The 1978 Opel sits in the late-1970s compact European tradition, where light weight, tidy proportions, and responsive road manners made tire choice an important part of how the car feels on the road. For this exact model year, fitment centers on 13-inch radial tires, with 155R13 and 175/70R13 sizes appearing across the covered configurations. That means the key decision is not just diameter, but which size belongs on the specific sub-model and whether a traditional Euro-metric radial or a lower-profile metric radial better matches the car’s setup. Brand choice also matters here, with different series available for owners balancing road use, appearance, and restoration-minded presentation.
Which Tire Size Is Right for The 1978 Opel
The 1978 Opel uses two primary tire sizes, and both are radial designs built for 13-inch rims. The first step is confirming the exact sub-model, because the Coupe & 4 Dr. Sedan can use either 155R13 or 175/70R13, while the Sport Coupe uses 155R13. Once that is settled, the decision becomes choosing the right style of radial tire for the car’s intended appearance and driving use.
155R13 is a Euro-metric radial size in which 155 refers to the nominal section width in millimeters, R identifies radial construction, and 13 is the rim diameter in inches. This format is commonly associated with a traditional metric radial profile and suits the 1978 Opel’s 13-inch wheel fitment. Available choices in this size include Michelin and Dunlop, both in blackwall form, with series such as Michelin XAS-FF and SP Sport Aquajet. It is a useful size for owners who want a more traditional radial presentation on covered Opel configurations that use this fitment.
175/70R13 is a metric radial size where 175 is the nominal section width in millimeters, 70 is the aspect ratio, R denotes radial construction, and 13 is the wheel diameter. On the 1978 Opel, this size appears on the Coupe & 4 Dr. Sedan and represents a more modern stated-profile radial format than 155R13. The available product in this size is an Avon CR6ZZ blackwall radial. It is the size to evaluate when the car already uses this fitment and the wheel setup matches the intended 13-inch radial application.
Sub-model fitment matters on the 1978 Opel because tire choice is not completely uniform across the range. The Coupe & 4 Dr. Sedan can be matched with more than one radial size, while the Sport Coupe stays with a single fitment, so identifying the exact version should come before comparing tires.
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1978 Opel Coupe & 4 Dr. Sedan
The 1978 Opel Coupe & 4 Dr. Sedan uses radial 13-inch tire fitments and can be associated with either 155R13 or 175/70R13. That makes this the sub-model where wheel setup and current tire sizing deserve a careful look before selecting between a traditional Euro-metric radial and a lower-profile metric radial.
The 1978 Opel Sport Coupe uses a single primary radial fitment in 155R13 on a 13-inch rim. Tire selection here is more straightforward, with the main choice shifting from size to brand, tire series, and whether the owner wants a more traditional roadgoing radial character.
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 Opel Tires for sale
Available 1978 Opel tires center on radial 13-inch fitments from Michelin, Dunlop, and Avon. The current choices are blackwall tires across distinct series, including Michelin XAS-FF, SP Sport Aquajet, and CR6ZZ, with differences in size, rim-width compatibility, and overall tire character.
Common questions for the 1978 Opel usually come down to identifying the right 13-inch radial size, understanding how sub-model fitment differs, and comparing available tire series, brands, and maintenance checks before regular road use.
Tire Size & Fitment
What tire size fits a 1978 Opel?
The 1978 Opel uses radial tires in two primary sizes: 155R13 and 175/70R13. Fitment depends on the sub-model, with the Coupe & 4 Dr. Sedan associated with both sizes and the Sport Coupe using 155R13. Both sizes are built for 13-inch rims.
The practical step is to confirm the exact sub-model and then verify the wheel and tire size already on the car. On older vehicles, wheel changes over time are common, so matching the tire to the actual 13-inch wheel setup is just as important as matching the year and model.
What size rim does a 1978 Opel use?
The 1978 Opel uses a 13-inch rim with its primary tire fitments. Both 155R13 and 175/70R13 are 13-inch radial sizes, so the rim diameter remains the same even though the tire sizing format changes between the two fitments.
Rim diameter is only part of the picture, especially if the car has been updated with different wheels over the years. It also helps to confirm wheel width before choosing among available tires, since individual products can carry different rim-width ranges within the same 13-inch diameter.
Do all 1978 Opel sub-models use the same tire size?
No. The 1978 Opel Coupe & 4 Dr. Sedan can use 155R13 or 175/70R13, while the 1978 Opel Sport Coupe uses 155R13. That means tire size is not completely uniform across the covered sub-models, even though all of them use radial construction on 13-inch rims.
