1951 MG Tire Fitment Guide

1951 MG vehicles use three sizes: 155R15, 560-15, and 550-15. The 155R15 radial fits the 1951 MG MG, 1951 MG MGA, and 1951 MG Midget. The 560-15 bias-ply size fits the 1951 MG MG and 1951 MG MGA, while the 550-15 bias-ply size is specific to the 1951 MG Midget. All three sizes mount on 15-inch rims, but the recommended rim-width range changes by size, with 155R15 commonly listed for 4.00 to 5.50-inch rims, 560-15 for 4.5 to 5.50-inch applications depending on product, and 550-15 for 3.00 to 3.50-inch rims.

That means year and make alone are not quite enough for a bias-ply purchase on 1951 MG vehicles. A radial shopper has one shared size across the range, but a buyer pursuing a more era-correct bias-ply fitment needs to identify whether the car is an MG, an MGA, or a Midget before moving forward. Wheel diameter is shared, yet wheel width still needs to match the tire size you choose.

On a 1951 MG tire, 560-15 is a numeric bias-ply size. The 5.60 figure is the nominal section width expressed in the older inch-based style, and the 15 is the rim diameter in inches. It is not a radial code, and it does not use a modern metric format. Within the 1951 MG range, 560-15 applies to the MG and MGA model lines rather than the Midget.

A buyer looking at 560-15 should think of it as a traditional postwar fitment style that emphasizes period appearance and original-type construction. On 1951 MG vehicles, that usually matters most to restorers and show-minded owners, especially when choosing between blackwall and whitewall visual treatments elsewhere in the range. Before choosing one, make sure the car is one of the models that actually uses 560-15 and that the wheel width matches the product’s listed range.

No, not all 1951 MG models use the same tire size. All three listed models share 155R15 as a radial option, but the bias-ply fitments split by model: the 1951 MG MG and 1951 MG MGA use 560-15, while the 1951 MG Midget uses 550-15. The rim diameter remains 15 inches across the range, yet the width requirements are not the same from one size to another.

That distinction matters most when the goal is originality. If you are selecting a radial tire for regular road use, 155R15 gives you a common cross-model size to work from. If you are restoring the car around its original construction style, the exact model becomes the deciding factor, because the Midget’s narrower bias-ply sizing places it in a different fitment path than the MG and MGA.

For 1951 MG vehicles that accept both sizes, the choice usually comes down to construction type rather than rim diameter, because both are 15-inch tires. The 155R15 is a radial size offered in blackwall form by Firestone and Michelin, while 560-15 is a bias-ply size offered by Firestone and US Royal with narrow and wide whitewall styles. The radial route is the shared all-model option, but 560-15 applies only to the 1951 MG MG and 1951 MG MGA.

Owners who prioritize an earlier visual character and original-type construction usually gravitate toward the bias-ply choice on the models that use it. Owners who expect more regular road driving often prefer staying with the radial size because it keeps the car in a 15-inch format while using a more modern casing style. The right answer starts with the model, then the intended use of the car.

1951 MG tire sidewall styles vary by size. The 155R15 radial choices are offered as blackwalls, the 550-15 bias-ply option is also a blackwall, and the 560-15 bias-ply size adds both narrow whitewall and wide whitewall options. That makes 560-15 the only size in the 1951 MG range with visible whitewall variety, while the radial and the Midget-specific bias-ply size stay visually more restrained.

For a buyer, sidewall style is as much a restoration decision as a fitment decision. A blackwall typically suits a more understated sporting look, especially on small British cars, while a whitewall can shift the presentation toward a more stylized period appearance. If authenticity matters for a show car, choose the sidewall treatment only after checking the car’s market history, photos, and club guidance for how your particular 1951 MG is being judged or presented.

Four brands appear across the 1951 MG range: Firestone, Michelin, US Royal, and Excelsior. Firestone and Michelin cover the 155R15 radial size, Firestone and US Royal cover the 560-15 bias-ply size, and Excelsior covers the 550-15 bias-ply size used on the Midget. Brand selection is therefore tied closely to the size and construction you need, not just to the year and make alone.

That brand spread gives 1951 MG owners a few different directions depending on how the car will be presented and driven. A radial shopper in 155R15 can compare Firestone and Michelin offerings within the same size, while a bias-ply shopper in 560-15 is comparing Firestone and US Royal largely through appearance details such as whitewall width. Midget owners using 550-15 have a narrower path and should verify wheel width first.

