By 1966, MG offered a broad slice of British motoring, from the compact 1100 sedan to the open-top Midget and the better-known MGB sports car. That variety means 1966 MG tire fitment is not one-size-fits-all: four models use seven distinct sizes, with both radial and bias-ply options appearing across the range rather than a single universal fitment. Some models, such as the 1100 and Midget, use smaller-diameter wheels, while the larger MG and MGB share 14-inch applications with different period tire conventions. Before choosing a tire for a 1966 MG, confirm the exact model first, then decide whether originality or more modern road manners matters more to you.
Which Tire Size Is Right for Your 1966 MG
Seven tire sizes appear across the 1966 MG range, and they vary by model rather than carrying across every car in the lineup. The key decision is identifying the correct model and wheel diameter first, then choosing between period-style bias-ply sizing and radial alternatives where both types exist for the same application. Understanding that distinction before choosing a product saves time and helps match the tire to the right car.
Year(s): 1966|Fit(s): 1100|Construction: Radial|Rim: 12 in
145R12 is a metric radial size with a 145-millimeter section width and a 12-inch rim diameter; in this older euro-metric style, the aspect ratio is conventionally an 80-series even though it is not written into the code. This size is specific to the 1966 MG 1100 and is available as a Michelin blackwall tubeless radial with an S speed rating, good to 112 mph. It suits an owner who wants a radial construction on the 1100 without moving away from the car's compact original wheel diameter.
Year(s): 1966|Fit(s): 1100|Construction: Bias Ply|Rim: 12-in rim
5.50-12 is a numeric bias-ply size in which 5.50 refers to nominal section width and 12 is the rim diameter in inches. This size is specific to the 1966 MG 1100. It is the period-style choice for owners focused on maintaining the original bias-ply character of the 1100 rather than moving to a radial alternative.
Year(s): 1966|Fit(s): 1966 MG, B|Construction: Radial|Rim: 14 in
165R14 is a metric radial size with a 165-millimeter section width and a 14-inch rim diameter; as an older euro-metric designation, it conventionally represents an 80-series profile. This size is used by the 1966 MG and 1966 MGB, and it is available from Pirelli, Michelin, and Vredestein in blackwall form; speed ratings vary by product, with H-rated versions carrying a 130 mph ceiling. It is the radial option for these 14-inch MG applications and appeals to drivers who want a later radial feel while staying within a period-appropriate size family.
Year(s): 1966|Fit(s): 1966 MG|Construction: Bias Ply|Rim: 14-in rim
5.90-14 is a numeric bias-ply size in which 5.90 indicates nominal section width and 14 is the rim diameter in inches. This size is specific to the 1966 MG rather than universal across the full year and make range. It is the more traditional bias-ply fitment path for that model when restoration character matters more than a switch to radial construction.
Year(s): 1966|Fit(s): B|Construction: Bias Ply|Rim: 14 in
560-14 is a numeric bias-ply size with a nominal 5.60-inch section width and a 14-inch rim diameter. This size is specific to the 1966 MGB and is available from BFGoodrich in blackwall, narrow whitewall, and wide whitewall versions, all as bias-ply tires with load ratings of 906 pounds at 30 psi. It is the period-style choice for an MGB owner who wants an authentic bias-ply look, with sidewall appearance becoming the main visual decision within the size.
Year(s): 1966|Fit(s): Midget|Construction: Radial|Rim: 13 in
145R13 is a metric radial size with a 145-millimeter section width and a 13-inch rim diameter, using the older euro-metric convention that typically implies an 80-series profile. This size is specific to the 1966 MG Midget and is available in blackwall form from Michelin and Firestone; one Michelin version is tubeless and H-rated, with a 130 mph ceiling. It is the radial route for Midget owners who want to keep the original wheel diameter while using a more modern construction.
Year(s): 1966|Fit(s): Midget|Construction: Bias Ply|Rim: 13 in
520-13 is a numeric bias-ply size in which 5.20 denotes nominal section width and 13 is the rim diameter in inches. This size is specific to the 1966 MG Midget and comes from Firestone and Premium Sport in blackwall and narrow whitewall styles, with published load figures ranging from 770 pounds at 32 psi to 1,100 pounds at 60 psi on the products that carry load markings. It fits the Midget owner looking for a traditional small-sports-car bias-ply appearance, especially when sidewall style is part of the car's finished look.
