In 1978, MG was still delivering two very different expressions of the British sports car idea: the familiar, larger MGB and the smaller, lighter Midget. Both belonged to the late rubber-bumper era, when nimble handling, modest curb weight, and simple mechanical character remained central to the marque’s appeal. For 1978 MG vehicles, tire choice varies by model rather than being shared across the full range, with the MGB using 165R14 and the Midget using 145R13. That means the first step is identifying which MG you have, then confirming the correct 13- or 14-inch wheel before narrowing your choice to the right radial tire for originality, road manners, and overall character.
Which Tire Size Is Right for Your 1978 MG
Two tire sizes are used across 1978 MG vehicles, and they vary by model rather than carrying across the full range. The main decision is confirming whether your car takes the 13-inch Midget size or the 14-inch MGB size, since both choices are radial but they do not share the same rim diameter. Understanding that distinction before choosing a product saves time and helps ensure the right match.
Year(s): 1978|Fit(s): B|Construction: Radial|Rim: 14 in
165R14 is a euro-metric radial size with a 165-millimeter section width, an implied 80-series profile by convention, and fitment for a 14-inch wheel. It is available from Pirelli, Michelin, and Vredestein in blackwall form, with tubeless marking present on some products and H-rated versions carrying a 130 mph ceiling. This size is specific to the 1978 MGB rather than universal across the year and make. It suits owners who want the proper radial size for a late MGB while choosing among brands with slightly different period character and specification details.
Year(s): 1978|Fit(s): Midget|Construction: Radial|Rim: 13 in
145R13 is a euro-metric radial size with a 145-millimeter section width, an implied 80-series profile by convention, and fitment for a 13-inch wheel. It is available from Michelin and Firestone in blackwall form, and tube status varies by product because one tire is marked TL while another carries no tube marking in the size description. This size is specific to the 1978 MG Midget and is not shared with the MGB. It is the correct starting point for owners who want to preserve the Midget’s light, small-scale feel while staying with an era-appropriate radial format.
Two MG models are covered for 1978, and they do not use the same tire size. The practical takeaway is simple: year and make alone are not enough, because the MGB and Midget mount on different wheel diameters and require different tire sizes. Select your model below to narrow fitment history and product choices.
1978 MG B
The 1978 MGB was the mature, larger-displacement mainstay of the MG sports car line, known for its long production run and unmistakable British roadster character. Its tires mount on 14-inch wheels, giving it a distinct fitment path from the smaller Midget. For many owners, the right choice centers on preserving the MGB’s classic feel while matching the tire to the car’s intended road use and restoration goals.
The 1978 MG Midget was the smaller and more playful member of the MG lineup, with compact proportions that emphasized lightness and direct response. Its tires mount on 13-inch wheels, which immediately separates it from the MGB in fitment terms. Keeping the correct size matters not only for appearance, but also for maintaining the Midget’s small-car balance and steering character.
Five products are available across two tire sizes for 1978 MG vehicles. The 165R14 offers three radial choices from Pirelli, Michelin, and Vredestein in blackwall form, while the 145R13 offers two radial blackwall choices from Michelin and Firestone. Confirm your model first, since size, tube marking, and speed rating details can vary by product.
These FAQs cover the two-model split in 1978 MG tire sizing, how 145R13 and 165R14 differ, what blackwall radial choices are available, and what collectors should check before fitting or driving an MGB or Midget.
Size Basics & Fitment
What tire sizes fit 1978 MG vehicles?
1978 MG vehicles use two different tire sizes, depending on model. The 1978 MG MGB uses 165R14 on a 14-inch wheel, while the 1978 MG Midget uses 145R13 on a 13-inch wheel. Both are radial sizes, but they are not interchangeable because they mount on different rim diameters. Rim width guidance appears on some products, with 165R14 examples covering 4.0 to 6.0 inches and 145R13 examples covering 4.00 to 5.00 inches.
That means identifying the model is the first and most important step before choosing a tire for a 1978 MG. If you own an MGB, stay within the 165R14 family; if you own a Midget, stay within 145R13. After that, compare the actual wheel width against the tire’s approved range and confirm whether you want a tire with a more touring-oriented or more period-oriented character.
