The 1974 MG MGB sits at an interesting point in the long-running MGB story, balancing the familiar British sports-car character of the open Roadster with the more enclosed GT Coupe. Tire choice on this exact model depends on body style and construction, with 165R14 radial fitment for the GT Coupe and either 155R14 radial or 520-14 bias-ply fitment for the Roadster, all on 14-inch rims. That creates a meaningful decision between traditional bias-ply presentation and classic radial road use, along with differences in brand, tire series, and sidewall treatment. Getting the right tire starts with confirming the exact sub-model and deciding whether originality of look or modernized drivability matters more.
Which Tire Size Is Right for The 1974 MG MGB
Three primary tire sizes apply to the 1974 MG MGB, and the correct choice depends on the exact sub-model and construction type. All three sizes use a 14-inch rim, but the GT Coupe uses a different radial size than the Roadster, while the Roadster also has a bias-ply option. The first step is confirming whether the car is a GT Coupe or Roadster, then choosing the size and construction that match the car's current wheels and restoration goals.
165R14 is a Euro-metric radial size with a nominal section width of 165 millimeters, radial construction, and a 14-inch rim diameter. On the 1974 MG MGB, this size is used on the GT Coupe and suits buyers looking for a classic radial format rather than a bias-ply tire. Available choices include Pirelli, Michelin, and Vredestein in blackwall form across the Cinturato CA67, Michelin XAS, and Sprint Classic series. It is the size to evaluate when preserving the GT Coupe's intended radial fitment while comparing brand character, rim-width compatibility, and period-style appearance.
155R14 is a narrower Euro-metric radial size, using a 155-millimeter nominal section width and fitting a 14-inch wheel. On the 1974 MG MGB, this radial size applies to the Roadster and gives that sub-model a distinctly classic small-car radial fitment. Michelin and Firestone both offer blackwall versions, including the Michelin X Radial and Firestone F560 Radial series. This is the size to consider when the Roadster is set up for radial tires and the goal is to stay with the proper size format while comparing rim-width range, load specification, and tire-series character.
520-14 is a numeric bias-ply size in which the 5.20 designation refers to the tire's nominal section width class and the 14 identifies wheel diameter. On the 1974 MG MGB, this size applies to the Roadster and represents the bias-ply fitment choice rather than a radial construction. Available options center on Premium Sport bias-ply tires with narrow whitewall styling in the Premium Sport Lowrider series. This size makes sense for a Roadster owner focused on a more traditional visual presentation, but wheel width and overall vehicle setup should still be checked before selecting among the available versions.
Sub-model fitment matters on the 1974 MG MGB because the GT Coupe and Roadster do not share the same tire setup. Confirming the exact body style is the first step, since the GT uses one radial size while the Roadster can be fitted with either a radial or a bias-ply tire.
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1974 MG MGB GT Coupe
The 1974 MG MGB GT Coupe uses a 165R14 radial tire on a 14-inch rim. That keeps tire selection focused on choosing among classic blackwall radial offerings and comparing series and rim-width compatibility rather than sorting through multiple primary sizes.
The 1974 MG MGB Roadster uses either a 155R14 radial or a 520-14 bias-ply tire, both on 14-inch rims. That makes construction choice central, since the decision may involve keeping a traditional bias-ply look or matching a Roadster that is already set up for radial road use.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Best 1974 MG MGB Tires for Sale
Available 1974 MG MGB tire choices span Michelin, Pirelli, Vredestein, Firestone, and Premium Sport, with differences by size, construction, and series. Radial options are blackwall tires in several classic series, while 520-14 bias-ply selections focus on narrow whitewall styling.
Common 1974 MG MGB tire questions usually come down to body-style fitment, 14-inch rim compatibility, radial versus bias-ply construction, and how to choose among blackwall or whitewall options for road use and restoration goals.
Tire Size & Fitment
What tire size fits a 1974 MG MGB?
A 1974 MG MGB can use 165R14, 155R14, or 520-14, depending on the sub-model and construction. The GT Coupe uses 165R14 radial tires, while the Roadster uses either 155R14 radial tires or 520-14 bias-ply tires. All three fitments use a 14-inch rim.
The practical question is not just size, but which version of the MGB is being fitted and whether the car is staying with radial or bias-ply construction. Checking the body style, current wheel setup, and the appearance goal for the car will narrow the choice quickly and help avoid selecting a tire that belongs to a different MGB configuration.
What size rim does a 1974 MG MGB use?
The 1974 MG MGB uses a 14-inch rim across its primary tire fitments. That applies whether the car is using 165R14, 155R14, or 520-14 tires. Rim diameter stays consistent even though the available tire sizes and constructions vary by sub-model.
Diameter is only one part of wheel compatibility, so it still helps to confirm the actual wheel width on the car before choosing among available tires. That matters most when comparing the Roadster's radial and bias-ply options, since product specifications can vary by recommended rim-width range even when the tire size shares the same 14-inch wheel diameter.
Do all 1974 MG MGB sub-models use the same tire size?
No, the 1974 MG MGB sub-models do not all use the same tire size. The GT Coupe uses 165R14 radial tires, while the Roadster uses either 155R14 radial tires or 520-14 bias-ply tires. The shared point is the 14-inch rim, not a single common tire size.
