1973 MG Tire Fitment Guide

1973 MG vehicles use four sizes across two models. The MGB uses 165R14, 155R14, and 520-14, all on 14-inch rims, while the Midget uses 145R13 on a 13-inch rim. Rim-width guidance appears on some products: 165R14 runs from 4.0 to 6.0 inches depending on the tire, 155R14 appears at 4.00 to 5.50 inches, 520-14 appears at 3.50 to 4.00 inches, and 145R13 appears at 4.00 to 5.00 inches.

The practical takeaway is that year and make alone are not enough for a 1973 MG. You need to identify whether the car is an MGB or a Midget first, then match the wheel diameter and the exact size used on that model. If you have an MGB, the next step is deciding whether you want a radial tire or a bias-ply tire, because both paths exist within the same model year.

On a 1973 MG, 520-14 is a numeric bias-ply size. The 5.20 portion refers to the nominal section width in inches, and the 14 refers to the wheel diameter in inches. It is not a metric radial code, and it is not used across the full 1973 MG range; it applies to the MGB rather than the Midget.

That difference matters because a 520-14 points you toward a very different kind of tire than a 155R14 or 165R14. Numeric bias-ply sizing belongs to an earlier style of construction and appearance, so it usually appeals to owners chasing a more vintage look and feel. Before ordering, confirm that your MGB is actually running the correct 14-inch wheel and that the wheel width suits the tire you choose.

No. The 1973 MG MGB and 1973 MG Midget do not share a single common tire size. The MGB uses three 14-inch options—165R14, 155R14, and 520-14—while the Midget uses one 13-inch option, 145R13. That means the model determines both the tire code and the wheel diameter.

For a buyer, that makes model identification the first checkpoint, especially if the car has changed hands several times or has had wheels swapped over the years. A 14-inch MGB fitment and a 13-inch Midget fitment are not interchangeable. Checking the wheel, the existing sidewall marking, and the car's model identity together is the fastest way to avoid choosing the wrong size.

A 1973 MG MGB can go in two different directions: 520-14 as a bias-ply tire, or 155R14 and 165R14 as radial tires. The bias-ply option uses an older numeric format and is paired here with narrow whitewall styling, while the radial sizes use blackwall metric construction from brands such as Pirelli, Michelin, Firestone, and Vredestein. The choice is less about whether the tire fits the year and more about what kind of driving character and presentation you want from the car.

Owners aiming for a more vintage restoration feel often prefer the bias-ply route, while owners who expect regular road use often lean toward the radial path. The two radial sizes also keep the MGB in a sports-car-correct 14-inch format. Start by deciding whether authenticity of construction or more modern radial behavior matters more to your plans for the car, then verify the wheel width before settling on a specific tire.

1973 MG tires appear in two sidewall directions. The radial sizes—165R14, 155R14, and 145R13—are available as blackwalls, while the 520-14 bias-ply size for the MGB is available with narrow whitewall styling. That creates a clear visual split between the metric radial offerings and the numeric bias-ply offering.

For most British sports-car restorations of this era, blackwall radials tend to look the most natural if the goal is a clean, understated road-car presentation. A narrow whitewall on 520-14 pushes the car toward a more stylized period appearance and will stand out more visually than the radial options. If show authenticity matters, compare your intended event standards and period photos before choosing sidewall style strictly on looks.

1973 MG coverage includes several familiar names depending on size. The 165R14 is available from Pirelli, Michelin, and Vredestein; the 155R14 comes from Michelin and Firestone; the 520-14 comes from Premium Sport; and the 145R13 comes from Michelin and Firestone. Those brand choices are tied to the individual size rather than shared across every 1973 MG model.

That size-by-size brand spread is useful because it lets you narrow your search once you know your model and wheel diameter. An MGB owner has more brand overlap between the 14-inch radial sizes, while a Midget owner is focused on the 145R13 choices. If you are comparing tires within one size, it is worth looking at construction, sidewall style, load information, and speed rating rather than picking only by brand familiarity.