Four MG models are covered for 1966, and tire size changes with the model rather than staying the same across the whole make. That means year and make alone are not enough here; the 1100, MG, MGB, and Midget each need the correct wheel diameter and size family confirmed before moving on to tire selection. Select your model below to narrow the fitment history and see the matching tire options.
1966 MG 1100
The MG 1100 was MG's compact front-wheel-drive sedan, sharing the era's small British-car mission but in a more practical everyday package than the marque's sports cars. Its tires mount on 12-inch wheels, and the choice centers on a radial 145R12 or a period-style 5.50-12 bias-ply depending on how original or updated you want the driving experience to feel.
The 1966 MG entry reflects a 14-inch application within the broader MG lineup, separate from the smaller 1100 and Midget wheel packages. Its tires mount on 14-inch wheels, with a 165R14 radial option alongside the more traditional 5.90-14 bias-ply fitment for owners balancing road use against period presentation.
By 1966, the MGB had firmly established itself as MG's mainstream sports car, known for its clean proportions and approachable roadster formula. It uses 14-inch tires, with 165R14 as the radial path and 560-14 as the traditional bias-ply size, so the decision is less about wheel diameter than about the character you want the car to present and deliver.
The Midget was MG's smallest and lightest open sports car, prized for simple mechanicals and nimble proportions. Its tires mount on 13-inch wheels, and it can be matched with a 145R13 radial or a 520-13 bias-ply depending on whether the goal is traditional appearance or a more updated construction style.
Thirteen products are available across seven tire sizes for 1966 MG vehicles. 145R12 has one Michelin radial blackwall; 165R14 has three radial blackwalls from Pirelli, Michelin, and Vredestein; 560-14 has three BFGoodrich bias-ply choices in blackwall, narrow whitewall, and wide whitewall; 145R13 has two radial blackwalls from Michelin and Firestone; 520-13 has four bias-ply choices from Firestone and Premium Sport in blackwall and narrow whitewall. Confirm your model, size, and construction preference before selecting.
These answers sort out the model-by-model size differences across 1966 MG cars, the bias-ply versus radial decision on shared applications, sidewall appearance choices on certain sizes, and the care collector tires need when the car spends more time parked than driven.
Size Basics & Fitment
What tire sizes fit 1966 MG vehicles?
1966 MG vehicles use seven sizes across four models. The 1100 uses 145R12 or 5.50-12 on 12-inch rims, the MG uses 165R14 or 5.90-14 on 14-inch rims, the MGB uses 165R14 or 560-14 on 14-inch rims, and the Midget uses 145R13 or 520-13 on 13-inch rims. Where rim-width guidance appears, 145R12 uses a 4.5-inch rim, 165R14 fits 4.0 to 6.0-inch rims depending on product, 560-14 fits 3.50 to 4.00-inch rims, 145R13 fits 4.00 to 5.00-inch rims, and 520-13 fits 3.5 to 4.00-inch rims depending on product.
The practical takeaway is that a 1966 MG buyer must identify the exact model before picking a size. There is some overlap in construction choices within a model, especially on the 14-inch cars, but the wheel diameter itself changes across the lineup. Once the model is confirmed, the next decision becomes whether you want the traditional bias-ply style associated with the era or a radial in the same general size family for a different road feel.
What does 165R14 mean on a 1966 MG tire?
On a 1966 MG, 165R14 is an older euro-metric radial size. The 165 is the section width in millimeters, the R identifies radial construction, and the 14 is the wheel diameter in inches. In this style of sizing, the aspect ratio usually is not printed even though it is commonly treated as an 80-series profile. Within the 1966 MG range, 165R14 applies to the MG and the MGB, both of which use 14-inch wheels.
That matters because 165R14 is not just a generic modern size substitute; it is the radial-size path for specific 14-inch MG applications. If you are comparing it with 5.90-14 or 560-14, you are really comparing construction style and fitment family within a model rather than trying to move to a different wheel diameter. It is a sensible place to start if your car is an MG or MGB and you want a radial without stepping outside the proper 14-inch format.
Do all 1966 MG models use the same tire size?
No. A 1966 MG does not use one universal tire size across the whole make. The 1100 is a 12-inch application, the MG and MGB are 14-inch applications, and the Midget is a 13-inch application. Even where two models share the same radial size, such as 165R14 on the MG and MGB, the bias-ply alternatives differ, with 5.90-14 tied to the MG and 560-14 tied to the MGB.
