply series. It is the size to review when appearance details matter as much as correct basic fitment.
H78-14 is also a vintage alphanumeric bias-ply tire size, with the same 14-inch wheel diameter but a larger size class than the F- and G-series fitments. On the 1973 American Motors Ambassador, it is one of the Wagon tire sizes and keeps the vehicle in a traditional bias-ply configuration. The available H78-14 product carries a Coker Classic Bias Ply series and a wide whitewall sidewall style, which suits owners looking for a substantial, restoration-oriented presentation. This size deserves close attention when the goal is preserving the Wagon’s period tire profile rather than shifting immediately to a radial alternative.
HR78-14 uses an alphanumeric radial format, where the R indicates radial construction within a period-style sizing system and the 14 still denotes a 14-inch rim. On the 1973 American Motors Ambassador, this size is associated with the Wagon and stands apart from the bias-ply fitments used elsewhere in the range. Its practical importance is construction choice as much as size, since a buyer may be comparing a period-style radial setup against a traditional H78-14 bias-ply presentation. It is the fitment to confirm carefully when the vehicle already carries radial-type wheels and a Wagon-specific configuration.
Sub-model fitment matters on the 1973 American Motors Ambassador because the covered configurations do not all use the same tire size. The Base stays within bias-ply F78-14 and G78-14 fitments, while the Wagon spans both H78-14 bias-ply and HR78-14 radial sizing on 14-inch rims.
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1973 American Motors Ambassador Base
The 1973 American Motors Ambassador Base uses F78-14 and G78-14 bias-ply tire sizes on 14-inch rims. That makes the selection process less about construction changes and more about choosing the correct size first, then narrowing the tire by sidewall appearance and series character.
The 1973 American Motors Ambassador Wagon uses H78-14 bias-ply and HR78-14 radial fitments on 14-inch rims. This makes wheel confirmation especially important, since the buying decision may involve both the correct size and whether the Wagon remains in a traditional bias-ply setup or a period-style radial one.
Bias-Ply to Radial Tire Conversion for the 1973 American Motors Ambassador
F78-14 has four radial-equivalent paths: 195R14 as an 80-series metric radial, P205/75R14 as a 75-series P-metric radial, P215/70R14 as a 70-series P-metric radial, and 750R14 as a bias-look radial equivalent. G78-14 corresponds to 205R14, P215/75R14, P225/70R14, and 800R14 in the same sequence. H78-14 maps to 215R14, P225/75R14, and P235/70R14. Recommended rim widths are 4-6 inches for F78-14 and 5-7 inches for G78-14 and H78-14, so wheel width, overall dimensions, and clearance should all be checked before changing sizes or construction.
Modern Radial Equivalents
195R14
Equivalent 80-series Metric Radial (F78-14)
P205/75R14
Equivalent P-metric 75-series Radial (F78-14)
P215/70R14
Equivalent P-metric 70-series Radial (F78-14)
750R14
Bias-look Radial Equivalent (F78-14)
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 American Motors Ambassador Tires for Sale
Available 14-inch Ambassador tires center on bias-ply F78-14, G78-14, and H78-14 sizes from Coker Classic and BFGoodrich. Buyers can compare Coker Classic Bias Ply and Silvertown Classic Bias Ply series, with sidewall choices that include wide whitewall, narrow whitewall, and dual white stripe treatments.
Common 1973 American Motors Ambassador tire questions usually come down to exact sub-model fitment, 14-inch rim compatibility, bias-ply versus radial choices, and how sidewall style affects the finished look. The answers below focus on selecting the correct size first, then narrowing the right tire for restoration or road use.
Tire Size & Fitment
What tire size fits a 1973 American Motors Ambassador?
The 1973 American Motors Ambassador uses four primary tire sizes: F78-14, G78-14, H78-14, and HR78-14. F78-14 and G78-14 are bias-ply sizes used on the Base, while the Wagon uses H78-14 in bias-ply form and HR78-14 in radial form, all on 14-inch rims.
That means tire selection starts with the exact sub-model rather than the model name alone. A Base and a Wagon do not share the same fitment range, and the Wagon also introduces a construction difference. Before choosing a tire, confirm the sub-model, check the actual wheel diameter on the car, and make sure the current wheel setup has not been changed over the years.
What size rim does a 1973 American Motors Ambassador use?
