The 1974 Imperial represents Chrysler luxury in its full-size, formal-era form, with the long, substantial presence that defined premium American motoring in the mid-1970s. Owners restoring or maintaining one today usually want a tire that supports that character as much as it supports the car itself. For this exact fitment, the 1974 Imperial All Models uses LR78-15 on a 15-inch rim, and the primary tire choice centers on radial construction rather than an earlier bias-ply layout. Available options also bring a traditional presentation through a narrow whitewall and a bias-profile radial design. That makes tire selection less about finding the size and more about matching the car's appearance, wheel dimensions, and intended road use.
Which Tire Size Is Right for The 1974 Imperial All Models
The 1974 Imperial All Models uses one primary tire size: LR78-15. It is a radial fitment on a 15-inch rim, and the same size carries across the covered Base sub-model, so the real decision is choosing the right tire style within that size and confirming wheel width, appearance goals, and overall vehicle setup before installation.
LR78-15 is a vintage alphanumeric radial size. In this format, the lettered size class works with the series designation, the R identifies radial construction, and the 15 refers to the wheel diameter in inches. On a 1974 Imperial, that matters because the car's fitment is already centered on radial construction rather than a bias-ply substitute. Available LR78-15 choices include a Firestone tire in the Wide Oval Radial series with a narrow whitewall and a bias-profile radial appearance. It is the right size to evaluate when preserving the car's large luxury-car stance while still checking wheel width and clearance on the actual vehicle.
Fitment is straightforward for the covered 1974 Imperial sub-models. The Base model uses the same LR78-15 radial size, so the key job is confirming the actual wheel setup on the car and then choosing the tire style that best suits its appearance and use.
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1974 Imperial All Models Base
The 1974 Imperial All Models Base uses the same LR78-15 radial fitment as the rest of this covered application. That keeps tire selection focused on wheel compatibility, whitewall presentation, and whether a bias-profile radial look suits the car's restoration direction and road use.
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 1974 Imperial All Models Tires for Sale
Available LR78-15 choices focus on traditional full-size luxury-car presentation rather than broad size variation. The current offering centers on Firestone's Wide Oval Radial series with a narrow whitewall, bias-profile radial styling, and a rim-width range that supports careful wheel matching.
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Bias Profile Radial
Firestone Steel Belted 721 |.75 Inch Whitewall | LR78-15
These FAQs focus on the exact LR78-15 fitment for the 1974 Imperial, including rim size, radial construction, sidewall presentation, product selection, and the checks that matter before putting a large collector-era luxury car back on the road.
Tire Size & Fitment
What tire size fits a 1974 Imperial All Models?
The 1974 Imperial All Models uses LR78-15 tires. That is the primary fitment for this application, and it is a radial tire size mounted on a 15-inch wheel.
Because this Imperial fitment centers on one size, the main task is not sorting through multiple primary sizes but confirming that the car still has the correct wheel setup. A car that has seen aftermarket wheel changes, suspension work, or long-term storage should be checked for wheel width, tire clearance, and overall condition before a new LR78-15 is selected.
What size rim does a 1974 Imperial All Models use?
The 1974 Imperial All Models uses a 15-inch rim with its LR78-15 tire size. That rim diameter is built into the tire designation, and the available LR78-15 product for this application is also built for a 15-inch wheel.
Rim diameter is only one part of the fitment picture, especially on a large luxury car that may have changed hands several times. The wheel should also be checked for proper width, condition, and any aftermarket changes. Staying with the correct 15-inch diameter keeps the fitment process grounded before moving on to appearance choices such as whitewall treatment.
Does the 1974 Imperial All Models Base use the same tire size?
Yes. The 1974 Imperial All Models Base uses the same LR78-15 radial tire size as this covered fitment. That makes sub-model selection relatively simple compared with vehicles that split tire sizes by trim or package.
Even with shared fitment, the actual car still deserves a quick wheel and clearance check before replacement tires are chosen. Collector cars are often modified over time, and wheels do not always remain original to the car. Once the wheel setup is confirmed, the decision usually comes down to sidewall appearance, radial style, and the kind of driving the Imperial will see.
Choosing the Right Tire
What should I consider when choosing a LR78-15 tire for a 1974 Imperial All Models?
Start with the correct LR78-15 size and the 15-inch wheel requirement, then look at the tire's overall character. For this Imperial application, the available tire combines radial construction with a bias-profile look, which can matter to owners who want a traditional visual presentation without leaving the radial format.
