1968 MG Tire Fitment Guide

1968 MG vehicles use seven sizes across four models. The MG 1100 uses 145R12 or 5.50-12 on 12-inch wheels, the MG model uses 165R14 or 5.90-14 on 14-inch wheels, the MGB uses 165R14, 155R14, or 520-14 on 14-inch wheels, and the Midget uses 145R13 on 13-inch wheels. Rim-width guidance is available within some product ranges: 145R12 appears at 4.5 inches, 165R14 spans 4.0 to 6.0 inches depending on tire, 155R14 spans 4.00 to 5.50 inches, 520-14 spans 3.50 to 4.00 inches, and 145R13 spans 4.00 to 5.00 inches.

That spread means year and make alone are not enough for a confident tire choice. A 1968 MG owner should identify the exact model first, then match the wheel diameter, then narrow the decision to radial or bias-ply where both constructions are relevant. The MGB and MG fitments are especially easy to confuse because both use 14-inch wheels, but the actual size family and intended look can still differ.

On a 1968 MG, 5.20-14 is a numeric bias-ply size. The 5.20 figure refers to the tire’s nominal section width in inches, while the 14 identifies the wheel diameter in inches. On this year’s MG range, 520-14 is tied to the MGB and represents a traditional bias-ply fitment rather than a modern metric radial code.

That matters because a numeric bias-ply size is chosen differently than a metric radial. A buyer considering 520-14 for a 1968 MG MGB is usually prioritizing period appearance, classic sidewall shape, and era-correct construction. Before choosing it over a 155R14 or 165R14 radial, confirm the wheel dimensions and decide whether the car is being judged for authenticity or driven mainly for road enjoyment.

No. The 1968 MG range is split across 12-inch, 13-inch, and 14-inch wheel diameters, and each model has its own fitment path. The 1100 is separate from the sports-car line, the Midget uses its own 145R13 radial size, and the MG and MGB share one 165R14 radial option while also carrying model-specific alternatives.

That model-to-model variation is more than a detail; it is the first filter in the buying process. If you start with year and make but skip model identification, it is easy to end up comparing a Midget radial against an MGB bias-ply size that will not mount on the same wheel. Once the model is confirmed, the remaining decision becomes much more manageable.

For a 1968 MG MGB, the difference between 520-14 and 165R14 is primarily construction and character. The 520-14 is a bias-ply size with narrow whitewall offerings from Premium Sport, while the 165R14 is a radial available as a blackwall from Pirelli, Michelin, and Vredestein. The 165R14 also carries H-rated options with a 130 mph ceiling in this application.

A buyer restoring an MGB with an emphasis on period-style visual presentation will often lean toward the bias-ply 520-14, especially when the whitewall look is part of the car’s intended finish. A buyer using the car regularly on modern roads will often prefer the 165R14 radial. The choice is less about one being universally better and more about matching the tire’s construction and appearance to the car’s mission.

1968 MG tires span two basic sidewall presentations in the currently covered sizes. The radial sizes 145R12, 165R14, 155R14, and 145R13 are available as blackwalls, while the 520-14 bias-ply range for the MGB appears with narrow whitewall styling. That gives the year a clear split between understated sports-car blackwalls and a more decorative vintage whitewall option.

For most late-1960s MG applications, blackwalls are the safer visual match when originality is the goal, especially on British sports models driven by enthusiast buyers. Narrow whitewalls can still suit certain presentation choices, particularly on a car built for a distinct period look rather than strict factory-style authenticity. Sidewall appearance should be chosen alongside size and construction, not as an afterthought.

1968 MG coverage includes Michelin, Pirelli, Vredestein, Firestone, and Premium Sport, depending on size. Michelin covers 145R12, 165R14, 155R14, and 145R13; Pirelli and Vredestein appear in 165R14; Firestone appears in 155R14 and 145R13; and Premium Sport covers the 520-14 bias-ply whitewall range. Brand availability follows the size family rather than the make as a whole.

That means the best first question is not which brand to choose, but which size your 1968 MG actually uses. Once the model and size are settled, brand preference can be narrowed by construction type, sidewall style, and how close you want the tire to feel to a period European fitment. The broadest brand choice sits in 165R14, while the smaller-model sizes are naturally more focused.