The tire fitments covered for the 1973 American Motors Ambassador all use a 14-inch rim diameter. That applies across F78-14, G78-14, H78-14, and HR78-14, so the key wheel measurement is consistent even though the tire sizes and constructions vary by sub-model.
Rim diameter consistency does not eliminate the need to verify the rest of the wheel setup. Wheel width still matters, especially if the car has replacement wheels, and a radial conversion should be checked more carefully than a same-size bias-ply replacement. Looking at the stamping on the wheel or measuring the existing wheel can prevent ordering a correct tire size for the wrong wheel configuration.
Do all 1973 American Motors Ambassador sub-models use the same tire size?
No. The 1973 American Motors Ambassador Base uses F78-14 and G78-14 bias-ply sizes, while the Wagon uses H78-14 bias-ply and HR78-14 radial fitments. The model range shares a 14-inch rim diameter, but it does not share one universal tire size or one universal construction type.
That difference is important because a buyer can easily end up comparing the wrong tires if the sub-model is not confirmed first. The Wagon adds both a larger bias-ply size and a radial-format size, which changes the decision from simple replacement to setup verification. Matching the sub-model first keeps the next comparison focused on the right size, style, and construction.
Bias-Ply & Radial Options
Is HR78-14 a bias-ply or radial tire for the 1973 American Motors Ambassador?
HR78-14 is a radial tire size for the 1973 American Motors Ambassador. It uses an alphanumeric radial format, with the R in the size indicating radial construction, and it appears with the Wagon rather than the Base bias-ply fitments.
That distinction matters because HR78-14 should not be treated as just another version of an H78-14 bias-ply tire. Construction affects how the tire is chosen, how the wheel setup is evaluated, and whether the car is being kept in a traditional bias-ply presentation or a period-style radial one. Wheel width, overall dimensions, and vehicle clearance should be confirmed before changing from one construction style to the other.
What radial tire sizes are equivalent to F78-14, G78-14, and H78-14?
F78-14 corresponds to 195R14, P205/75R14, P215/70R14, and 750R14 as a bias-look radial. G78-14 corresponds to 205R14, P215/75R14, P225/70R14, and 800R14 as a bias-look radial. H78-14 corresponds to 215R14, P225/75R14, and P235/70R14.
Those equivalent sizes give Ambassador owners several ways to compare modern radial formats with original-style bias-ply fitments. The 80-series metric sizes keep a traditional metric-radial convention, the 75-series and 70-series P-metric options offer alternate radial sizing paths, and the bias-look radial choices preserve a more vintage visual theme. Each one still needs to be checked against wheel width, tire dimensions, and clearance before any conversion is finalized.
What should I check before converting my 1973 American Motors Ambassador from bias-ply to radial tires?
Start by confirming the Ambassador’s exact sub-model, current wheel diameter, and the original bias-ply size you are replacing. Then compare only the radial equivalent sizes associated with that primary fitment, such as 195R14, P205/75R14, or P215/70R14 for F78-14, and verify the wheel’s width against any stated rim-width guidance.
A conversion should also account for the car’s actual condition and setup. Steering clearance, fender space, suspension height, and wheel choice all matter, especially on a vehicle that may have seen decades of changes. For a Wagon, the presence of HR78-14 adds another reason to confirm what is already on the car rather than assuming every Ambassador used the same construction.
Choosing the Right Tire
What should I consider when choosing a 1973 American Motors Ambassador tire?
The first priority is choosing the correct primary size for the exact sub-model: F78-14 or G78-14 for the Base, and H78-14 or HR78-14 for the Wagon. After that, the main considerations are construction type, wheel compatibility, and whether the goal is a traditional bias-ply appearance or a radial-oriented setup.
Once the fitment is narrowed, details such as sidewall treatment, tire series, and brand become more useful comparison points. A buyer focused on restoration presentation may lean toward a specific whitewall style, while another owner may be comparing a bias-ply replacement with a radial equivalent path. The right choice comes from balancing vehicle configuration, appearance goals, and the way the car will actually be used.
What sidewall styles are available for 1973 American Motors Ambassador tires?
Available sidewall styles for 1973 American Motors Ambassador tires include wide whitewall, narrow whitewall, and dual-white-stripe treatments. Those choices appear across the bias-ply F78-14, G78-14, and H78-14 fitments, with the broadest visible variety showing up in G78-14 offerings.