What does 165R14 mean on a 1978 MG tire?
On a 1978 MG, 165R14 is a euro-metric radial size. The 165 refers to nominal section width in millimeters, the R indicates radial construction, and the 14 is the wheel diameter in inches. In period sizing conventions, a metric size written this way usually implies an 80-series profile even when the aspect ratio is not printed directly. For 1978 MG applications, this size belongs to the MGB.
Understanding that code helps you avoid confusing a late-MGB radial with earlier British numeric or cross-ply sizes from other eras. It also explains why several tires in this size can look slightly different on paper while still remaining within the same general fitment family. Once you have confirmed 165R14 on the car, compare brand, rim-width compatibility, speed rating, and sidewall presentation to match how you actually use the MGB.
Do all 1978 MG models use the same tire size?
No. The 1978 MG MGB uses 165R14, while the 1978 MG Midget uses 145R13. Both cars use radial tires, but the difference in wheel diameter means the sizes are model-specific rather than shared across the marque. This is a true fitment distinction, not just a styling preference, and it reflects the physical difference between the larger MGB and the smaller Midget.
A buyer who knows only the year and make still needs to identify the exact model before moving ahead. That matters especially with MG, where the MGB and Midget can both appear in the same enthusiast search but follow different tire paths. If the car has changed hands or been restored, checking the wheel diameter on the vehicle is a smart final confirmation before selecting a tire.
Buying the Right Tire
What sidewall styles are available for 1978 MG tires?
Blackwall is the sidewall style available for both 1978 MG sizes. The 165R14 used on the MGB comes in blackwall form from Pirelli, Michelin, and Vredestein, and the 145R13 used on the Midget comes in blackwall form from Michelin and Firestone. That look suits the late-1970s sporting character of these cars and keeps the presentation understated and European in feel.
For most owners, that simplifies the visual decision because the key variables become brand, construction details within the radial category, and exact fitment rather than whitewall width or decorative sidewall treatment. If you are restoring a car for judged events, blackwall is the natural place to start, then confirm whether the event favors a particular tread pattern style or brand family associated with period European sports cars.
What brands make tires for 1978 MG vehicles?
Several well-known brands cover 1978 MG applications. The 165R14 MGB size is available from Pirelli, Michelin, and Vredestein, while the 145R13 Midget size is available from Michelin and Firestone. All of these options are radial tires, and all are offered as blackwalls. Within that shared format, the brand mix gives buyers a choice between classic European-style and traditional replacement-oriented offerings.
Brand selection usually comes down to the character you want the finished car to project and the exact specification you prefer. Some owners lean toward a European nameplate to reinforce the period sports-car feel, while others focus first on dimensions, load information, or wheel-width compatibility. Once the correct size is confirmed, comparing brands within that size is the best way to narrow the field without drifting into the wrong fitment.
What is the difference between Michelin XAS and Vredestein Sprint Classic for the 1978 MG MGB?
For the 1978 MG MGB in 165R14, both Michelin XAS and Vredestein Sprint Classic are radial blackwalls with H speed ratings, so both carry a 130 mph ceiling. The Michelin XAS is marked 165HR14 84H TL and fits rims from 4.50 to 6.00 inches, while the Vredestein Sprint Classic carries a maximum load of 1,102 pounds at 51 psi and fits rims from 4.0 to 5.5 inches. Their published weights also differ, with Michelin at 20 pounds and Vredestein at 16 pounds.
Those differences matter when you are matching a tire to the exact wheel on the car and to the feel you want from the finished setup. A wider approved rim-width span can be useful on cars with nonstandard wheel choices, while weight and load details may matter to owners who compare period-style touring use against a lighter-spec alternative. The smartest approach is to confirm wheel width first, then choose the tire whose dimensions and markings best align with your MGB.
Fitting & Setup
What rim width do 1978 MG tires require?
Rim width guidance for 1978 MG tires varies by size and by product. In 165R14 for the MGB, one radial fits 4.50 to 6.00-inch rims and another fits 4.0 to 5.5-inch rims. In 145R13 for the Midget, one radial fits 4.00 to 5.00-inch rims. Those ranges confirm that correct wheel width matters just as much as diameter when choosing among otherwise similar-looking classic tires.
