1957 Morgan 4-4 Series & Plus 4 Tires

The 1957 Morgan 4-4 Series & Plus 4 uses either a 560-15 bias-ply tire or a 155R15 radial tire. Both are associated with 15-inch wheels, so the fitment question is less about wheel diameter and more about which construction and size format the car is set up to use.

That distinction matters because a narrow bias-ply Morgan and a radial-equipped Morgan can present very differently in both appearance and road feel. Start by confirming what is currently on the car, then compare wheel width, tire construction, and overall clearance before selecting between the traditional 560-15 path and the 155R15 radial path.

The tire sizes associated with the 1957 Morgan 4-4 Series & Plus 4 both use a 15-inch rim diameter. That applies to the 560-15 bias-ply fitment and the 155R15 radial fitment, so wheel diameter remains consistent even though the tire sizing systems are different.

Rim diameter is only part of the fitment picture on a car this narrow and traditional. It is still important to check actual wheel width before choosing a tire, especially when moving between bias-ply and radial construction, because the tire may share the same 15-inch diameter while needing a different wheel-width range or presenting differently on the car.

The 1957 Morgan 4-4 Series & Plus 4 Base is associated with both of the main tire sizes for this model core: 560-15 in bias-ply construction and 155R15 in radial construction. Rather than a unique trim-only fitment, the Base follows the same two established size paths.

That makes the selection process more about the car's actual wheel and tire setup than about trim differences. A Morgan that has stayed close to a traditional restoration may still be on 560-15 bias-ply tires, while another may already be using 155R15 radials, so checking the car itself remains the most practical first step.

On the 1957 Morgan 4-4 Series & Plus 4, 560-15 is a bias-ply tire size. It uses the vintage numeric sizing system, and the available 560-15 products for this application are bias-ply tires rather than standard modern radials.

That matters because a bias-ply tire affects both the car's appearance and the way it feels on the road. Owners keeping a more traditional setup often stay with 560-15, while those considering radial construction should compare the available radial equivalents carefully and confirm wheel width, tire dimensions, and chassis clearance before making a change.

Two radial-equivalent sizes are available for 560-15. The first is 155R15, which is the 80-series metric radial equivalent, and the second is 560R15, which is a bias-look radial equivalent intended to retain a more traditional visual presentation.

Those options serve slightly different goals even though both fall into the radial category. The recommended rim-width range for the equivalent path is 4 to 5 inches, and the right choice still depends on the car's wheel width, overall tire dimensions, and available clearance at the fenders and steering range.

Start by confirming the wheel diameter and actual wheel width, then compare the intended radial size with the Morgan's present tire and wheel setup. For a car using 560-15 bias-ply tires, 155R15 and 560R15 are the radial-equivalent paths worth evaluating rather than guessing from modern sizing charts.

A narrow British sports car leaves little room for casual substitution, so the conversion should also include checks for steering clearance, fender clearance, and suspension condition. The goal is to make sure the radial choice works with the car's hardware and intended use, not simply that it shares the same 15-inch rim diameter.

The main considerations with 560-15 are construction, sidewall appearance, and wheel compatibility. This size is offered in bias-ply form with blackwall, narrow whitewall, and wide whitewall presentations, and available series come from Firestone, US Royal, Coker Classic, and Pro-Trac.

Choosing among them depends on how the Morgan is used and how traditional the finished look needs to be. A restoration-oriented car may call for a more period-style bias-ply presentation, while a more specialized setup may lead you to compare rim-width specifications, load figures where stated, and whether the tire's visual style suits the car.

Sidewall style depends on the size and construction you choose. The 155R15 radial options are blackwall tires, while the 560-15 bias-ply range includes blackwall, narrow whitewall, and wide whitewall choices.

That gives the Morgan owner a clear appearance decision before even comparing brands. Blackwall generally keeps the presentation restrained and sporting, while whitewall treatments create a more decorative period-style look. Since sidewall style does not change the need for proper fitment, keep wheel width and intended construction in view while narrowing the visual choice.

The 1957 Morgan 4-4 Series & Plus 4 has tire choices from Firestone, Michelin, Avon, Vredestein, US Royal, Coker Classic, and Pro-Trac. Brand availability depends on the size path, with 155R15 carrying several radial lines and 560-15 covering several bias-ply lines.

Brand alone should not be the first filter on a car like this. It is better to start with the correct size and construction, then compare each brand's available tire series, sidewall presentation, and rim-width suitability. That approach keeps the choice tied to the Morgan's setup instead of treating all 15-inch tires as interchangeable.

A period-style 1957 Morgan 4-4 Series & Plus 4 usually starts with the 560-15 bias-ply size, because that sizing format and construction align more closely with the car's era and traditional visual proportions. Within that size, blackwall and whitewall versions create noticeably different presentations.

The best appearance choice depends on the way the individual car is being restored, not just on the year and model name. Owners pursuing exact historical accuracy should compare the tire choice with period photos, marque-club guidance, and restoration records, while owners focused on overall vintage character can choose the sidewall style that best suits the car.

Tire construction changes more than ride and handling on a restored 1957 Morgan 4-4 Series & Plus 4; it also changes the car's visual character. A 560-15 bias-ply tire gives a more traditional presentation, while a 155R15 radial introduces a later-style sizing format even though it remains narrow and appropriate in scale.

That difference becomes especially noticeable on a small, open British sports car where the tires are a visible part of the stance. A bias-look radial can be useful for owners who want radial construction without giving up as much vintage visual character, but wheel width and overall fitment still need to be checked carefully.

Yes, modifications can affect tire fitment on a 1957 Morgan 4-4 Series & Plus 4 even when the tire size appears correct on paper. Changes such as aftermarket wheels, different wheel widths, altered offset, suspension work, or body adjustments can all influence how a 560-15 or 155R15 tire sits and clears.

That is especially important on a narrow, lightweight sports car with limited extra space around the tires. Any modified Morgan should be checked at full steering lock and through normal suspension movement, and the actual wheel dimensions should be verified before choosing between the available bias-ply and radial size paths.

Before driving a 1957 Morgan 4-4 Series & Plus 4 on new tires, inspect wheel condition, confirm proper tire pressure, and make sure each tire is seated correctly and clears the body and suspension. It is also wise to look over steering components and suspension condition on a car that may have spent long periods parked.

A short initial road test is the right next step because it helps reveal rubbing, pull, vibration, or unusual response before the car is driven farther. Vintage sports cars can be sensitive to setup details, so checking lug security, air retention, and tire-to-body clearance again after the first miles is a smart precaution.

Tires on a collector 1957 Morgan 4-4 Series & Plus 4 should be inspected regularly for cracking, bulges, cuts, uneven wear, and slow air loss, even if the car is driven only occasionally. Collector cars often age their tires through time and storage conditions as much as through mileage.

Proper inflation, clean storage, and protection from prolonged sunlight, heat, and ozone sources all help preserve the tires between drives. The car should also be checked before longer trips, since a lightly used Morgan may seem road-ready while still carrying aged tires or a setup issue that only becomes noticeable at speed.