1955 MG Tire Fitment Guide

1955 MG vehicles use three tire sizes across four model lines: 155R15, 560-15, and 550-15. The 155R15 radial fits the MG, MGA, Magnette, and Midget. The 560-15 bias-ply size fits the MG and MGA, while the 550-15 bias-ply size fits the Magnette and Midget. All three sizes use a 15-inch rim diameter, and listed rim-width ranges include 4.00 to 5.50 inches for 155R15, 4.5 to 5.50 inches for 560-15 depending on product, and 3.00 to 3.50 inches for 550-15.

That means year and make alone are not enough if you want the bias-ply size that matches your model family. Sports-car applications and sedan-based applications split into different numeric sizes even though they share wheel diameter. If your goal is simply a 15-inch radial fitment used across the whole 1955 MG range, 155R15 is the common option, but wheel width and the exact tire's sidewall and tube configuration still deserve a final check before you settle on a product.

On a 1955 MG, 560-15 is a numeric bias-ply tire size. The 560 portion is the nominal section-width designation used in period numeric sizing, and the 15 indicates the wheel diameter in inches. It is not a metric radial code, and it does not describe the tire the same way a modern P-metric or Euro-metric size would. Within the 1955 MG range, 560-15 applies to the MG and MGA models rather than the full lineup.

That matters because a buyer who sees only the shared 15-inch wheel diameter could assume all 1955 MG models use the same numeric bias-ply size, and they do not. The practical takeaway is to treat 560-15 as the sports-car branch bias-ply fitment in this year-and-make group. If you are restoring an MG or MGA and want a traditional mid-1950s construction and appearance, this is the numeric code to look for before comparing sidewall style and brand.

No. Every 1955 MG model listed here can use 155R15 radial tires, but the bias-ply sizes split by model. The MG and MGA use 560-15 bias-ply tires, while the Magnette and Midget use 550-15 bias-ply tires. All of them are 15-inch fitments, but the size code still changes with the model family, so there is more to confirm than rim diameter alone.

That is why model identification comes before product selection on a 1955 MG page like this one. If your car is already wearing radial tires, 155R15 may be the easiest path because it spans the entire range. If you are working toward an era-correct bias-ply setup, the exact model becomes critical, since choosing between 560-15 and 550-15 depends on whether your car is from the MG/MGA side or the Magnette/Midget side of the 1955 lineup.

For a 1955 MG, the choice between 155R15 and the model-specific bias-ply size usually comes down to how you want the car to feel and present. The 155R15 is a radial used across the full model range, while the bias-ply option is 560-15 for MG and MGA models or 550-15 for Magnette and Midget models. Radials generally appeal to owners who drive their cars more regularly, while bias-ply tires are the traditional construction associated with the mid-1950s period.

A restoration-minded owner often starts with the proper bias-ply size for the model because construction, profile, and sidewall character are part of the car's visual authenticity. A driver who wants one 15-inch radial fitment recognized across all four models often leans toward 155R15 instead. Either route can be appropriate, but your model determines which numeric bias-ply size belongs on the car, so identify that first before deciding how original or road-oriented you want the final setup to be.

1955 MG tire choices include both blackwall and whitewall presentations, but they are tied to specific sizes. The 155R15 radial options are blackwall tires. The 560-15 bias-ply size for MG and MGA applications is available in narrow whitewall and wide whitewall styles, while the 550-15 bias-ply option for Magnette and Midget applications is offered here as a blackwall. That gives the 1955 MG range a broader visual spread than many year-make pages with only one construction style.

For period appearance, blackwalls are usually the safer starting point on sporting British applications, while whitewalls are a styling choice some owners may want for a particular look or regional-market presentation. The main point is that sidewall style is not interchangeable across every size on this page. If appearance matters as much as fitment, choose your model first, then your size, and only then compare whether the available blackwall, narrow whitewall, or wide whitewall options suit the car you are building.

Several brands cover 1955 MG applications, depending on the size you need. In 155R15, the available brands are Firestone and Michelin. In 560-15, the available brands are Firestone and US Royal. In 550-15, the listed brand is Excelsior. Those brand choices also line up with different construction and styling directions, since the radial offerings are all in 155R15 while the numeric bias-ply sizes cover the more period-style fitments.

That brand spread gives 1955 MG owners a useful way to narrow the field once size is settled. If you have a car that can use 155R15, your comparison is among radial options from Firestone and Michelin, including differences in speed rating and tube designation on some Michelin products. If you need 560-15, your decision is more about whitewall style and brand preference. If you need 550-15, the path is simpler because the available fitment is concentrated in one brand and one sidewall style.