Rim-width guidance varies by size on 1968 MG applications. The 145R12 appears on a 4.5-inch rim, 165R14 spans 4.0 to 6.0 inches depending on the tire, 155R14 spans 4.00 to 5.50 inches, 520-14 spans 3.50 to 4.00 inches, and 145R13 spans 4.00 to 5.00 inches. Those ranges show that even within the same rim diameter, acceptable wheel width can differ meaningfully by size and product.

That is especially important on 14-inch MG applications, where a buyer may be comparing 165R14, 155R14, and 520-14 on cars that all look outwardly similar. A wheel that accepts one 14-inch size is not automatically ideal for every other 14-inch size. Before final selection, compare the actual wheel width on the car to the specific tire’s approved range rather than relying on diameter alone.

Tube requirements on 1968 MG tires vary by size and product. The 145R12 Michelin MX and the 155R14 Michelin X are marked TL for tubeless use, and the 145R13 Michelin XAS FF is also marked TL. In other sizes, the tube status is not uniform across every product description, so it should be treated as something to confirm on the exact tire you are considering rather than assumed for the entire size family.

Inner-tube decisions also depend on the wheel itself, not only the tire. Original wheel condition, wheel design, and restoration quality all influence whether a tubeless tire can be run as intended or whether tube use becomes part of the setup. For a 1968 MG with older wheels, confirm both the tire marking and the wheel’s suitability before mounting.

Original 1968 MG wheels can only be used with tire sizes that match the wheel’s diameter and fall within an appropriate width range. The year spans 12-inch, 13-inch, and 14-inch applications, so an MG 1100 wheel cannot interchange directly with a Midget or MGB tire size. Even within the 14-inch group, the width needs of 520-14, 155R14, and 165R14 are not identical.

That makes wheel verification just as important as size decoding. If the car still wears its original wheels, confirm the diameter first and measure the rim width before choosing between different 14-inch options. If the wheels have been changed at some point in the car’s life, inspect the actual wheels on the car rather than assuming they match factory dimensions for that model.

A 1968 MG should be stored out of direct sunlight, away from electric motors, chargers, furnaces, and other ozone sources, with the tires kept clean and dry. If the car will sit for an extended period, maintain proper inflation and either move it periodically or support it in a way that reduces long-term loading on one contact patch. Bias-ply tires tend to flat-spot more readily during static storage than radials, so that matters most on fitments such as 5.50-12, 5.90-14, or 520-14.

Collector cars often age their tires more from storage conditions than from mileage. A climate-stable garage and occasional repositioning can do more for longevity than simply leaving the car parked for months at a time. If your 1968 MG is driven only seasonally, include tire condition in the spring recommissioning routine rather than focusing only on fluids and battery health.

Tires on a 1968 MG should be judged more by age and condition than by miles traveled. A sensible collector-car rule is to begin closer evaluation around the five-to-seven-year point and to treat around ten years as a serious replacement threshold, even if tread depth still looks usable. The DOT date code and the tire’s overall condition matter far more than how often the car leaves the garage.

That age-based approach is especially important on low-use British classics, where a set can look presentable long after the rubber has begun to harden. Sidewall cracking, loss of pliability, repeated pressure loss, or vibration after the car has been driven enough to warm the tires are stronger warning signs than odometer mileage. A lightly used tire is not automatically a young tire.

Tires on a 1968 MG deserve a quick inspection before every drive and a more careful inspection before any longer outing. Look for sidewall cracking, tread damage, cuts, bulges, irregular wear, and signs of air loss, and confirm that pressures are stable. On applications that may involve tube-type use or older wheel hardware, valve stems and tube-related service items deserve the same attention as the tread and sidewall.

A short pre-drive walkaround often catches problems early, especially on a car that may sit for weeks between outings. Before a tour or highway trip, inspect the spare as well, since a decades-old spare is often forgotten until it is needed. On a vintage MG, tire inspection should be part of the same habit as checking fluids, lights, and brake feel.