Rim-width requirements for 1951 MG tires depend on the size. The 155R15 radial is commonly listed for 4.00 to 5.50-inch rims. The 560-15 bias-ply size appears on products listed for 4.5-inch rims and for 4.50 to 5.50-inch rims, depending on brand. The 550-15 bias-ply option used on the 1951 MG Midget is listed for 3.00 to 3.50-inch rims.

That makes wheel width one of the most important checks before ordering a tire for any 1951 MG. Shared 15-inch diameter does not mean every tire can be mounted on every original wheel across the range. If the car has replacement wheels, widened steel wheels, or a mixed set from an earlier restoration, measure the wheel and compare it to the specific tire’s approved range instead of relying on the year alone.

Inner-tube requirements on 1951 MG tires vary by product in the 155R15 radial size. Michelin offers that size in both tube-type and tubeless forms, while another Michelin radial and the Firestone radial are listed without a mixed tube note in the size code. The 560-15 and 550-15 bias-ply products shown do not carry TL or TT markers in the size field, so the most important check is the sidewall marking on the exact product you choose.

For a buyer, that means tube fitment should be confirmed at the product level rather than assumed from the size alone, especially in 155R15. Tube use also depends on the wheel itself, including whether it is a tube-type design or has sealing issues that make tubeless service inappropriate. When setting up a 1951 MG, treat tube choice as part of the wheel-and-tire system, not as a generic rule for the whole year.

Original 1951 MG wheels can often be used with more than one listed tire size because all three sizes in this range share a 15-inch rim diameter. That means wheel diameter compatibility is straightforward between 155R15, 560-15, and 550-15. The limiting factor is width: 155R15 is suited to 4.00 to 5.50-inch rims, 560-15 generally needs 4.5 inches or more, and 550-15 is intended for much narrower 3.00 to 3.50-inch rims.

In practical terms, the same 15-inch wheel diameter does not automatically make every original wheel interchangeable across all 1951 MG models and sizes. A Midget wheel sized for 550-15 should not be assumed suitable for 560-15, and a wheel that accepts 560-15 may not reflect the intended setup for a Midget. Confirm the actual wheel width before changing size, even when the diameter appears to match.

A 1951 MG should be stored in a cool, dry space away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment that can age rubber prematurely. Keep the tires clean, maintain proper inflation during storage, and move the car periodically if possible. Bias-ply tires are generally more prone to temporary flat-spotting during long static storage than radials, so that matters on 560-15 and 550-15 fitments.

Collectors who leave a 1951 MG parked for long stretches often use tire cradles or place the car on stands to reduce sustained loading, especially with bias-ply constructions. Radials also benefit from careful storage, but they typically recover from short idle periods differently than older-style casings. Good storage habits preserve appearance as well as function, which matters on a classic sports car where sidewall condition is highly visible.

Tire life on a 1951 MG is usually determined more by age, storage conditions, and maintenance than by mileage. A collector car may cover very few miles while the rubber still ages out. As a general rule, tires should be evaluated carefully once they reach the 5- to 7-year range, and many owners begin serious replacement consideration by about 10 years regardless of tread depth. The DOT date code is the starting point for that conversation.

That age-based approach is especially important on low-use classics because old tires can look acceptable while the casing and rubber compounds have hardened or begun to crack. If a 1951 MG is driven only occasionally, it is easy to overestimate tire life by looking at remaining tread alone. The safer habit is to track age, inspect regularly, and replace on condition and calendar time rather than waiting for mileage to force the decision.

Tires on a 1951 MG should be inspected before every drive and again before any longer outing. Check inflation, sidewall cracking, tread wear, cuts, bulges, and any sign that the tire is not holding pressure consistently. On cars using tube-type products or tube-based wheel setups, valve stems and tube-related leakage deserve extra attention because slow pressure loss can be less obvious on a collector car that sits between drives.

Regular inspections matter because small, lightly driven classics often spend more time aging in storage than accumulating road miles. A quick walkaround before each drive can catch a developing issue long before it becomes a roadside problem. For a 1951 MG that will be driven any distance, inspect the spare as well, since an aged or underinflated spare is of limited value when the main set is already carrying the risks of an older vehicle.