That difference is important because the Roadster and GT Coupe should not be treated as one fitment group. A buyer standing in front of an MGB should confirm the exact body style first, then decide whether the car is being kept in its present construction type or moved toward a different tire approach that still suits the wheel and vehicle setup.
Choosing the Right Tire
What should I consider when choosing a tire for a 1974 MG MGB?
Start with the exact sub-model, because the 1974 MG MGB GT Coupe uses 165R14 radial tires, while the Roadster uses either 155R14 radial or 520-14 bias-ply tires. After that, compare construction, tire series, sidewall style, and any stated rim-width or load specification that applies to the size being considered.
A GT owner is mainly comparing among classic blackwall radial choices, while a Roadster owner may also be deciding between radial driving manners and a more traditional bias-ply presentation. Matching the tire to the car's current wheels, intended use, and restoration direction is usually more important than simply choosing by brand name alone.
What sidewall styles are available for 1974 MG MGB tires?
Sidewall style depends on tire size and construction. The radial 165R14 and 155R14 offerings are blackwall tires, while the 520-14 bias-ply choices are narrow whitewall tires. That means the sidewall appearance can change significantly depending on whether the car is a GT Coupe or a Roadster and whether it is running radial or bias-ply tires.
Appearance should be matched to the character of the specific car rather than chosen in isolation. A blackwall radial gives a classic sports-car presentation, while a narrow whitewall bias-ply creates a more stylized traditional look. Before making a change for appearance alone, confirm that the tire size and construction still suit the MGB's sub-model and wheel setup.
What brands offer tires for the 1974 MG MGB?
Brands available for the 1974 MG MGB include Pirelli, Michelin, Vredestein, Firestone, and Premium Sport. The 165R14 GT Coupe fitment is represented by Pirelli, Michelin, and Vredestein, the 155R14 Roadster radial fitment includes Michelin and Firestone, and the 520-14 bias-ply Roadster fitment centers on Premium Sport.
Brand choice should be made within the correct tire size first, then narrowed by tire series, sidewall style, and wheel compatibility. The available brands do not all overlap across every MGB fitment, so a buyer should think of them as size-specific options rather than expecting every brand to be available for both Roadster and GT configurations.
Restoration & Appearance
Which tire should I choose for a period-style 1974 MG MGB?
A period-style choice starts with the tire size and construction that belong to the specific 1974 MG MGB sub-model. The GT Coupe uses 165R14 radial tires, while the Roadster may use either 155R14 radial or 520-14 bias-ply tires. Those fitments create very different visual and driving presentations.
For a restoration-oriented car, the safest approach is to match the body style first, then decide how traditional the appearance needs to be. A Roadster owner may favor the 520-14 bias-ply look, while a GT owner is naturally pointed toward classic blackwall radials. Exact originality questions should be checked against marque-specific references if detail accuracy matters.
How does tire construction affect the appearance of a restored 1974 MG MGB?
Tire construction changes the visual character of a 1974 MG MGB as much as it changes the driving feel. The radial fitments, 165R14 and 155R14, are offered as blackwall tires, while the 520-14 bias-ply fitment is available with narrow whitewall styling. That creates a clear difference in sidewall presentation and overall period impression.
Construction choice should support the direction of the restoration rather than fight it. A car restored with a cleaner sports-car look may suit blackwall radials, while a Roadster leaning toward a more traditional visual treatment may benefit from the bias-ply whitewall appearance. Wheel width and the car's current setup still need to be verified before changing from one construction style to another.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1974 MG MGB?
Yes, modifications can affect tire fitment on a 1974 MG MGB even when the tire size itself is correct for the model. Changes such as aftermarket wheels, altered wheel width, suspension work, ride-height changes, or body clearance differences can all influence how a 165R14, 155R14, or 520-14 tire sits on the car.
Any MGB that has been changed from stock form should be checked at the wheel openings and through the steering range before new tires are chosen. Confirming the actual wheel diameter and width on the car is especially important on the Roadster, where both radial and bias-ply fitments exist and may have different wheel-compatibility considerations.
What should I inspect before driving a 1974 MG MGB on new tires?
Before driving a 1974 MG MGB on new tires, inspect the wheels for correct diameter and sound condition, make sure the tires are properly seated and inflated, and check for adequate clearance at the fenders and steering components. It also helps to verify that the chosen tire size matches the car's exact GT Coupe or Roadster fitment.
A short initial road check is wise on any collector-era car, especially one that may have older suspension parts or a long storage history. Look for rubbing, unusual vibration, or uneven stance after installation. Ongoing inspection should include tread condition, sidewall cracking, cuts, bulges, and air-loss checks so the MGB stays road-ready between drives.
How should tires on a collector 1974 MG MGB be maintained?
Tires on a collector 1974 MG MGB should be maintained with regular pressure checks, visual inspection, and careful storage habits. Whether the car uses 165R14, 155R14, or 520-14 tires, low annual mileage does not prevent aging. Sidewalls, tread, and valve areas should be checked routinely for cracking, cuts, bulges, or slow air loss.
Storage conditions matter on an MGB that spends long periods parked. Keeping the car away from prolonged sunlight, excess heat, moisture, and ozone sources helps preserve tire condition, and moving the car occasionally can reduce long-term flat spotting. Before a longer drive, inspect the full tire and wheel package again rather than assuming low-use tires are automatically ready.