Rim-width requirements for 1955 MG tires vary by size. The 155R15 radial products list rim-width compatibility from 4.00 to 5.50 inches on the products that specify it. The 560-15 bias-ply products list either a 4.5-inch rim or a 4.50 to 5.50 inch range, depending on brand. The 550-15 bias-ply product lists a 3.00 to 3.50 inch rim-width range. All of the listed fitments are for 15-inch wheels, but width is where the differences become important.

That spread is why a 15-inch wheel alone does not answer the whole fitment question on a 1955 MG. A car converted from one setup to another over the years may still have wheels that suit one size better than another. Before choosing a tire, check the actual wheel on the car and compare its width against the specific product's approved range. That step is especially useful when moving between a shared radial fitment and a narrower model-specific bias-ply size.

Inner-tube requirements on 1955 MG tires depend on the exact product. In 155R15, tube status varies by product: one Michelin X radial is marked TL, one Michelin XAS is marked TT, and one Michelin XAS-FF is marked TL. The Firestone 155R15 listing does not include a TT or TL marker in the size string. The numeric bias-ply products shown in 560-15 and 550-15 do not carry tube-status markers in the size text here.

Because tube designation is not uniform even within 155R15, it is worth checking the individual tire's sidewall marking and matching that to the wheel type on your 1955 MG before installation. Wire-wheel and steel-wheel setups can have different practical considerations, and older collector cars often have a mix of reproduction and original components. Treat tube use as a product-by-product and wheel-by-wheel decision rather than assuming every 15-inch MG tire in this year is built the same way.

The listed 1955 MG tire sizes all use a 15-inch rim diameter, so wheel diameter itself is consistent across the range. That means an original 15-inch wheel is in the right diameter family for 155R15, 560-15, and 550-15. The important difference is rim width, because the listed compatible widths vary noticeably by size, from 3.00 to 3.50 inches for 550-15 up to 4.00 to 5.50 inches for 155R15 and 4.50 to 5.50 inches for some 560-15 products.

In practice, a 1955 MG owner should confirm the actual wheel width before assuming every listed size can be used on every original wheel. That is especially relevant on cars that may have changed hands, wheels, or suspension setups over decades of use. The diameter match opens the door, but width determines whether a specific tire is actually appropriate. If you are comparing the shared radial against a model-specific bias-ply size, wheel measurement is one of the smartest checks you can make first.

A 1955 MG should be stored in a cool, dry space away from direct sunlight, electric motors, battery chargers, welders, or other ozone-producing equipment that can age rubber faster. Keep the tires clean, maintain proper inflation during storage, and move the car periodically if it sits for long stretches. Bias-ply tires like 560-15 and 550-15 are more prone to developing temporary flat-spotting from extended static parking, while radial 155R15 tires generally tolerate storage a bit differently.

Long-term storage habits affect how the car feels the next time it goes out, especially on a light British car where tire behavior is easy to notice at low speed. If the car will sit for months, some owners use stands or reposition the vehicle occasionally to reduce stress on one contact patch. Whatever size your 1955 MG uses, protecting the tires from sunlight, ozone, and moisture will do more for longevity than simply covering the car and forgetting about it.

On a 1955 MG, tire age usually matters more than mileage because many collector cars are driven sparingly. A sensible rule is to evaluate tires closely once they reach about five to seven years of age and to consider replacement at around ten years regardless of tread depth. The DOT date code, sidewall condition, and any signs of cracking, hardening, or separation are more meaningful than odometer miles on a low-use MG.

That timeline applies whether your 1955 MG is on 155R15 radials or one of the bias-ply numeric sizes. A car that spends most of its life indoors can still age its tires out before it wears them out. If you recently acquired the car and the tire age is unclear, reading the date code and inspecting each tire carefully is a smart first step before planning any real road use, even if the tread still looks attractive.

Tires on a 1955 MG should be inspected before every drive and again before any longer outing or tour. Look for sidewall cracking, tread wear, cuts, bulges, and signs that the tire has been run underinflated. Check pressure regularly and make sure the car is not losing air between drives. If your chosen product uses an inner tube, valve stems and tube-related slow leaks deserve extra attention because they can affect confidence just as much as visible tread condition.

Frequent inspection is especially worthwhile on a vintage MG because the cars are light, communicative, and often driven seasonally rather than daily. Small problems can go unnoticed during storage and then show up quickly once the car is back on the road. Include the spare in the same routine, since an aged or damaged spare is of limited use on a tour. A few minutes of checking before departure is easier than diagnosing handling surprises after the drive begins.

