The 1979 Dodge Magnum XE came at the end of Chrysler’s personal-luxury coupe era, blending long-hood styling with the bold road presence buyers expected in the late 1970s. For owners today, tire selection matters because this exact Magnum XE uses 15-inch vintage alphanumeric radial sizes, with fitment changing by engine configuration. FR78-15, GR78-15, and HR78-15 all appear on this model line, so the first step is matching the tire to the car’s actual setup. Once that is confirmed, the decision shifts toward the right radial size and period-style overall presentation. That makes wheel verification and sub-model identification more important than simply choosing any 15-inch tire.
Which Tire Size Is Right for The 1979 Dodge Magnum XE
Three tire sizes apply to the 1979 Dodge Magnum XE, and they vary by sub-model rather than by construction or wheel diameter. All use radial construction on a 15-inch rim, so the key step is identifying whether the car is the w/318 Eng. or w/360 Eng. version before choosing a tire. Once the correct fitment is confirmed, the decision becomes selecting the right vintage alphanumeric radial size for the car’s intended look and road use.
FR78-15 is a vintage alphanumeric radial size in which the letter code identifies the tire’s size class, the 78 designates its profile family, and the 15 denotes a 15-inch rim. On the 1979 Dodge Magnum XE, this is a radial fitment rather than a bias-ply size, which keeps the discussion focused on matching the correct radial specification to the car. Buyers looking at FR78-15 should confirm that their Magnum XE is one of the configurations that uses it. That check matters especially on cars that may have had wheels, trim combinations, or drivetrain components changed over time.
GR78-15 is also a vintage alphanumeric radial, with the letter indicating the size class, the 78 marking the profile family, and the 15 confirming a 15-inch wheel. This size is especially important because it appears across both covered Magnum XE engine variants, making it a common fitment point within the 1979 range. Even so, it should not be treated as universal without checking the exact sub-model and wheel setup on the car. For many owners, GR78-15 becomes the practical middle ground to evaluate when confirming what is already mounted or restoring a period-style stance.
HR78-15 follows the same vintage alphanumeric radial system, with the size class carried by the letter, the 78 representing the profile family, and the 15 identifying the rim diameter. For the 1979 Dodge Magnum XE, this size is tied to specific configurations rather than the full model line, so it is best approached as a fitment that requires exact sub-model confirmation. Because it remains a radial tire in the same 15-inch family, the main question is not construction change but whether the car was equipped for this larger size. That makes existing wheel and clearance checks especially worthwhile on modified or long-stored cars.
Sub-model fitment matters on the 1979 Dodge Magnum XE because tire sizes overlap, but they do not stay identical across both engine versions. Checking whether the car is the w/318 Eng. or w/360 Eng. model is the clearest way to narrow the correct 15-inch radial fitment before comparing tire choices.
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1979 Dodge Magnum XE w/318 Eng.
The 1979 Dodge Magnum XE w/318 Eng. uses vintage alphanumeric radial sizing in FR78-15 or GR78-15. That gives the owner a straightforward radial fitment path, but it still makes sense to confirm the actual wheel setup on the car before settling on one size.
The 1979 Dodge Magnum XE w/360 Eng. uses GR78-15 or HR78-15 vintage alphanumeric radial tires. For tire selection, that means confirming whether the car is set up for the shared GR78-15 fitment or the larger HR78-15 size before focusing on appearance and road-use priorities.
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 1979 Dodge Magnum XE’s three radial tire sizes, 15-inch rim fitment, sub-model differences, and the practical checks that matter before putting a collector-era personal-luxury coupe back on the road.
Tire Size & Fitment
What tire size fits a 1979 Dodge Magnum XE?
The 1979 Dodge Magnum XE uses three vintage alphanumeric radial sizes: FR78-15, GR78-15, and HR78-15. The correct choice depends on the exact sub-model. The w/318 Eng. version uses FR78-15 or GR78-15, while the w/360 Eng. version uses GR78-15 or HR78-15.
That means the first step is confirming which engine-based Magnum XE configuration is in front of you rather than choosing by wheel diameter alone. Since all three sizes are 15-inch radials, the real fitment question is which size range matches the car’s original setup, current wheels, and available clearance.
What size rim does a 1979 Dodge Magnum XE use?
Each supported tire size for the 1979 Dodge Magnum XE uses a 15-inch rim. FR78-15, GR78-15, and HR78-15 all share that same rim diameter, so there is no split here between 14-inch and 15-inch applications or between different wheel diameters by sub-model.
Even with a common rim diameter, wheel verification still matters because a 15-inch tire can be mounted on different wheel widths, and many older cars have changed wheels over the years. Confirming the actual wheel dimensions on the car helps avoid choosing a size that looks right on paper but does not suit the current setup.
Do all 1979 Dodge Magnum XE sub-models use the same tire size?
No. The 1979 Dodge Magnum XE sub-models share some overlap, but they do not use one single tire size across the board. The w/318 Eng. model uses FR78-15 or GR78-15, while the w/360 Eng. model uses GR78-15 or HR78-15.
