1970 Opel Tires

The 1970 Opel GT uses either a 165R13 radial tire or a 560-13 bias-ply tire. Both sizes are associated with 13-inch rims, but they represent different construction types and different approaches to replacing the tires on the car.

Choosing between them starts with the car's actual wheel setup and the owner's goal for the vehicle. A period-style restoration may stay with 560-13 bias-ply tires, while a car already set up for radials may use 165R13. Wheel width, tire clearance, and the construction already on the car should all be checked before making a change.

The applicable tire sizes for the 1970 Opel use a 13-inch rim diameter. That applies to both the 165R13 radial fitment and the 560-13 bias-ply fitment, so wheel diameter remains consistent even though the tire sizing systems are different.

Rim diameter is only one part of the fitment picture. Tire choice should also account for wheel width, since the available products do not all cover the same width range. A car with replacement wheels or a long ownership history should have the wheels measured rather than assuming the original setup is still in place.

A 560-13 is a numeric bias-ply tire size. The 560 indicates a nominal section width of about 5.60 inches, and the 13 identifies the rim diameter. On the 1970 Opel GT, it represents the bias-ply fitment rather than a radial format.

That matters because a 560-13 is selected differently than a modern metric radial size. Buyers usually focus on period-style appearance, whitewall treatment, and wheel compatibility within the correct 13-inch fitment. Anyone considering a radial alternative should compare the wheel width and the car's actual tire-to-body clearance before changing construction.

On the 1970 Opel GT, 560-13 is a bias-ply tire size. It uses the older numeric sizing format and is available in classic bias-ply constructions from brands such as BFGoodrich and Firestone, with whitewall options that suit a more traditional appearance.

That makes 560-13 the right starting point for buyers who want a vintage-style presentation and a period-oriented setup. It should not be confused with the 165R13 radial fitment, even though both use 13-inch rims. Construction choice affects appearance, wheel-width requirements, and the overall character of the tire package.

Radial equivalents for 560-13 include 155R13, P155/75R13, and P155/70R13. Those options cover an 80-series metric radial format, a 75-series P-metric radial, and a 70-series P-metric radial, giving several ways to consider a radial alternative to the original bias-ply size.

The recommended rim-width range for those equivalents is 4 to 5 inches, which makes wheel measurement especially important before converting. Equivalent sizing is a useful guide, but it does not replace checking the car's actual wheels, tire clearance, and overall proportions. A lower-profile alternative should be evaluated carefully on a small vintage chassis.

Start by confirming the wheel diameter and width on the car, then compare the intended radial size against the current bias-ply setup. A 560-13 bias-ply can be evaluated against radial equivalents such as 155R13, P155/75R13, or P155/70R13, but the wheel still has to suit the tire.

Clearance at the fenders and steering should be inspected next, especially if the Opel has non-stock wheels, altered ride height, or suspension wear. Construction changes can also affect the overall feel and appearance of the car. A careful conversion is less about finding any 13-inch radial and more about matching the wheel and vehicle setup correctly.

The main decision is whether the car should use the 560-13 bias-ply fitment or the 165R13 radial fitment. That choice shapes everything else, including sidewall appearance, brand options, tire series, and the wheel-width range that the tire is intended to work with.

After size and construction are settled, compare the way the car will be used. A restoration-oriented Opel may lean toward classic bias-ply styling, while a road-driven car may point toward a radial setup. It also helps to compare product details such as sidewall style, maximum load figures where stated, and the actual wheel dimensions on the vehicle.

Sidewall choice depends on the tire size and construction selected. The 165R13 radial options are blackwall tires, while the 560-13 bias-ply options include narrow whitewall and wide whitewall versions. That creates a clear visual difference between the radial and bias-ply offerings for the Opel GT.

Appearance matters on a small vintage coupe, so sidewall style should be chosen with the car's overall presentation in mind. A blackwall radial gives a more restrained and sporting look, while whitewall bias-ply tires push the car toward a more traditional period-style finish. The right answer depends on the look the owner wants rather than one universally correct choice.

The 1970 Opel has tire options from Michelin and Dunlop in 165R13 radial fitment, along with BFGoodrich and Firestone in 560-13 bias-ply fitment. Those brands are spread across different constructions, tire series, and sidewall presentations rather than duplicating the same product type.

Brand comparison should start with the correct size and construction, not the name on the sidewall alone. Michelin and Dunlop choices stay within the blackwall radial side of the fitment, while BFGoodrich and Firestone cover the whitewall bias-ply side. Once that is narrowed down, wheel-width compatibility and the intended look of the car become the deciding factors.

A period-style 1970 Opel restoration will often begin with the 560-13 bias-ply size, since it keeps the vintage numeric sizing format and offers traditional sidewall treatments. BFGoodrich and Firestone bias-ply choices in this size give the buyer a more classic visual starting point than the blackwall radial alternatives.

That does not automatically make every 560-13 tire historically exact for every car, so owners pursuing strict originality should compare the car against marque references and restoration documentation. For many buyers, though, the right period-style result comes from keeping the proper size and construction while selecting the whitewall treatment that best suits the car's finished appearance.

Construction changes the look of the car as much as the road feel. A 560-13 bias-ply tire gives the 1970 Opel GT a more traditional vintage presentation, especially with narrow whitewall or wide whitewall styling, while a 165R13 radial presents a cleaner blackwall European touring look.

That visual difference matters on a compact car where the tire and wheel package is easy to notice. Buyers restoring for show or period character usually consider construction and sidewall style together instead of treating them as separate decisions. Even with the same 13-inch rim diameter, a bias-ply setup and a radial setup can create very different impressions.

Yes, modifications can affect tire fitment on a 1970 Opel even when the nominal size stays within the correct 13-inch range. Aftermarket wheels, suspension changes, ride-height adjustments, or bodywork differences can alter the space available for either a 560-13 bias-ply or a 165R13 radial.

That is why a modified car should be checked as it sits, not judged only by original specifications. Wheel width is especially important here because the available tire options do not all share the same rim-width range. Steering clearance and fender clearance should also be inspected before settling on a new set of tires.

Before road use, inspect the wheels for correct diameter and width, then confirm that each tire is mounted in the proper direction and seated correctly. The car should also be checked for suspension looseness, uneven ride height, and any contact risk at the fenders or during full steering travel.

A collector car also benefits from a basic condition review before the first longer outing. Tire pressure, lug hardware, signs of air loss, and any rubbing marks should be reviewed after the first short drive. That kind of recheck is especially helpful when the Opel has sat for long periods or has recently changed construction from bias-ply to radial.

Collector-car tires should be maintained with regular pressure checks, visual inspections, and clean storage conditions. On a 1970 Opel, that means watching for sidewall cracking, cuts, bulges, tread damage, or slow air loss whether the car runs 560-13 bias-ply tires or 165R13 radials.

Low-mileage vintage cars often age their tires long before they wear them out, so condition matters as much as tread depth. Keeping the car away from prolonged sunlight, excess heat, moisture, and ozone sources helps preserve the tires between drives. A short inspection before each outing is a smart habit, especially after long storage periods.