Before fitting a tire, measure the wheel you plan to use rather than assuming every factory-style wheel is identical after decades of ownership changes. Steel wheels, aftermarket replacements, and restored wheels can vary. Staying within the approved width range helps preserve proper tread shape, steering response, and bead seating, especially on lighter British sports cars where small tire changes are easy to feel from behind the wheel.
Do 1978 MG tires require inner tubes?
Inner-tube use on 1978 MG tires depends on the exact product. In 165R14, Michelin XAS is marked TL, which identifies it as tubeless, while other products in the same size do not all carry the same tube marking in the size description. In 145R13, Michelin XAS FF is also marked TL, while the Firestone 145R13 does not carry the same marking. That makes tube status a product-specific detail rather than a one-answer rule for every 1978 MG tire.
The wheel itself matters too, especially on older British cars that may have original steel wheels, replacement wheels, or restored rims of varying condition. Confirm the tire marking, then confirm whether the wheel is intended for tubeless service and is in suitable condition to seal correctly. If there is any doubt, treat tube fitment as a deliberate setup decision rather than an assumption tied only to the tire size.
Maintenance, Storage & Longevity
How should I store a 1978 MG when the tires are fitted?
A 1978 MG stores best in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, and other ozone sources that can accelerate sidewall aging. Keep the tires properly inflated, clean off road grime, and avoid long exposure to standing moisture on concrete or soil. Because both 1978 MG tire sizes are radial, they generally tolerate storage better than older bias-ply designs, but they still benefit from periodic movement to prevent prolonged loading in one spot.
If the car will sit for an extended season, move it occasionally or use stands appropriately so the tires are not carrying the full weight in one position for months at a time. That is especially helpful on light sports cars with narrow tires, where a small flat area can be felt quickly on the first drive. Good storage habits protect appearance and ride quality just as much as tread depth does.
How long do tires on a 1978 MG typically last?
On a collector car such as a 1978 MG, tire age is usually more important than mileage. A sensible rule is to begin evaluating tires closely once they reach about five to seven years of age and to treat the ten-year mark as a point where replacement deserves serious consideration regardless of remaining tread. The DOT date code on the tire helps establish age, and any visible cracking, hardening, vibration, or loss of air retention shortens that timeline.
Many MGs cover limited annual mileage, so a tire can look usable while still aging out structurally. Owners often focus on tread because the car is driven sparingly, but time, storage conditions, and heat cycles matter more on enthusiast vehicles. If the tires came with the car and their age is uncertain, checking date codes should happen early in ownership rather than waiting for the first tour or highway trip.
How often should tires on a 1978 MG be inspected?
Tires on a 1978 MG should be inspected before every drive and again before any longer outing. Check inflation, tread wear, cuts, bulges, weather cracking, and any signs that the car has been sitting long enough to develop a temporary flat spot. On products marked tubeless, pay attention to valve stems and bead-sealing condition; where tube use is part of the setup, include the valve hardware and any unexplained pressure loss in the inspection routine.
Frequent inspection matters because narrow tires on light sports cars can mask age-related issues until road speed increases. A quick walkaround catches problems while they are still manageable and helps separate a simple pressure correction from a tire that is aging out. It also creates a useful habit before events, club drives, and seasonal wake-ups, when collector cars often go from static display to sustained road use in one day.
Restoration & Authenticity
What tires were originally fitted to the 1978 MG MGB?
A 1978 MG MGB would have been associated with radial construction in period, and the size used for the model here is 165R14. That aligns with the late-1970s shift toward radial tires as standard equipment on many European passenger cars and sports cars. Original-market details could still vary by destination, trim presentation, and wheel package, so the key authenticity markers are the correct size, correct radial construction, and an appropriate blackwall appearance rather than assuming one universal brand.
For a careful restoration, start with 165R14 and then refine the choice according to the way the car will be judged or displayed. Concours standards can differ between clubs, and British-car judges may pay attention to tread character, sidewall wording, and overall stance. If the car has a strong history or surviving original literature, compare that evidence with guidance from marque specialists before making a final authenticity decision.