That difference matters because a buyer should not assume every 1978 Opel uses the same tire simply because the wheel diameter matches. The safest approach is to identify the exact sub-model first, then confirm the current wheel and tire setup before comparing available replacements.
Choosing the Right Tire
What should I consider when choosing a tire for a 1978 Opel?
Start with the correct size for the exact sub-model, since the 1978 Opel uses either 155R13 or 175/70R13 depending on configuration. From there, compare radial construction details, rim-width compatibility where stated, and the tire series available in that specific size.
Appearance and use also shape the decision. A traditional Euro-metric radial such as 155R13 gives a different sizing presentation than 175/70R13, while brand and series choices can matter to owners focused on restoration-minded looks, weekend driving, or maintaining a particular period character.
What sidewall styles are available for 1978 Opel tires?
The available tires for the 1978 Opel are offered in blackwall form. That applies across the current products in 155R13 and 175/70R13, including the Michelin, Dunlop, and Avon options associated with these 13-inch radial fitments.
Since sidewall treatment is consistent here, the real visual differences come more from tire series and sizing format than from whitewall or stripe choices. Owners trying to keep a clean late-1970s European appearance will usually focus on selecting the correct size first and then choosing the blackwall radial that best suits the car’s intended use.
What brands offer tires for the 1978 Opel?
Michelin, Dunlop, and Avon offer tires for the 1978 Opel within the applicable 13-inch radial sizes. Michelin and Dunlop appear in 155R13, while Avon is available in 175/70R13, giving buyers a mix of brands across the two fitment paths.
Brand choice should be made after the size is settled, not before. Once the correct fitment is confirmed, compare the available series, the intended look of the tire, and any published rim-width range or load information that helps match the tire to the wheel and the way the car will be driven.
Restoration & Appearance
Which tire should I choose for a period-style 1978 Opel?
A period-style approach starts with the correct radial size for the exact 1978 Opel sub-model. The two relevant fitments are 155R13 and 175/70R13, both on 13-inch rims, with 155R13 offering a more traditional Euro-metric sizing presentation.
For a restoration-oriented look, it helps to match not just the diameter but also the visual character of the tire to the car’s era. Owners seeking exact historical accuracy should still compare the car against marque references, original literature, or trusted club guidance before settling on a final size and tire series.
How does tire construction affect the appearance of a restored 1978 Opel?
Construction changes are not the main appearance issue on a 1978 Opel because the primary fitments here are already radial tires. The visual difference comes more from the size format itself, such as 155R13 versus 175/70R13, along with the tire series used within those fitments.
That means a restoration-minded owner should pay close attention to profile and overall presentation rather than looking for a bias-ply versus radial decision. Keeping the correct size family on the car usually has a bigger impact on period feel than switching between brands that share the same blackwall sidewall style.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1978 Opel?
Yes. Even though the 1978 Opel uses 13-inch radial tire sizes, aftermarket wheels, suspension changes, lowering, or body alterations can change what actually clears the car. A modified setup may no longer match the wheel width, tire profile, or clearance assumptions of the original fitment range.
That is why the wheel and car should be inspected as they sit today before choosing between 155R13 and 175/70R13. Checking wheel width, steering clearance, fender clearance, and suspension condition can prevent ordering a tire that matches the model year but not the vehicle’s current configuration.
What should I inspect before driving a 1978 Opel on new tires?
Before regular road use, inspect the wheels for damage, confirm the rim diameter and width, and make sure the tire size on the car matches the intended fitment. It also helps to check wheel hardware, valve stems, inflation pressure, and basic alignment condition so the new tires start out on a sound foundation.
An older Opel can sit for long periods, so it is also wise to look over suspension bushings, steering components, and brake condition before any meaningful drive. A fresh set of tires performs best when the rest of the contact and control system is equally ready for road use.
How often should tires on a 1978 Opel be inspected?
Tires on a 1978 Opel should be inspected regularly, especially if the car is collector-owned or driven only occasionally. Look for air loss, uneven wear, sidewall cracking, bulges, cuts, and any signs that the tires have aged out of safe road service even if tread depth still appears acceptable.
Cars that spend long periods parked deserve extra attention because time and storage conditions can matter as much as mileage. A quick inspection before each drive, plus a more thorough check during routine maintenance, helps catch problems early and keeps the 13-inch radial setup ready for dependable use.