That means year and make alone are not enough to choose correctly. If you own a sports car, a compact sedan, or a small roadster from MG's 1966 lineup, the tire conversation starts with the exact model and wheel diameter. Once that is settled, then you can compare sidewall style, construction type, and brand choice without risking a mismatch between tire and wheel.
Buying the Right Tire
Should I choose the 165R14 or the 560-14 for my 1966 MG?
For a 1966 MG MGB, the choice between 165R14 and 560-14 is mainly a choice between radial and bias-ply construction on a 14-inch wheel. The 165R14 is offered as a radial blackwall from Pirelli, Michelin, and Vredestein, while the 560-14 is a bias-ply from BFGoodrich in blackwall, narrow whitewall, and wide whitewall form. The radial and bias-ply options represent different eras of tire design more than two arbitrary size labels.
Owners focused on period presentation generally gravitate toward the bias-ply size that matches the car's original-era look, while owners who prioritize a later-style radial construction often prefer the 165R14. The same logic applies to the 1966 MG model that pairs 165R14 with 5.90-14. The best choice depends on whether your car is being restored for authenticity, shown, or driven regularly in ways that make radial construction attractive.
What sidewall styles are available for 1966 MG tires?
Most 1966 MG radial applications are blackwall tires. The 145R12, 165R14, and 145R13 products are all blackwalls. The strongest sidewall-style variation appears in the bias-ply sizes, especially 560-14 for the MGB, which comes in blackwall, narrow whitewall, and wide whitewall versions, and 520-13 for the Midget, which appears in blackwall and narrow whitewall form.
For a British sports car of this era, blackwalls usually align most naturally with a factory-sporting look, while whitewall choices shift the visual character in a more stylized direction. That does not automatically make a whitewall wrong, but it does make the sidewall a visible part of the car's presentation. If appearance matters as much as fitment, decide on the sidewall style at the same time you choose between radial and bias-ply construction.
What brands make tires for 1966 MG vehicles?
1966 MG tire coverage includes Michelin, Pirelli, Vredestein, BFGoodrich, Firestone, and Premium Sport. Michelin covers 145R12, 165R14, and 145R13; Pirelli and Vredestein appear in 165R14; BFGoodrich appears in 560-14; Firestone appears in 145R13 and 520-13; and Premium Sport appears in 520-13. The result is a mix of European-style radial offerings and traditional bias-ply lines depending on the model and size family.
Brand choice should come after model and size are confirmed, not before. A buyer with an MGB shopping 14-inch fitment has a different brand landscape than a Midget owner on 13-inch tires, and a 1100 owner has a narrower path still. Once the correct size is settled, brand becomes a way to refine period feel, sidewall appearance, and the overall style of the finished tire package.
Fitting & Setup
What rim width do 1966 MG tires require?
Rim-width guidance varies by size. The 145R12 Michelin radial uses a 4.5-inch rim. In 14-inch fitment, 165R14 products cover ranges from 4.0 to 5.5 inches or 4.50 to 6.00 inches depending on brand, while 560-14 bias-ply tires fit 3.50 to 4.00-inch rims. In 13-inch fitment, 145R13 fits 4.00 to 5.00-inch rims, and 520-13 ranges from a 3.5-inch rim to 3.50 to 4.00 inches depending on product.
That spread is wide enough that wheel confirmation matters before you commit to a specific tire, especially on 14-inch and 13-inch applications where multiple products exist. Even when two tires share the same rim diameter, they may not share the same ideal rim-width range. Check the actual wheel on the car rather than relying only on memory, especially if the car has been restored or modified at some point in its life.
Do 1966 MG tires require inner tubes?
Tube status can vary by size and product. The 145R12 Michelin MX is marked TL, and the 145R13 Michelin XAS FF is also marked TL, indicating tubeless construction. The 165R14 family includes tubeless-marked products as well, but not every entry carries the same style of marking. The bias-ply sizes shown here do not all carry explicit tube notation in the size field, so they should be checked product by product before final installation planning.
That matters because tube fitment is not determined by tire construction alone; it also depends on the wheel design and the exact tire selected. An older wheel that was designed around tube-type service may still call for a different approach than a later tubeless-compatible wheel, even if a radial tire is available in the same nominal size family. Confirm the tire marking and inspect the wheel itself before deciding on tubes, stems, and final setup.
Can the original 1966 MG wheels be used with both tire sizes for each model?
