1973 Opel Tires

The 1973 Opel uses two primary tire sizes: 165R13 in radial construction and 560-13 in bias-ply construction. Both are 13-inch tire sizes, but they follow different sizing systems and can point to different wheel-width and appearance considerations.

The practical decision is not just picking a 13-inch tire, but matching the size to the car's actual setup. A car already running radial wheels may be better aligned with 165R13, while a traditional bias-ply presentation may lead toward 560-13. Wheel width, tire construction, and clearance around the fenders and suspension should all be confirmed before changing from one type to the other.

The primary tire fitments for a 1973 Opel both use a 13-inch rim diameter. That applies to the 165R13 radial size and the 560-13 bias-ply size, so the wheel diameter remains consistent even though the tire constructions differ.

Rim diameter is only part of the fitment picture. A 13-inch wheel still needs the right width for the intended tire, especially when comparing 165R13 radial products with 560-13 bias-ply products. Before choosing a tire, measure the wheel if the car has been changed from stock, and make sure the selected tire's width range matches the wheel rather than relying on diameter alone.

The 1973 Opel GT can use the same two primary tire sizes associated with this model: 165R13 in radial form and 560-13 in bias-ply form. That means GT fitment does not introduce a separate wheel diameter or a unique third size.

Even with shared fitment at the sub-model level, the tire choice still depends on the specific car. Some owners will want the blackwall radial look and road-oriented character of 165R13, while others may prefer the traditional bias-ply appearance available in 560-13. Looking at the wheels already on the car is the fastest way to avoid selecting the right diameter but the wrong overall tire type.

On the 1973 Opel, 560-13 is a bias-ply tire size. It uses the older numeric sizing system and appears in bias-ply products with vintage-style sidewall treatments such as narrow whitewall and wide whitewall options.

That matters because a bias-ply 560-13 should not be confused with a radial simply because it shares the same 13-inch rim diameter. Tire construction affects the look of the sidewall, the available wheel-width range, and the overall selection path. Anyone moving away from 560-13 should compare the wheel itself and the car's present clearance rather than assuming any 13-inch radial is automatically suitable.

Radial equivalents for 560-13 include 155R13 as an 80-series metric radial, P155/75R13 as a P-metric 75-series radial, and P155/70R13 as a P-metric 70-series radial. No bias-look radial equivalent is paired with 560-13 here.

Those three options give different sizing conventions and profile families, but they should be treated as alternatives to evaluate rather than automatic replacements. A recommended rim-width range of 4-5 inches applies to the equivalent path, so wheel width is especially important. Diameter, section width, and clearance at the front suspension and fenders are also worth checking before converting a 560-13-equipped Opel to a radial alternative.

Start by confirming which original size is on the car and whether the wheels are suitable for the radial alternative being considered. A 560-13 bias-ply Opel can be evaluated against 155R13, P155/75R13, or P155/70R13 radial equivalents, but the wheel width and tire dimensions still need to make sense together.

Construction changes can affect how the tire sits on the wheel and how much space it uses in the car. Look closely at steering clearance, fender room, suspension condition, and the wheel's actual width before making the switch. It also helps to inspect for previous modifications, because a lowered car or one with replacement wheels may need a different fitment approach than an Opel still using its original-style setup.

The first consideration is whether the car is set up for the 165R13 radial fitment or the 560-13 bias-ply fitment. After that, the choice becomes one of construction, wheel compatibility, and the visual character you want the tire to bring to the car.

A 165R13 selection leans toward blackwall radial offerings from Michelin and Dunlop, while 560-13 opens the door to traditional bias-ply choices from BFGoodrich and Firestone with whitewall styling. It also helps to compare rim-width specifications, load figures where available, and the way the car will be used. A restoration-oriented car and a regularly driven car may lead to different but still appropriate choices.

Sidewall choices for the 1973 Opel vary by tire size and construction. The 165R13 radial options are blackwall designs, while the 560-13 bias-ply options include narrow whitewall and wide whitewall styles.

That makes sidewall style an important part of choosing the overall presentation of the car. A blackwall radial keeps a restrained European look, while whitewall bias-ply tires create a more vintage visual statement. Sidewall appearance should still be chosen after the correct size and wheel compatibility are settled, since a preferred whitewall or blackwall treatment is only useful if it matches the car's actual tire format and wheel setup.

Michelin and Dunlop offer radial choices in 165R13 for the 1973 Opel, and BFGoodrich and Firestone offer bias-ply choices in 560-13. The available assortment spans both European-style radial products and traditional American-brand bias-ply designs.

Brand alone should not drive the decision. The more useful comparison is which brand appears in the correct size, construction, sidewall style, and tire series for the car you have. Michelin and Dunlop are relevant when the Opel is using the radial size, while BFGoodrich and Firestone become the focus for a bias-ply setup. Matching the tire to the intended look and wheel dimensions matters more than choosing by name alone.

A period-style 1973 Opel can go in two distinct directions depending on the look being preserved. The 560-13 bias-ply size supports a more traditional vintage presentation, while the 165R13 radial size keeps the car in a European-style radial format that also suits the era.

The better choice depends on how the particular Opel is being interpreted. Some restorations favor the visual character of a bias-ply sidewall, especially with whitewall treatments, while others are better served by the simpler blackwall radial appearance. When exact originality matters, compare the tire decision against marque-specific historical references and the car's existing wheels before settling on style alone.

Tire construction changes more than ride and road feel on a restored 1973 Opel; it also changes the visual stance of the car. A 560-13 bias-ply gives the Opel a distinctly vintage presentation, while a 165R13 radial creates a more modernized, European blackwall look within the same 13-inch diameter family.

That visual difference often shapes the whole restoration direction. Whitewall bias-ply options can make the car feel more formal or more deliberately vintage, while blackwall radials tend to look cleaner and more understated. Construction should be chosen with the wheel width and the car's intended use in mind, because appearance is only one part of getting the restored Opel set up properly.

Yes, modifications can change what works on a 1973 Opel even when the original tire sizes are known. Aftermarket wheels, altered wheel widths, suspension changes, or body modifications can all affect whether a 165R13 radial or 560-13 bias-ply setup remains practical on the car.

A 13-inch diameter match does not settle everything. The wheel's actual width, the tire's section profile, and available space at the fender and steering components all deserve attention once a car has been changed from original form. Measuring the wheels and inspecting clearance with the car at normal ride height is a smart step before choosing replacement tires for a modified Opel.

Before road use, inspect the wheels, valve stems, lug hardware, and the general condition of the suspension and steering components. It also makes sense to confirm that the new tires match the wheel diameter and width requirements for the 1973 Opel's chosen size.

Tires should be checked for proper inflation, even tread seating, and adequate clearance once mounted. A brief look at brake condition and wheel-bearing play is worthwhile on a collector-era car that may sit for long stretches. After the first miles, recheck pressure and look for any rubbing marks or unusual wear patterns that could point to alignment, clearance, or mounting issues.

Collector-car tires on a 1973 Opel should be maintained with regular pressure checks, periodic visual inspection, and attention to age-related deterioration as well as tread wear. That applies whether the car is running 165R13 radials or 560-13 bias-ply tires, since low annual mileage does not prevent rubber from aging.

Storage conditions play a big role in tire life. Keeping the Opel away from prolonged sunlight, excess heat, standing moisture, and ozone sources helps preserve the sidewalls and tread. Rotate the car's position occasionally during long storage, and inspect for cracking, bulges, cuts, or persistent air loss before each driving season. A tire that looks acceptable at a glance still deserves a close check before highway use.