The 1958 Opel Kapitan came from a period when European family and executive cars were balancing postwar practicality with a more streamlined, American-influenced sense of style. That makes tire choice especially important, because the car’s stance and road manners are closely tied to the size and construction you put under it. For the 1958 Opel Kapitan, the core fitment centers on 13-inch tires in either 6.70-13 bias-ply or 175R13 radial form. That gives owners a meaningful decision between traditional bias-ply presentation and a radial option in the same wheel diameter. The right choice depends on whether the priority is restoration character, road-use behavior, or confirming the car’s current wheel and suspension setup.
Which Tire Size Is Right for The 1958 Opel Kapitan
The 1958 Opel Kapitan uses two primary tire sizes, and the difference is mainly construction rather than wheel diameter. Both sizes fit a 13-inch rim, but one is a traditional 6.70-13 bias-ply and the other is a 175R13 radial, so the first step is deciding whether the car is being kept in a period-style bias-ply setup or run on a radial configuration.
175R13 is a Euro-metric radial size in which 175 identifies the nominal section width in millimeters, the R indicates radial construction, and 13 is the wheel diameter in inches. On a 1958 Opel Kapitan, this size represents the radial fitment option while keeping the same 13-inch rim diameter. The radial format is useful for owners who want to stay with a period-compatible wheel size while considering a different construction style from the older numeric bias-ply setup. It is a size worth evaluating carefully if the car has already been updated or if road-use priorities differ from a restoration-focused appearance.
6.70-13 is a numeric bias-ply size, with 6.70 representing the nominal section width in inches and 13 indicating the rim diameter. For the 1958 Opel Kapitan, this is the traditional bias-ply fitment and it suits buyers who want to preserve the visual character and construction style associated with the era. Numeric bias-ply sizing is familiar on many mid-century cars, and it typically appeals to restoration-oriented owners looking for a more traditional tire presentation. It deserves a close look when maintaining the car’s original-style stance matters as much as basic fitment.
Fitment is straightforward for the covered 1958 Opel Kapitan sub-model, since the same two 13-inch tire size paths appear here. Checking the exact sub-model still matters because the real choice is whether the car is staying with 6.70-13 bias-ply construction or using 175R13 radial tires.
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1958 Opel Kapitan Base
The 1958 Opel Kapitan Base can be fitted with either 175R13 radial tires or 6.70-13 bias-ply tires on 13-inch wheels. That means selection is less about trim-level differences and more about choosing the construction style that best matches the car’s appearance goals, wheel setup, and intended 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.
Frequently Asked Questions
These common 1958 Opel Kapitan tire questions focus on the two applicable 13-inch sizes, the difference between radial and bias-ply construction, and the fitment checks that matter before putting the car back on the road.
Tire Size & Fitment
What tire size fits a 1958 Opel Kapitan?
The 1958 Opel Kapitan uses two primary tire sizes: 175R13 in radial construction and 6.70-13 in bias-ply construction. Both are 13-inch fitments, so the main difference is not wheel diameter but the tire sizing system and construction style chosen for the car.
That means the first decision is whether the Kapitan is staying with a traditional bias-ply setup or using a radial. Once that is settled, it is smart to confirm the actual wheel diameter on the car and inspect for prior modifications, since older collector vehicles are sometimes fitted with non-original wheels or suspension changes over time.
What size rim does a 1958 Opel Kapitan use?
The applicable tire sizes for a 1958 Opel Kapitan both use a 13-inch rim diameter. That includes the 175R13 radial option and the 6.70-13 bias-ply option, so the wheel diameter remains consistent even though the tire construction and size notation are different.
Rim diameter is only one part of the fitment picture on an older car. Wheel width, bead-seat condition, and any past wheel changes should also be checked before mounting tires, especially if the Kapitan has been stored for long periods or if the current wheels are not known to be the car’s original-style setup.
Does the 1958 Opel Kapitan Base use the same tire size?
Yes. The 1958 Opel Kapitan Base uses the same two primary tire size paths found on the core model fitment: 175R13 in radial construction and 6.70-13 in bias-ply construction. The sub-model does not introduce a separate rim diameter or a different primary size family.
That keeps the choice focused on construction and appearance rather than trim-specific fitment differences. A buyer still needs to confirm what is actually on the car today, because a Base model may have been changed over the years, and that can affect which tire size and construction make the most sense now.
Bias-Ply & Radial Options
Is 6.70-13 a bias-ply or radial tire for the 1958 Opel Kapitan?
On the 1958 Opel Kapitan, 6.70-13 is a bias-ply tire size. It uses the older numeric sizing system common to mid-century vehicles, where the first number gives a nominal section width in inches and the final number identifies the 13-inch rim diameter.
That makes 6.70-13 the more traditional construction choice for owners who want a period-style presentation. Before choosing it, the practical step is to make sure the Kapitan is still set up around that style of tire and that the wheel condition, suspension, and clearances all support the intended use of the car.
Should I use bias-ply or radial tires on a 1958 Opel Kapitan?
A 1958 Opel Kapitan can be run with either 6.70-13 bias-ply tires or 175R13 radial tires, both on 13-inch rims. The decision comes down to whether the car is being kept closer to a traditional mid-century tire presentation or set up around a radial construction in the same wheel diameter.
Bias-ply tires usually appeal more to restoration-minded owners, while a radial choice may suit a car that is already configured around radial use. The important step is to evaluate the current wheels and the vehicle’s actual setup rather than changing construction casually, especially on an older car with an unknown service history.