A 1955 MG MGA would have been associated with bias-ply construction in period, not modern radial fitments as standard original-equipment practice. Within the 1955 MG range shown here, the MGA uses either 560-15 bias-ply tires or 155R15 radials as a later-style alternative fitment. The size most aligned with period construction is 560-15. Original-equipment brand choice could vary by market and history, so size, construction, and sidewall style are the safer authenticity anchors than assuming one universal brand.

For a restoration, that means the first authenticity decision is construction type, with bias-ply usually being the place to start for a 1955 MGA. After that, compare sidewall presentation and confirm whether your car's restoration goal is factory-stock, dealer-period, or simply era-appropriate. If the car is destined for judged events, marque clubs and model-specific registries are the right places to verify market- and trim-specific expectations, especially if prior owners changed wheels or switched the car to radial tires decades ago.

Correct tire fitment can matter quite a bit when showing a 1955 MG, particularly in classes that reward factory-style presentation. Judges and knowledgeable enthusiasts often notice whether the size, construction type, and sidewall treatment suit the car's era and model. On a 1955 MG, that can mean the difference between using a period-style numeric bias-ply size like 560-15 or 550-15 and using the shared 155R15 radial, which is more of a later-style driving choice than an originality choice.

The practical implication is that tires influence both stance and authenticity, not just ride quality. A car prepared for concours or marque judging should be compared against the event's own standards, since some shows are stricter than others about radial-versus-bias construction and whitewall usage. If your goal is a road-driven car with tasteful vintage appearance, you may have more freedom. If your goal is competitive originality, confirm the accepted size and sidewall style before finalizing the tire selection.

For a 1955 MG using 560-15 tires, both Firestone and US Royal offer bias-ply fitments with the same listed maximum load of 970 pounds at 32 psi. Both brands also offer narrow whitewall and wide whitewall versions in this size. The main specification differences shown here are in stated rim-width compatibility and weight: Firestone is listed for a 4.5-inch rim and weighs 18 pounds, while US Royal is listed for a 4.50 to 5.50 inch rim range and weighs 17 pounds.

That makes the comparison less about one being universally superior and more about matching the tire to your wheel and desired appearance. If your 1955 MG restoration calls for a specific whitewall width, either brand may cover it, but the approved rim-width range could steer the final decision. Checking your wheel first is especially worthwhile on a long-restored or modified car, since a one-size-fits-all assumption is less useful than choosing the 560-15 product that best aligns with the wheel already on the vehicle.

1955 MG tires can be suitable for highway use when the tire is in good condition, correctly fitted, and operated within its rated capability. The clearest speed-rated examples here are in 155R15 radial form, including T-rated products with a 118 mph ceiling and H-rated products with a 130 mph ceiling. The bias-ply 560-15 and 550-15 listings do not show speed-letter markings here, so they should be treated with the more conservative expectations typical of vintage-style construction.

For most normal collector-car highway use, the condition of the car itself often becomes the limiting factor before a quality tire does. A 1955 MG's brakes, steering, suspension, alignment, and overall maintenance have a major influence on how relaxed the car feels at speed. If you plan regular higher-speed touring, many owners favor the shared 155R15 radial route, while bias-ply owners should be realistic about the more traditional feel and keep the rest of the chassis in equally sound condition.

Inflation pressure on a 1955 MG should be matched to the specific tire size, product, and the vehicle manufacturer's recommendations rather than copied from another MG model or another tire type. Among the listed products, 155R15 includes a Firestone radial rated at 1045 pounds at 44 psi, while 560-15 bias-ply products are rated at 970 pounds at 32 psi. Those are tire ratings, not blanket instructions for every 1955 MG application, and 550-15 should not inherit pressures from the other sizes.

The smart approach is to start with the original owner's manual or factory guidance for your exact 1955 MG model and then compare that with the tire maker's published limits for the tire you choose. Reproduction and modern-construction tires do not always mirror period inflation practice exactly. What matters is using a pressure that supports the car correctly without assuming that one 15-inch MG tire can be inflated the same as another simply because the wheel diameter matches.

Before a longer drive in a 1955 MG, inspect each tire for cracking, cuts, bulges, abnormal wear, and signs of age-related hardening. Verify inflation pressures, check that the tires are holding air, and inspect valve stems carefully. If your chosen tire setup uses inner tubes, pay extra attention to stem condition and any slow leaks. The spare should also be checked, because a spare that is old, flat, or structurally suspect adds little reassurance on a tour.

Tires are only one part of pre-trip preparation on a car from this era, so pair that inspection with a broader look at brakes, steering, fluids, cooling, and wheel hardware. A well-sorted 1955 MG is a rewarding road car, but small issues become larger ones once miles build up away from home. Taking a few minutes to inspect the tires thoroughly before departure helps you catch age and setup problems early, whether the car is on shared-fitment radials or model-specific bias-ply tires.