Selection should also take the wheel itself into account, not just the tire code on the sidewall. Compare rim width, load capacity, and the car's actual stance and clearance before committing to a tire. On a full-size 1974 Imperial, the right choice often balances authentic-looking proportions, whitewall style, and the condition of the car's suspension and steering components.
What sidewall styles are available for 1974 Imperial All Models tires?
The available LR78-15 tire for the 1974 Imperial uses a narrow whitewall. That sidewall treatment suits the formal, upscale look many owners want on a mid-1970s Imperial without shifting the car into a more stripped or performance-oriented appearance.
Sidewall choice affects how the whole car reads from a distance, especially on a large luxury model with a tall body side and substantial wheel openings. A narrow whitewall can complement a restoration-oriented presentation, but it is still worth comparing that look against the car's trim, wheel covers, and overall finish so the tire does not visually fight the rest of the build.
What brands offer tires for the 1974 Imperial All Models?
Firestone is the brand currently represented in the available LR78-15 fitment for the 1974 Imperial All Models. The applicable offering is part of the Wide Oval Radial series and uses a narrow whitewall with a bias-profile radial appearance.
Brand alone should not be the only deciding factor on a collector-era luxury car. It helps to compare the tire's construction style, sidewall presentation, rim-width compatibility, and load specification alongside the brand name. That approach keeps the choice centered on how the tire suits the Imperial's wheel setup and intended use, rather than reducing the decision to a logo.
Restoration & Appearance
Which tire should I choose for a period-style 1974 Imperial All Models?
A period-style 1974 Imperial usually starts with the correct LR78-15 sizing and a tire that supports the car's formal luxury look. In this fitment, a radial tire with a bias-profile appearance and narrow whitewall offers a traditional presentation that aligns well with the Imperial's era.
Appearance decisions should still be made in the context of the whole car. Wheel covers, ride height, trim level details, and restoration goals can all influence whether a given sidewall treatment looks right. When exact originality matters, marque-specific references and historical vehicle documentation are useful checkpoints before settling on any one visual style.
How does tire construction affect the appearance of a restored 1974 Imperial All Models?
Tire construction influences more than ride and handling; it also changes the visual character of the car. On a restored 1974 Imperial, an LR78-15 radial with a bias-profile look can preserve a more traditional sidewall shape than a more modern-looking radial design with less period presence.
That visual effect matters on a big Imperial because the car carries so much of its identity through proportion and stance. The tire should complement the wheel opening, wheel cover style, and whitewall treatment rather than distract from them. Construction choice becomes part of the restoration's overall look, not just a hidden technical detail.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1974 Imperial All Models?
Yes. Even though the 1974 Imperial All Models uses LR78-15 on a 15-inch rim, modifications can change how that size works on the actual car. Aftermarket wheels, altered ride height, suspension changes, or brake upgrades can all affect clearance and wheel compatibility.
A fitment check should include wheel width, steering clearance, and the relationship between the tire and the fender opening at full turn and normal ride height. Full-size cars are often changed over time, especially in the collector market. Confirming the car's current setup helps prevent choosing a tire only by size code without checking how the vehicle now sits.
What should I inspect before driving a 1974 Imperial All Models on new tires?
Before road use, inspect the wheels, valve stems, lug hardware, and the general condition of the suspension and steering components. Tire pressure should be set appropriately for the installed tire, and the tires themselves should be checked for proper seating, visible damage, and any early signs of air loss after installation.
A 1974 Imperial is a substantial car, so road manners depend on more than fresh rubber alone. It helps to verify alignment, look for worn bushings or loose front-end parts, and confirm that the tires clear the body and chassis through normal movement. A short local test drive and recheck can catch issues before a longer outing.
How should LR78-15 tires on a collector 1974 Imperial All Models be maintained?
LR78-15 tires on a collector Imperial should be kept properly inflated, inspected regularly, and protected from long periods of heat, sunlight, moisture, and ozone exposure. Sidewalls and tread should be checked for cracking, cuts, bulges, and uneven wear, especially on a car that spends more time parked than driven.
Low annual mileage does not eliminate tire aging, and large luxury cars can mask problems until they become serious. Regular pressure checks, occasional movement of the vehicle, and a visual inspection before each outing are worthwhile habits. On a seldom-driven Imperial, tire condition matters just as much as tread depth when deciding whether the car is ready for the road.
