The 1978 Pontiac Grand LeMans came from an era when midsize American cars balanced personal-luxury styling with everyday road manners, and tire choice played a big part in how that character was presented. For this exact model, fitment stays within 14-inch radial sizes, but the correct selection depends on engine-specific configuration. The 6 Cyl. versions use 185/75R14 or 195/75R14, while 8 Cyl. versions use 195/75R14 or 205/70R14, giving owners a mix of whitewall, redline, raised white letter, and blackwall options. The key is matching the tire to the car's actual sub-model, wheel setup, and the appearance or driving feel you want to preserve.
Which Tire Size Is Right for The 1978 Pontiac Grand LeMans
Three radial tire sizes apply to the 1978 Pontiac Grand LeMans, and the right one depends on the exact engine-specific sub-model rather than a change in rim diameter, since all three use a 14-inch wheel. The first step is confirming whether the car is a 6 Cyl. or 8 Cyl. version, then matching that setup to the correct size and the sidewall style or tire series that best suits the car.
185/75R14 is a metric radial size in which 185 refers to the nominal section width in millimeters, 75 is the aspect ratio, R indicates radial construction, and 14 is the rim diameter in inches. On the 1978 Pontiac Grand LeMans, this size is used on certain 6 Cyl. applications and keeps the fitment within a traditional 14-inch radial format. Available choices center on narrow whitewall styling from brands such as Tornel, Maxxis, and Travelstar across several classic-style series. It is a useful size to evaluate when maintaining the proper fitment range for a 6 Cyl. car with stock-type wheel diameter.
195/75R14 follows the same metric radial sizing system, with a 195-millimeter nominal width, a 75-series profile, radial construction, and a 14-inch rim. This size appears across both 6 Cyl. and 8 Cyl. Grand LeMans applications, making it the shared fitment point within the model range. Product choice is broader here, including wide whitewall and narrow whitewall options from Coker Classic, Tornel, Maxxis, and Travelstar in series such as Star Series, Coker Classic Radial, Tornel Classic, Classic Whitewall MA-1, and UN106. It is the size to consider when your car falls into the overlap between sub-model fitments and appearance choice becomes the next decision.
205/70R14 is a metric radial size with a 205-millimeter nominal section width, a 70-series profile, radial construction, and a 14-inch rim diameter. On the 1978 Pontiac Grand LeMans, this size is used on certain 8 Cyl. applications and brings the widest primary fitment of the three listed sizes. Available options include narrow whitewall, raised white letter, redline, dual redline, and blackwall treatments from Maxxis, BFGoodrich, and Michelin in series such as Classic Whitewall MA-1, Radial TA, Silvertown Radial, and Michelin XWX. This size deserves careful attention when the goal is matching an 8 Cyl. car to the right look as well as the right dimensions.
Sub-model fitment matters on the 1978 Pontiac Grand LeMans because the tire-size range changes with engine configuration. Both covered versions use 14-inch radial tires, but the overlap is not identical, so confirming the exact sub-model helps narrow the correct choices before comparing brands or sidewall styles.
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1978 Pontiac Grand LeMans 6 Cyl.
The 1978 Pontiac Grand LeMans 6 Cyl. uses radial fitments in the 185/75R14 to 195/75R14 range on 14-inch wheels. That makes the next decision less about construction and more about selecting the right size for the car's current wheel setup and the whitewall presentation you want.
The 1978 Pontiac Grand LeMans 8 Cyl. uses radial fitments in the 195/75R14 to 205/70R14 range on 14-inch wheels. That opens the door to a broader appearance spread, including whitewall, redline, raised white letter, and blackwall options once the wheel and tire size are confirmed.
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 1978 Pontiac Grand LeMans Tires for Sale
Available 14-inch radial choices for the 1978 Pontiac Grand LeMans span Tornel, Maxxis, Travelstar, Coker Classic, BFGoodrich, and Michelin. Depending on size, buyers can compare narrow whitewall, wide whitewall, redline, dual redline, raised white letter, and blackwall designs across several classic-oriented tire series.
Common questions for the 1978 Pontiac Grand LeMans usually center on which radial size fits a specific sub-model, whether 14-inch wheels are shared across the range, and how to choose among whitewall, redline, raised white letter, and blackwall tire options.
Tire Size & Fitment
What tire size fits a 1978 Pontiac Grand LeMans?
The 1978 Pontiac Grand LeMans uses three primary radial tire sizes: 185/75R14, 195/75R14, and 205/70R14. The 6 Cyl. version uses 185/75R14 or 195/75R14, while the 8 Cyl. version uses 195/75R14 or 205/70R14.
That means the correct choice starts with identifying the exact sub-model, not just the year and model name. Since all three sizes fit 14-inch wheels, the next check is the actual wheel and tire setup on the car now, especially if it has replacement wheels or has been changed from its earlier fitment pattern.
What size rim does a 1978 Pontiac Grand LeMans use?
The covered tire fitments for a 1978 Pontiac Grand LeMans all use a 14-inch rim diameter. That applies across 185/75R14, 195/75R14, and 205/70R14, so the wheel diameter stays consistent even though the tire sizes vary by sub-model.
Rim diameter is only the first check, because wheel width still matters when comparing actual tire options. Before choosing a replacement tire, confirm the car still has 14-inch wheels and verify the wheel width against the tire's approved range, especially if the Grand LeMans has aftermarket wheels or mixed wheel sets.
Do all 1978 Pontiac Grand LeMans sub-models use the same tire size?