A 1968 MG MGB was originally from the bias-ply-to-radial transition era, so construction type is part of the authenticity conversation. Within this year’s MGB coverage, both radial sizes such as 165R14 and 155R14 and a bias-ply size, 520-14, appear in the fitment picture. That makes it important to separate what is broadly period-appropriate from what is correct for a specific market, trim presentation, or restoration target.

For a factory-authentic restoration, the safest approach is to confirm the car’s original delivery market and consult an MG marque specialist or club resource before finalizing the exact construction and sidewall style. The broad rule is simple: a radial can be entirely era-appropriate for a late-1960s MG, while a bias-ply tire still matters when the restoration standard leans toward earlier-correct visual cues or event-specific judging expectations.

Correct tire fitment absolutely matters when a 1968 MG is judged for originality. Judges and knowledgeable enthusiasts look at size, construction type, sidewall treatment, and overall visual proportion, not just whether the tire physically fits the wheel. A blackwall radial in the right family can read very differently from a narrow-whitewall bias-ply, even when both mount on a 14-inch wheel.

That means the right show tire depends on what kind of event the car is entering. A local enthusiast show may allow more latitude, while marque judging can be far stricter about sidewall style and construction. If points matter, verify the event’s standards and compare them against your exact 1968 MG model before making a final choice, especially on MGB applications where more than one fitment path exists.

For a 1968 MG MGB in 155R14, Michelin X and Firestone F560 Radial occupy the same basic size and both use blackwall radial construction, but their supporting details differ. The Michelin carries an 80T TL marking, indicating a tubeless T-rated radial with a 118 mph ceiling. The Firestone F560 Radial includes a 4.00 to 5.50-inch rim-width range and a maximum load figure of 990 pounds at 44 psi.

In practical terms, the decision comes down to the exact details you value within the same size family. One buyer may prioritize a tire with an explicit speed symbol and tubeless marking, while another may focus on the published rim-width range and load figure when matching the tire to an existing wheel. Either way, the comparison should stay within the confirmed 155R14 fitment for the MGB rather than crossing into a different size.

1968 MG tires can be suitable for highway driving when the correct size, sound wheel, proper inflation, and a healthy vehicle are all part of the equation. The radial ranges include S-, T-, and H-rated examples, with ceilings of 112 mph, 118 mph, and 130 mph respectively where those markings appear. On a classic MG, ordinary highway use is usually shaped more by the car’s age, braking system, steering, suspension condition, and alignment than by the top-speed rating alone.

The more important question is whether the entire car is prepared for sustained road use. A fresh, correctly inflated radial on worn suspension bushings or an out-of-round wheel will not deliver the confidence a buyer expects. Before regular highway driving, treat the tires as one part of a complete mechanical picture rather than as the only safety variable.

Inflation pressure for a 1968 MG should follow the factory recommendation for the specific model and size, then be cross-checked against the tire maker’s own maximum-rated figures where they are published. Available figures in this range include 165R14 at 1,102 pounds at 51 psi on one Vredestein option, 155R14 at 990 pounds at 44 psi on one Firestone option, 520-14 at 1,230 pounds at 60 psi on certain Premium Sport versions, and 145R13 at 825 pounds at 44 psi on one Firestone option.

Those figures are load-and-maximum-pressure references, not a blanket operating pressure for every 1968 MG. Do not transfer a number from one size to another, and do not assume a maximum sidewall pressure is the correct running pressure for a light British car. Use the car’s manual and the exact tire’s specifications together, especially if the car has changed sizes or wheels over the years.

Before a longer drive in a 1968 MG, inspect each tire for cracking, cuts, bulges, exposed cords, uneven wear, and proper inflation, then check that the spare is usable and inflated as well. If your setup involves tube-type service or older wheel hardware, inspect valve stems and any recent mounting work closely. A tire that looks acceptable parked in the garage can reveal age or pressure issues quickly once the car is driven at speed.

Longer trips also call for a broader mechanical check that fits the age of the car. Confirm fluid levels, brake feel, steering response, wheel-nut torque, and basic lighting before departure. On a vintage MG, confidence comes from the combination of healthy tires and a sound chassis, not from any single part being new.