Does correct tire fitment matter for showing a 1978 MG?
Correct tire fitment matters on a 1978 MG because judges and knowledgeable enthusiasts notice size, construction type, and sidewall appearance very quickly. On these late MGs, using the proper model-specific size is the first requirement: 165R14 for an MGB and 145R13 for a Midget. Blackwall radial construction fits the late-1970s character of the marque, while an obviously incorrect wheel diameter or a size that changes the car’s stance can stand out immediately.
Show expectations vary from relaxed local events to highly particular marque judging, so authenticity should be matched to the event rather than assumed. Some owners prioritize overall period appearance, while others want exact replication of the car’s delivery-era tire type. If trophies matter, verify the judging standard in advance and use club knowledge to decide how closely your tire choice should follow original market practice.
What is the difference between Michelin XAS FF and Firestone F560 Radial Tire for the 1978 MG Midget?
For the 1978 MG Midget in 145R13, Michelin XAS FF and Firestone F560 are both blackwall radial choices, but their published details are not identical. The Michelin carries a 145HR13 74H TL marking, which means it is H-rated to 130 mph and marked tubeless, while the Firestone includes a maximum load figure of 825 pounds at 44 psi and a rim-width range of 4.00 to 5.00 inches. Their weights differ as well, with Michelin at 18 pounds and Firestone at 12.7 pounds.
Those differences shape the final decision for a Midget owner who wants more than a simple size match. One buyer may care most about speed rating and the classic Michelin pattern, while another may focus on wheel-width compatibility or a lighter published tire weight. Since the Midget is sensitive to small changes in tire feel, it is worth matching the tire to the exact wheel and the car’s intended use rather than choosing by brand name alone.
Safety & Road Use
Are 1978 MG tires safe for highway driving?
1978 MG tires can be suitable for highway driving when they are the correct size, properly fitted, in sound condition, and used within their speed and load capabilities. Among the products here, H-rated versions of both 165R14 and 145R13 are available, and an H rating carries a 130 mph ceiling. At ordinary U.S. highway speeds, the mechanical condition of a late-1970s MG, including suspension, steering, brakes, and alignment, is often just as important as the tire’s nominal speed capability.
Highway confidence starts with matching the tire to the right model and wheel, then confirming age, inflation, and overall condition before the trip. A well-kept MGB or Midget on the proper radial tire can feel stable and predictable, but these are still lightweight vintage sports cars with old-car responses and road manners. Think of the tire as one part of a complete system rather than the sole measure of safety.
What inflation pressure should I use for 1978 MG tires?
Inflation pressure for a 1978 MG should be set with two references in mind: the vehicle manufacturer’s recommended pressure for the car and the tire manufacturer’s maximum load-and-pressure marking for the exact tire. One 165R14 tire carries a maximum load of 1,102 pounds at 51 psi, while one 145R13 tire carries a maximum load of 825 pounds at 44 psi. Those figures describe the tire’s rated limit for that product, not a universal running pressure for every 1978 MG application.
The right day-to-day pressure is usually lower than the maximum figure and should be chosen according to the specific MG model, wheel, and tire. Do not transfer a pressure from the MGB’s 165R14 to the Midget’s 145R13, or from one tire brand to another without checking the sidewall and the car’s own recommendations. If originality literature is available, use it as your baseline and fine-tune only within the tire maker’s approved limits.
What should I check before taking a 1978 MG on a longer drive?
Before a longer drive in a 1978 MG, inspect all four tires and the spare for pressure, cracking, tread condition, cuts, bulges, and age. Confirm that the car is wearing the correct size for its model, with 165R14 on an MGB or 145R13 on a Midget, and make sure the valve stems and wheel sealing surfaces are in good order. If your setup involves tube-related hardware, include that in the inspection rather than focusing only on tread and sidewall appearance.
A proper pre-drive check goes beyond tires, but the tires are where many long-stored collector cars reveal trouble first. Narrow, classic-sized radials can lose pressure gradually, develop age cracks, or expose a weak spare only when you need it most. Pair the tire inspection with checks of brakes, fluids, cooling, and lights so the car’s vintage charm does not get in the way of a reliable day on the road.