No, the 1978 Pontiac Grand LeMans does not use one universal tire size across all covered sub-models. The 6 Cyl. version uses 185/75R14 or 195/75R14, while the 8 Cyl. version uses 195/75R14 or 205/70R14, so 195/75R14 is shared but the outer size range changes.
That shared middle size can make the fitment look simpler than it is, but the sub-model still matters. Owners should confirm the exact engine-specific version, then compare the wheel width and the tire already on the car before moving to a different listed size within the 14-inch fitment family.
Choosing the Right Tire
What should I consider when choosing a tire for a 1978 Pontiac Grand LeMans?
Start with the correct primary size for the exact sub-model, since the 1978 Pontiac Grand LeMans can use 185/75R14, 195/75R14, or 205/70R14 depending on configuration. From there, the important choices are wheel-width compatibility, sidewall style, tire series, load capacity, and the kind of road use or visual presentation the car is meant to have.
A whitewall tire can support a more traditional late-1970s look, while redline, dual redline, raised white letter, or blackwall choices change the car's visual character considerably. It also helps to compare the actual wheel on the car and avoid assuming that any listed 14-inch size is appropriate without checking the current setup.
What sidewall styles are available for 1978 Pontiac Grand LeMans tires?
Sidewall choices for the 1978 Pontiac Grand LeMans include narrow whitewall, wide whitewall, redline, dual redline, raised white letter, and blackwall, depending on the tire size selected. The broadest appearance range appears in 205/70R14, while 185/75R14 and 195/75R14 focus more heavily on whitewall presentations.
That makes sidewall style an important part of selecting the tire after the correct size is confirmed. A buyer restoring a more formal look may lean toward whitewalls, while a sportier late-1970s presentation may point toward redline or raised white letter styling, provided the chosen size also matches the car's sub-model and wheel.
What brands offer tires for the 1978 Pontiac Grand LeMans?
Tires for the 1978 Pontiac Grand LeMans are available from Tornel, Maxxis, Travelstar, Coker Classic, BFGoodrich, and Michelin across the applicable 14-inch radial sizes. Brand availability varies by size, so the selection becomes broader or narrower depending on whether the car uses 185/75R14, 195/75R14, or 205/70R14.
Brand choice should come after fitment confirmation, not before it. Once the right size is established, compare each option by sidewall style, tire series, rim-width specification, and load capacity at the stated pressure where that information is given, since those differences often matter more than the name on the sidewall alone.
Restoration & Appearance
Which tire should I choose for a period-style 1978 Pontiac Grand LeMans?
A period-style 1978 Pontiac Grand LeMans tire choice starts with the correct size for the sub-model, then moves to the visual character of the tire. Whitewall radials are widely available in the covered sizes, while 205/70R14 also opens the door to redline, dual redline, raised white letter, and blackwall presentations.
The best period-style direction depends on how the car is being finished rather than on one universal answer for every Grand LeMans. Owners aiming for a restoration-oriented appearance should compare old photos, surviving cars, sales literature, or marque-specific references before settling on a stripe or letter treatment.
Does correct tire fitment matter for a 1978 Pontiac Grand LeMans restoration?
Correct tire fitment matters on a 1978 Pontiac Grand LeMans restoration because the size affects both the stance of the car and the credibility of the finished look. Using the proper 14-inch radial fitment range for the correct sub-model keeps the restoration grounded in the sizes associated with the car.
Appearance details matter too, since a wide whitewall, narrow whitewall, redline, or raised white letter sidewall can change the car's personality quickly. Even when the tire remains within the correct fitment family, it is worth checking wheel width and the overall presentation so the finished car does not look visually mismatched.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1978 Pontiac Grand LeMans?
Yes, modifications can affect tire fitment on a 1978 Pontiac Grand LeMans even when the tire size falls within the normal 14-inch range. Wheel-width changes, aftermarket wheel designs, suspension alterations, ride-height changes, or body and steering-clearance differences can all influence whether a listed size remains appropriate on the car.
A Grand LeMans with replacement wheels should be measured rather than judged by the original application alone. Checking wheel width, backspacing or offset where relevant, and clearance at full steering lock and suspension movement helps prevent selecting a tire that matches the cataloged size but conflicts with the modified setup.
What should I inspect before driving a 1978 Pontiac Grand LeMans on new tires?
Before driving a 1978 Pontiac Grand LeMans on new tires, inspect the wheels for correct diameter and sound condition, then confirm proper inflation, lug hardware, and basic clearance around the suspension, steering, and fenders. It is also wise to verify that all four tires match the intended size and construction for the car's setup.
A short test drive should be used to catch rubbing, pulling, or unusual vibration before putting the car into regular service. Collector cars often spend long periods parked, so checking alignment condition, brake drag, and any age-related wear elsewhere in the chassis can be just as important as the new tires themselves.
How should tires on a collector 1978 Pontiac Grand LeMans be maintained?
Tires on a collector 1978 Pontiac Grand LeMans should be maintained with regular pressure checks, visual inspection, and careful storage habits. Sidewall cracking, bulges, cuts, irregular tread wear, and slow air loss deserve attention even when the car is driven only occasionally, because age and storage conditions matter on low-mileage collector vehicles.
Parking away from prolonged sunlight, heat, moisture, and ozone sources helps preserve the tire over time. It also helps to move the car periodically or avoid leaving it loaded in one position for long stretches, then inspect the tires again before road use if the Grand LeMans has been stored for an extended period.