Sidewall style has a strong effect on the finished look of a full-size 1973 Ambassador, especially if the car is being restored or kept in a period-style presentation. It is best to choose the correct tire size and construction first, then compare whitewall width and stripe treatment within that fitment. That keeps appearance decisions from leading to a tire that looks right but does not match the intended setup.
What brands offer tires for the 1973 American Motors Ambassador?
Coker Classic and BFGoodrich both appear among the available tire options for the 1973 American Motors Ambassador. Coker Classic covers F78-14, G78-14, and H78-14 in the Coker Classic Bias Ply series, while BFGoodrich appears in G78-14 through the Silvertown Classic Bias Ply series.
Brand is only one part of the decision, because the available Ambassador tires also vary by size, sidewall style, and series character. A buyer comparing G78-14 options, for example, may be looking at narrow whitewall, wide whitewall, or dual-white-stripe presentations rather than a simple brand choice. It helps to compare the complete combination of size, construction, appearance, and wheel compatibility instead of isolating one brand name.
Restoration & Appearance
Which tire should I choose for a period-style 1973 American Motors Ambassador?
A period-style 1973 American Motors Ambassador should start with the correct original-format fitment for its sub-model: F78-14 or G78-14 for the Base, and H78-14 or HR78-14 for the Wagon. For many restoration-oriented owners, that means beginning with the proper alphanumeric size and deciding whether to stay with bias-ply construction or evaluate a radial alternative separately.
Appearance then comes down to the tire’s visual details rather than size alone. Wide whitewall, narrow whitewall, and dual-white-stripe treatments can give the car very different character even when the fitment is otherwise correct. When exact originality is especially important, period photos, marque references, and vehicle-specific historical documentation are worth reviewing before choosing a final sidewall presentation.
How does tire construction affect the appearance of a restored 1973 American Motors Ambassador?
Tire construction influences the visual character of a restored 1973 American Motors Ambassador as much as it affects the technical setup. A bias-ply tire keeps the traditional alphanumeric format and vintage presentation associated with full-size American cars of the period, while a radial equivalent can change the look even if it stays close in overall fitment intent.
That difference is especially relevant when the car is being judged by its overall period impression rather than simply prepared for casual driving. A bias-look radial can help bridge those priorities on some sizes, but it still needs to be treated as an alternative rather than the same thing as a bias-ply tire. Matching the sub-model first keeps the appearance decision grounded in the correct fitment.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1973 American Motors Ambassador?
Yes. A 1973 American Motors Ambassador may no longer have its original wheels, ride height, or suspension settings, and any of those changes can affect tire fitment even when the intended size is correct for the sub-model. Wheel width, wheel offset, and body clearance become especially important if the car has been altered over time.
That is why the actual car should be inspected before choosing between sizes or converting from bias-ply to radial. A Wagon using HR78-14 or an owner considering one of the radial equivalents for F78-14, G78-14, or H78-14 should confirm clearance at full steering angle and through suspension travel. Modified cars require setup verification, not just a catalog-size match.
What should I inspect before driving a 1973 American Motors Ambassador on new tires?
Before driving a 1973 American Motors Ambassador on new tires, inspect the wheels, valve stems, lug hardware, and the general condition of the suspension and steering components. Tire pressure should be set correctly for the tire being used, and the car should be checked for any rubbing or interference once the new tires are mounted.
A short, careful test drive is a smart final step, especially on a collector car that may have been parked for long periods. Pay attention to vibration, pull, or contact sounds that suggest a wheel or clearance issue. It also helps to recheck air pressure and fastener tightness after the first miles, since an old vehicle often reveals small setup problems only after returning to road use.
How should F78-14, G78-14, H78-14, or HR78-14 tires on a collector 1973 American Motors Ambassador be maintained?
Collector-car tires on a 1973 American Motors Ambassador should be maintained with regular pressure checks, visual inspection, and careful storage habits. Whether the car uses F78-14, G78-14, H78-14, or HR78-14, owners should watch for cracking, bulges, cuts, uneven wear, and slow air loss, especially if the car is driven only occasionally.
Storage conditions matter as much as mileage on an older collector vehicle. Keeping the Ambassador away from prolonged sun, excess heat, moisture, and ozone sources helps protect sidewalls and tread over time. It is also wise to inspect the tires before every longer outing rather than assuming low miles mean low risk, since age and inactivity can affect collector tires significantly.