GR78-15 is the shared size, but the smaller FR78-15 and larger HR78-15 are tied to different engine configurations. That overlap can create confusion when a car has replacement wheels or tires already installed, so checking the sub-model first is the best way to narrow the correct radial size before comparing tires.
Choosing the Right Tire
What should I consider when choosing a 1979 Dodge Magnum XE tire?
Start with the correct size for the exact sub-model, since the 1979 Dodge Magnum XE can use FR78-15, GR78-15, or HR78-15 depending on whether it is the w/318 Eng. or w/360 Eng. version. All of these are vintage alphanumeric radials for a 15-inch rim, so size accuracy comes before anything else.
After that, focus on how the car will be used and how closely the tire should suit a period-style presentation. A Magnum XE kept near original specification may call for a more restoration-oriented choice, while a driver car still benefits from careful wheel, clearance, and overall setup checks before settling on one of the supported radial sizes.
How do I choose between the available FR78-15, GR78-15, and HR78-15 tires for a 1979 Dodge Magnum XE?
The first separator is sub-model fitment. FR78-15 belongs with the w/318 Eng. range, HR78-15 belongs with the w/360 Eng. range, and GR78-15 overlaps both. That makes GR78-15 the shared fitment point, while the other two sizes should only be considered when they match the car’s exact configuration.
Once the sub-model is confirmed, compare the tire to the actual wheels and to the overall look you want from the car. A long-stored Magnum XE may already be wearing a replacement size, so it helps to inspect the wheel and existing tire markings carefully before assuming the current setup reflects the right fitment.
What rim-fitment details should I compare when choosing 1979 Dodge Magnum XE tires?
All supported 1979 Dodge Magnum XE tire sizes are built for 15-inch rims, but rim diameter is only part of the picture. Wheel width, actual wheel type, and the car’s current setup can all influence how well a given FR78-15, GR78-15, or HR78-15 tire suits the vehicle.
That is especially important on collector cars that may have changed hands several times. Measuring the wheels on the car and checking for suspension, steering, or fender interference helps keep the tire decision grounded in the real vehicle rather than in assumptions about what should be there.
Restoration & Appearance
Which tire should I choose for a period-style 1979 Dodge Magnum XE?
A period-style starting point for a 1979 Dodge Magnum XE is the correct vintage alphanumeric radial size for the exact sub-model: FR78-15 or GR78-15 on the w/318 Eng. version, and GR78-15 or HR78-15 on the w/360 Eng. version. Staying within those supported radial fitments preserves the right general sizing language for the car’s late-1970s character.
Owners aiming for a more exact restoration should still compare the car against historical references specific to that vehicle. Build documentation, marque-club guidance, and surviving original examples can help narrow the most appropriate presentation, while the tire choice itself should remain anchored to the right supported size and wheel setup.
Does correct tire fitment matter for a 1979 Dodge Magnum XE restoration?
Yes. Correct tire fitment shapes both the appearance and the stance of a restored 1979 Dodge Magnum XE, and this model does not use one universal size across every version. Matching the tire to the proper FR78-15, GR78-15, or HR78-15 application keeps the restoration closer to the car’s intended proportions.
That matters even more when the car has been modified or has worn replacement tires for years. A restoration-minded owner should verify the sub-model, confirm the 15-inch wheel setup, and inspect the car’s present ride height and clearance so the finished result looks coherent rather than merely using any tire that mounts.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1979 Dodge Magnum XE?
Yes. Even though the 1979 Dodge Magnum XE uses supported 15-inch radial sizes, modifications can change whether FR78-15, GR78-15, or HR78-15 remains appropriate on the actual car. Aftermarket wheels, suspension changes, altered ride height, or bodywork repairs can all affect the tire’s relationship to the wheel opening and steering path.
A Magnum XE that has been lowered, fitted with different wheels, or rebuilt with non-original parts deserves a fresh fitment check before new tires are chosen. Looking at wheel dimensions, steering travel, and fender clearance is especially worthwhile when moving between the smaller and larger supported size ranges.
What should I inspect before driving a 1979 Dodge Magnum XE on new tires?
Before road use, inspect the wheels, valve stems, lug hardware, and the tire-to-body clearance at straight-ahead and turned positions. It is also wise to check for uneven suspension wear, loose steering components, and any sign that the car has old alignment issues that could affect a fresh set of FR78-15, GR78-15, or HR78-15 tires.
Collector cars often spend long periods parked, so the rest of the chassis deserves attention along with the tires. Confirming proper inflation, looking for fluid leaks that could reach the rubber, and taking a short shakedown drive before extended use can help reveal issues before the Magnum XE is driven at speed.
How should tires on a collector 1979 Dodge Magnum XE be maintained?
Tires on a collector 1979 Dodge Magnum XE should be checked regularly for inflation, tread condition, sidewall cracking, cuts, bulges, and signs of slow air loss. Because these cars are often driven less than modern daily transportation, tire condition can change with age and storage time even when mileage stays low.
Parking on a clean surface, avoiding prolonged exposure to heat and sunlight, and moving the car periodically can help reduce storage-related stress. It also makes sense to inspect the tires before each outing rather than relying on last season’s condition, especially on a car that may sit for weeks between drives.
