1959 Morgan Plus 4 Tires

The 1959 Morgan Plus 4 is associated with two tire sizes: 560-15 in bias-ply construction and 155R15 in radial construction. Both are 15-inch tire sizes, so the decision is not about wheel diameter as much as construction type and the setup currently on the car.

A car that still wears period-style wheels and is being restored around traditional appearance may stay with 560-15, while a car set up for radial use may point toward 155R15. Before choosing, confirm the wheel width and inspect for any past changes that could affect clearance or the way the tire sits on the rim.

The tire sizes associated with the 1959 Morgan Plus 4 both use a 15-inch rim diameter. That applies to the 560-15 bias-ply size and the 155R15 radial size, so the wheel diameter remains consistent even though the construction type changes.

Diameter is only the first check. Wheel width also matters, especially when comparing a bias-ply size with a radial alternative, because the available tires do not all share the same recommended rim-width range. Measuring the actual wheels on the car is worthwhile if the Morgan has been modified or if the wheel history is uncertain.

560-15 is a vintage numeric bias-ply size. The 560 refers to an approximate 5.60-inch nominal section width, and the 15 identifies the wheel diameter in inches. On a 1959 Morgan Plus 4, that size represents the traditional bias-ply fitment style tied to a period-looking tire.

Understanding that format helps separate an original-style size from a modern metric radial such as 155R15. The two sizes are related in purpose, but they are not described in the same way. Anyone replacing older tires should confirm the actual wheels and look at body and steering clearance before changing construction or tire profile.

560-15 is a bias-ply tire size for the 1959 Morgan Plus 4. It uses the older numeric sizing system and keeps the car in a traditional construction associated with many period sports cars using narrow 15-inch tires.

That matters because construction affects both appearance and the way the car is set up. A bias-ply choice keeps the original-style sizing format, while a move to radial construction shifts the conversation to radial equivalents and wheel compatibility. Owners considering a change should confirm wheel width and examine clearance at full steering lock.

The radial equivalents for 560-15 are 155R15 and 560R15. The 155R15 is the 80-series metric radial equivalent, while 560R15 is the bias-look radial equivalent that keeps a more traditional visual character than a standard metric radial size.

Those two alternatives serve different goals, even though both move away from a bias-ply construction. A recommended rim-width range of 4 to 5 inches applies to this equivalent path, and the final choice should still be checked against the car’s wheel dimensions, suspension condition, and available fender and steering clearance.

Start by confirming the existing wheel diameter and width, then compare the radial size you are considering against the tire currently on the car. For a 1959 Morgan Plus 4, that usually means evaluating 155R15 or 560R15 as radial alternatives to the 560-15 bias-ply size.

Construction changes should also be checked in context of the whole car. Look at steering travel, fender clearance, suspension condition, and any signs of aftermarket wheel or chassis changes. A radial equivalent can be a useful alternative, but it should be treated as a fitment decision that needs verification, not as an automatic swap.

The main considerations are keeping the correct 15-inch bias-ply size, matching the tire to the wheel width on the car, and deciding how much appearance matters. In 560-15, choices include blackwall, narrow whitewall, and wide whitewall versions across Firestone, US Royal, Coker Classic, and Pro-Trac offerings.

Beyond sidewall style, compare the intended character of the tire. Some 560-15 options are clearly restoration-oriented bias-ply designs, while another is a Street Pro Front Runner. It also helps to review load figures where given, such as 970@32 psi on several options, so the tire choice matches how the Morgan will actually be driven.

The sidewall choices depend on which size and construction you choose. In 560-15 bias-ply, blackwall, narrow whitewall, and wide whitewall options are available. In 155R15 radial form, the available tires are blackwall.

That makes sidewall style an important part of the decision, especially on a small British sports car where the tires are highly visible. A whitewall can create a very different period-style impression than a blackwall, but appearance should still be balanced against construction type, wheel fit, and how the car will be used on the road.

Brands available for the 1959 Morgan Plus 4 include Firestone, Michelin, Avon, Vredestein, US Royal, Coker Classic, and Pro-Trac. The mix changes by size, with 155R15 leaning toward radial touring and performance-oriented series, while 560-15 includes several traditional bias-ply and appearance-focused options.

Brand choice should come after the size and construction are settled. Once that is clear, compare the series, sidewall treatment, rim-width specification, and any available load information within the correct size. That approach keeps the decision centered on fitment and intended use instead of choosing by name alone.

For a period-style presentation, the 560-15 bias-ply size is the natural starting point because it keeps the car in a traditional numeric bias-ply format. Within that size, blackwall, narrow whitewall, and wide whitewall options create different visual results without changing the basic vintage construction style.

The final choice depends on how strictly the car is being restored and what visual character suits it best. A buyer focused on close historical appearance should compare period photos, marque-club guidance, or restoration records before choosing a sidewall treatment, since available styles should not be assumed to match every car exactly.

Construction affects both the look and the visual attitude of the car. A 560-15 bias-ply tire gives the 1959 Morgan Plus 4 a more traditional presentation, while a 155R15 radial introduces a more modern sizing format even though it stays on the same 15-inch wheel diameter.

That difference can matter as much as the tread or sidewall itself on a restoration-minded car. Buyers who want radial road manners without giving up a vintage impression may also consider the 560R15 bias-look radial equivalent, but it should still be checked carefully against wheel width and overall fit before making the change.

Yes. Even though the 1959 Morgan Plus 4 is associated with 15-inch tire sizes, changes to wheel width, wheel offset, suspension height, steering components, or body clearance can alter what works cleanly on the car. That applies whether the car is using 560-15 bias-ply tires or 155R15 radials.

A modified car should be measured rather than assumed to match stock fitment. Check clearance at full lock, look for rubbing marks inside the fenders, and confirm that the actual wheels match the tire’s rim-width requirements. Small sports cars can be especially sensitive to changes that seem minor on paper.

Begin with the basics: verify tire pressure, inspect the wheels for damage, and make sure the tires seat properly on the rims. Then look at clearance around the fenders, suspension, and steering components so the new tires have room throughout the full range of movement.

A short test drive should be followed by another inspection. Recheck pressure, look for any fresh rubbing, and pay attention to how the car tracks and steers. On a collector car that may sit for long periods, it is also smart to inspect older tubes, valve stems, and the condition of the spare before regular road use.

Collector-car tire care starts with regular pressure checks, visual inspection, and proper storage. Whether the 1959 Morgan Plus 4 is on 560-15 bias-ply tires or 155R15 radials, watch for sidewall cracking, cuts, bulges, uneven wear, and any signs that the tire is losing air between drives.

Storage conditions matter because many collector cars spend more time parked than driven. Keep the car away from prolonged sunlight, excess heat, and ozone-producing equipment, and move it periodically so the tires are not carrying the same load point for months at a time. Low annual mileage does not prevent age-related tire deterioration.