Rim-width guidance varies by size on 1973 MG vehicles. The 165R14 appears with fitment ranges of 4.0 to 5.5 inches on one tire and 4.50 to 6.00 inches on another. The 155R14 appears at 4.00 to 5.50 inches, the 520-14 appears at 3.50 to 4.00 inches, and the 145R13 appears at 4.00 to 5.00 inches. Those ranges are tied to the individual tire, not just to the nominal size code.

That means wheel width should be confirmed against the exact tire you plan to run, especially on an MGB where different sizes and constructions overlap on 14-inch wheels. A wheel that works for one 14-inch radial may not be ideal for a narrow numeric bias-ply, even though the rim diameter matches. Measuring the wheel or checking a known wheel specification before ordering helps avoid mounting issues and preserves the intended tire shape.

Inner-tube requirements vary by size and by product on 1973 MG tires. The 165R14 and 145R13 ranges include products with TL tubeless markings, and the 155R14 range includes one product with a TL marking while another does not. The 520-14 bias-ply options should be treated with extra care and checked against the specific tire and wheel combination before deciding on tube use.

The key point is not to assume every tire in the same nominal size uses the same setup. Wheel design, tire construction, and the sidewall marking all matter. Before finalizing the order, check the exact product marking and the condition and style of the wheel you plan to use. If the car still wears original-style wheels, tube compatibility is one of the most important setup details to confirm.

A 1973 MG MGB's 165R14, 155R14, and 520-14 sizes all share the same 14-inch rim diameter, so they can align at the wheel-diameter level. That does not automatically make every original wheel equally suitable for every one of those tires, because the available rim-width ranges differ between the metric radials and the 520-14 bias-ply size. The wheel must match both the diameter and the width needs of the exact tire.

For an owner comparing MGB tire options, that means the original wheel can be a starting point but not the final answer by itself. A radial and a narrow numeric bias-ply may both mount on 14-inch wheels while preferring different width windows. Check the actual wheel width before switching from one size family to another, particularly if the car has aftermarket wheels or a long restoration history.

A 1973 MG should be stored in a cool, dry, dark space with the tires kept away from direct sunlight, electric motors, welders, furnaces, and other ozone-producing equipment. Maintain proper inflation, keep the car off damp ground, and move it periodically so the same patch of tread is not carrying the load for months at a time. Bias-ply tires such as the MGB's 520-14 are more prone to temporary flat-spotting during long static storage than radial tires.

If the car will sit for an extended season, many owners either roll it occasionally or support it in a way that reduces continuous load on the tires. That is especially helpful for collector cars that are driven only in fair weather. Good storage habits protect both the tread and the sidewalls, and they help preserve the ride quality you expect when the car comes back out for spring or event-season use.

On a 1973 MG, tire age matters more than mileage in many cases because these cars are often driven sparingly. A sensible rule is to evaluate tires closely once they reach the five- to seven-year range and to treat about ten years as the point where replacement deserves serious consideration, even if the tread still looks usable. The DOT date code on the tire sidewall is the best starting point for determining age.

Collector-car tires can look healthy while the rubber compound has already aged beyond its best years. Storage conditions, heat cycles, inflation habits, and long periods of inactivity all influence service life. If a 1973 MG still rides on older tires from a previous restoration, age should be checked before any long drive, regardless of how many miles the car has covered since the tires were mounted.

Tires on a 1973 MG should be inspected before every drive and again before any longer outing. Look for sidewall cracking, tread separation, punctures, bulges, uneven wear, and pressure loss. On cars using tube-type setups or older wheel designs, pay extra attention to valve stems and any signs that the tire is not sealing or seating as it should.

Frequent checks matter because a lightly used vintage sports car can spend weeks parked and then be expected to run at road speed with little notice. A quick inspection takes only a few minutes and can catch age-related issues before they become a roadside problem. It is also a good opportunity to confirm that all four tires, plus the spare, still match the intended size and service condition for the car.