What should I check before converting my 1958 Opel Kapitan from bias-ply to radial tires?
A conversion on a 1958 Opel Kapitan starts with confirming the wheel diameter, which remains 13 inches, and verifying that the car is being moved from 6.70-13 bias-ply fitment to 175R13 radial fitment. The size change should be treated as a construction and fitment decision, not as an automatic interchange.
Wheel width, wheel condition, steering clearance, suspension health, and body clearance all deserve attention before the switch. It also helps to inspect for previous modifications, because an older Kapitan may no longer sit or steer exactly as it did originally, and that can affect how a radial setup behaves in practice.
Choosing the Right Tire
What should I consider when choosing a tire for a 1958 Opel Kapitan?
Start with the correct primary fitment path for the 1958 Opel Kapitan: 6.70-13 if the car is staying with bias-ply construction, or 175R13 if it is using a radial setup. Both use a 13-inch wheel, so the main choice is the tire construction and sizing style that best matches the car.
After that, think about how the Kapitan will actually be used. A restoration-oriented car may lean toward the traditional bias-ply presentation, while a driver may be evaluated around the radial option. Either way, wheel condition, current suspension setup, and the vehicle’s existing stance should all be checked before finalizing the selection.
How do I choose between the available 13-inch tire sizes for a 1958 Opel Kapitan?
Choosing between the available 13-inch sizes on a 1958 Opel Kapitan means deciding between two different tire philosophies. The 6.70-13 size is the traditional numeric bias-ply fitment, while 175R13 is the radial fitment in a Euro-metric format, both intended for the same rim diameter.
That choice should reflect the car’s present setup and the owner’s priorities rather than modern habit alone. A Kapitan being preserved for period appearance may call for a different answer than one being prepared for regular driving, and any past changes to wheels, suspension height, or alignment should be considered before selecting one path.
What tire construction is right for a 1958 Opel Kapitan?
The right construction for a 1958 Opel Kapitan depends on the kind of car it is today. The primary options are 6.70-13 bias-ply and 175R13 radial, so the decision is whether to stay with the more traditional numeric bias-ply format or use the radial size offered for the same 13-inch wheel diameter.
Construction choice affects more than the label on the sidewall. It should be considered alongside the car’s restoration goals, how often it is driven, and whether the wheels and suspension are already set up around one type. Older collector cars often have mixed histories, so confirming the actual configuration is worth the time.
Restoration & Appearance
Which tire should I choose for a period-style 1958 Opel Kapitan?
For a period-style 1958 Opel Kapitan, 6.70-13 bias-ply is the natural starting point because it uses the traditional numeric bias-ply format associated with cars from the era. The 175R13 radial option keeps the same 13-inch rim diameter, but it represents a different construction and a more modern sizing convention.
That does not make one choice universally right for every restoration. A car judged primarily on historical presentation may lead in one direction, while a driver-focused restoration may lead in another. When originality matters at a high level, marque-specific references and restoration documentation are still the best final authority.
How does tire construction affect the appearance of a restored 1958 Opel Kapitan?
Tire construction can noticeably change how a restored 1958 Opel Kapitan presents, even when both options use a 13-inch rim. A 6.70-13 bias-ply keeps the older numeric sizing format and a more traditional mid-century character, while a 175R13 radial brings a different construction language to the car.
For many restorations, appearance is tied to more than simple fit. The tire choice influences how authentic the overall presentation feels beside the body shape, wheel style, and stance. That is why construction should be selected as part of the restoration plan, not treated as a minor detail added at the end.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1958 Opel Kapitan?
Yes. Modifications can affect tire fitment on a 1958 Opel Kapitan even when the intended size is one of the correct 13-inch options. Changes such as aftermarket wheels, altered wheel width, suspension work, or body and fender adjustments can influence how either 175R13 radial or 6.70-13 bias-ply tires sit on the car.
That is why the current setup should be inspected before choosing tires by size alone. Clearance at full steering lock, suspension travel, and wheel condition all matter, especially on a collector car that may have passed through several owners and been changed in ways that are not obvious at first glance.
What should I inspect before driving a 1958 Opel Kapitan on new tires?
Before driving a 1958 Opel Kapitan on new tires, inspect the wheels for damage or corrosion, verify the 13-inch wheel diameter, and make sure the selected construction matches the car’s setup. It is also wise to check alignment condition, steering components, and overall suspension health on a car from this era.
A road-ready inspection should also include tire pressure, valve condition, and a close look at nearby clearance points around the fenders and steering range. On a low-use collector car, dried seals, worn bushings, or uneven ride height can show up only after the car is back in motion, so caution is worthwhile.
How should tires on a collector 1958 Opel Kapitan be maintained?
Tires on a collector 1958 Opel Kapitan should be maintained with regular pressure checks, routine visual inspection, and careful storage habits. Whether the car is running 6.70-13 bias-ply tires or 175R13 radials, sidewall cracking, bulges, cuts, uneven wear, and signs of air loss deserve attention before every meaningful drive.
Long periods of storage can be just as important as mileage on an older vehicle. Keeping the Kapitan away from prolonged sunlight, moisture, and ozone sources helps preserve the tires, and periodic movement can reduce flat spotting concerns. Any tire that shows age-related deterioration should be evaluated before road use continues.