A 1951 MG MG would originally have been associated with bias-ply construction rather than a later radial replacement, because bias-ply tires were the normal fitment style for early-1950s sports cars. Within the sizes available here, 560-15 is the model-specific bias-ply fitment for the 1951 MG MG, while 155R15 represents a radial option that preserves the 15-inch rim diameter but reflects a later construction type. No original-equipment brand should be assumed from the current replacement choices alone.

For a restoration, that means size, construction, and sidewall appearance all matter more than simply finding any tire that mounts. Owners aiming for strict originality usually start with the bias-ply path and then refine the sidewall treatment to suit the car’s presentation. If the goal is concours-level accuracy, check factory literature, period photos, and MG club guidance for market-specific details before treating any one replacement tire as the final answer.

Correct tire fitment does matter when showing a 1951 MG, especially in judged settings where overall authenticity is part of the evaluation. Judges and knowledgeable enthusiasts often notice whether the car is wearing the proper size family, whether the construction is bias-ply or radial, and whether the sidewall style suits the period presentation. A modern radial on a car judged for strict originality can stand out just as quickly as an incorrect whitewall treatment.

That does not mean every show car must use the same setup, because event standards vary widely between casual displays, marque events, and formal concours. Some owners accept a radial compromise for touring while others keep a separate set of more authentic tires for judged appearances. For a 1951 MG, the smartest approach is to match the tire choice to the level of authenticity expected by the event rather than assuming one setup fits every purpose.

For the 1951 MG in 560-15, Firestone and US Royal both offer bias-ply tires with the same listed maximum load figure of 970 pounds at 32 psi, but they differ in sidewall presentation and approved rim-width listings. Firestone’s 560-15 products are listed on 4.5-inch rims and are offered in 1.00-inch narrow whitewall and 2.75-inch wide whitewall versions. US Royal lists 560-15 for 4.50 to 5.50-inch rims and offers 1.00-inch narrow whitewall and 2.25-inch wide whitewall versions.

That means the real comparison is not raw load capacity but wheel compatibility and visual effect. If the car’s wheel width sits near the wider end of the range, the US Royal listing may be especially relevant, while Firestone may appeal to buyers who prefer its specific whitewall proportions. On a 1951 MG show car, the difference between a 2.25-inch and 2.75-inch whitewall can noticeably change the stance and period flavor.

1951 MG tires can be suitable for highway driving when they are in good condition, properly inflated, correctly fitted to the wheel, and used within the capability of the specific product. In 155R15, available speed ratings include T, which is rated to 118 mph, and H, which is rated to 130 mph. The bias-ply sizes shown do not list modern speed letters in the same way, so they should be approached with the expectations appropriate to traditional collector-car tire construction.

On a 1951 MG, the broader road-safety picture usually extends beyond the tire itself. Brakes, suspension condition, steering play, and the car’s overall mechanical state are often more limiting than the radial tire’s rated ceiling during normal highway use. For touring, choose a tire that matches how the car will be driven and keep speed, weather, and braking distances in line with what an early-1950s MG can realistically handle.

Inflation pressure on 1951 MG tires should be set with the car’s factory guidance in mind first, then checked against the tire maker’s rated limits for the exact product. Within the available sizes here, 155R15 includes a listed maximum load figure of 1045 pounds at 44 psi on one product, while 560-15 products show 970 pounds at 32 psi. Those numbers are rated maximum load-and-pressure figures for those specific tires, not a universal operating pressure that should be transferred to every 1951 MG size.

The practical approach is to use the owner’s manual or marque guidance for baseline cold inflation and then confirm that the chosen tire’s sidewall and specifications support that use. Do not apply a 560-15 pressure to a 155R15 radial, or vice versa, simply because both fit 15-inch rims. Construction type, load capacity, and wheel width all influence how the tire should be set up on the car.

Before taking a 1951 MG on a longer drive, inspect all four tires for cracking, cuts, bulges, uneven wear, and correct cold inflation. Check that each wheel is secure, verify valve-stem condition, and inspect the spare so it is actually usable if needed. If the car uses a tube-type setup, pay extra attention to pressure retention and valve hardware because a slow leak can go unnoticed when the car is driven infrequently.

Tires are only one part of the pre-drive routine on an early-1950s sports car, so include brakes, wheel bearings, steering response, lights, and fluid levels in the same inspection. A 1951 MG rewards preparation because small issues become more noticeable at sustained road speeds than they do on short local drives. Taking a few extra minutes in the garage is often what turns a long outing into an enjoyable one rather than a troubleshooting stop.