For a 1973 MG MGB, the era sits right in the period when bias-ply and radial thinking could overlap, but the sizes associated with the model here include both a traditional numeric bias-ply option, 520-14, and metric radial options, 155R14 and 165R14. That means construction choice is central to an authentic restoration plan. The correct answer for a particular car can depend on market, wheel equipment, and how closely the restoration is following original delivery form.

If you want the most exact period match, confirm the car's original market and equipment through factory literature, heritage records, or an MG marque specialist before committing. Avoid assuming that one MGB answer covers every car built in 1973. For many restorers, the right path is to decide first whether the project is being judged for originality or prepared for road use, then choose the size and construction that suit that goal.

Yes, correct tire fitment can matter quite a bit when showing a 1973 MG. Judges and knowledgeable enthusiasts often look at size, construction, sidewall appearance, and overall visual appropriateness for the car and its era. On an MGB, a bias-ply 520-14 with narrow whitewall presents very differently from a blackwall 155R14 or 165R14 radial, and those differences can influence how authentic the car appears in a judged setting.

That does not mean every event uses the same standard. Some local shows reward overall presentation more than strict factory correctness, while concours-style events can be much more particular. Before selecting tires for a show-focused 1973 MG, review the event rules and consult MG clubs or marque experts familiar with the model. Tire construction and sidewall style are often more visible to judges than owners expect.

The 1973 MG Midget is associated here with a single tire size, 145R13, and that points clearly toward a small metric radial on a 13-inch wheel. Michelin and Firestone both cover that size in blackwall form, which fits the Midget's compact, lightweight sports-car character. As with many imported cars of the period, exact original-equipment details can vary by market and by how narrowly you are defining originality.

For a faithful restoration, the safest route is to use 145R13 as the starting size and then refine the choice through period brochures, marque references, or owners' club guidance. If your car has changed wheels over the years, inspect the current wheel diameter before assuming the existing setup is correct. A proper Midget tire should preserve the car's light-footed look rather than overwhelm it visually.

1973 MG tires can be suitable for highway driving when they are the correct size, in sound condition, and used within their stated capabilities. Among the radial sizes, H-rated products carry a 130 mph ceiling and the 155R14 Michelin option carries a T rating with a 118 mph ceiling. The 520-14 bias-ply options do not present the same kind of speed-letter information here, so they should be treated with the more cautious expectations that usually accompany vintage-style construction.

In real use, the tire is only one part of the equation on a 1973 MG. Steering condition, brakes, suspension wear, wheel condition, and alignment often matter as much as the sidewall code, especially on older sports cars that may have sat unused for long periods. Before regular highway use, make sure the whole car is mechanically ready, not just that the tires are fresh.

Inflation pressure on a 1973 MG should follow the vehicle manufacturer's recommendation for the car and the tire maker's guidance for the exact product. Some tires here include load-and-pressure figures: the 165R14 Vredestein shows 1,102 pounds at 51 psi, the 155R14 Firestone shows 990 at 44 psi, the 520-14 Premium Sport shows 1230 at 60 psi, and the 145R13 Firestone shows 825 at 44 psi. Those figures are tire ratings, not automatic running pressures for every application.

That distinction is important because a reproduction or classic tire's maximum-rated pressure is not the same thing as the best operating pressure for your specific MG. Use the original handbook or marque guidance as the baseline, then confirm the exact product's sidewall and manufacturer recommendations. Never transfer a pressure from one size to another just because both happen to fit a 1973 MG model.

Before a longer drive in a 1973 MG, inspect all four tires and the spare for cracking, cuts, bulges, uneven wear, and stable inflation. Confirm that the tire size matches the model, especially if the car is an MGB with multiple possible fitments. If the setup uses tube-type components or older wheels, inspect valve stems and look for any signs of leakage or seating problems before the trip begins.

A proper pre-drive routine should also extend beyond the tires because a 1973 MG is old enough that several small issues can add up on the road. Check wheel fasteners, fluid levels, cooling condition, brake response, and the basic health of the electrical system. Tires are the first line of road contact, but on a vintage sports car they work best when the rest of the car is equally ready for distance.