Within each 1966 MG model, the paired bias-ply and radial choices use the same wheel diameter. The 1100 stays on 12-inch tires, the MG and MGB stay on 14-inch tires, and the Midget stays on 13-inch tires. That means the size decision within a model is not a change from one wheel diameter to another, but it does not automatically mean every original wheel is equally suitable for every product without checking rim width.
The safe approach is to treat diameter compatibility as only the first checkpoint. A 14-inch wheel on an MGB may accept either a 165R14 radial or a 560-14 bias-ply in principle, but the exact wheel width still needs to fall within the tire maker's approved range. If the car has aftermarket wheels or has changed hands many times, confirm the actual wheel dimensions before assuming the original setup is still in place.
Maintenance, Storage & Longevity
How should I store a 1966 MG when the tires are fitted?
A 1966 MG should be stored away from direct sunlight, electric motors, ozone-producing equipment, standing moisture, and major temperature swings. Clean, dry concrete or a barrier between the tire and bare floor is preferable, and the car should be moved periodically so it does not sit on one footprint for long stretches. Bias-ply tires in particular can develop temporary flat spotting more readily during static storage, while any collector tire can suffer sidewall weathering if left near ozone and UV exposure.
Storage habits matter more on collector cars than mileage does, because many MGs spend long periods parked between drives. If the car will sit for months, maintaining proper inflation and reducing prolonged load on one spot can help preserve the casing and sidewall appearance. Owners using a bias-ply setup for show-oriented authenticity should be especially careful about storage routine, since those tires tend to show neglect sooner in day-to-day use.
How long do tires on a 1966 MG typically last?
On a 1966 MG, age is usually a more important factor than tread wear. Collector-car tires often need evaluation around the five- to seven-year mark and deserve serious replacement consideration as they approach ten years from the date code, even if the tread still looks serviceable. That applies to both radial and bias-ply construction, because rubber hardening, internal aging, and sidewall cracking can develop long before the tire appears worn out by mileage.
The practical rule is to inspect the DOT or production date code, watch for cracking and stiffness, and avoid judging condition by tread depth alone. A lightly used Midget or MGB that sees fair-weather driving can still be riding on old tires that have aged beyond their ideal service window. If the car's driving pattern is occasional and seasonal, calendar age should stay at the center of your replacement planning.
How often should tires on a 1966 MG be inspected?
Tires on a 1966 MG should be inspected before every drive and more carefully before any longer outing. Look for sidewall cracking, cuts, bulges, irregular tread wear, signs of impact damage, and any loss of air pressure since the last use. On sizes that may involve tube-type service or older wheel designs, valve stems and the general condition of the wheel well deserve attention too, because a collector car often reveals age-related issues before it reveals wear-related ones.
A quick walkaround catches more than many owners expect, especially on cars that are not driven weekly. An MGB or Midget that was perfectly fine on the last outing may still develop a pressure loss, sidewall split, or stem issue while parked. Building tire inspection into the same routine as checking fluids, brakes, and lighting is one of the easiest ways to make an older MG more dependable on the road.
Restoration & Authenticity
What tires were originally fitted to the 1966 MG MGB?
For a 1966 MG MGB, bias-ply construction is the safest original-era starting point because that was still the mainstream factory fitment style for many mid-1960s sports cars. Within the 1966 MG range, the MGB's period-style size is 560-14, while 165R14 represents the radial alternative used in the same 14-inch family. Original-equipment brand should not be assumed from reproduction availability alone, since market, destination, and prior restoration choices can all influence what a specific car wore when new.
If your goal is authenticity, begin with the original-style size and construction before worrying about brand. Sidewall appearance also matters, since an MGB presented for originality usually looks most at home on a conservative period sidewall rather than a stylized custom treatment. For concours-level accuracy, confirm the exact expectation with an MG marque club or event judge, especially if your car's history includes export-market variations or earlier restoration work.
Does correct tire fitment matter for showing a 1966 MG?
Yes, correct tire fitment matters on a 1966 MG because judges and knowledgeable enthusiasts often notice size, construction type, and sidewall appearance immediately. A car restored around period authenticity can lose credibility if it wears the wrong wheel diameter, an obviously later construction style, or a sidewall treatment that looks out of character for the model and era. On the 1966 MG range, that issue is especially important because the 1100, MG, MGB, and Midget do not all share the same tire package.
The first step is matching the correct model to the correct size family, then deciding whether the car is being judged for originality or simply presented as a well-kept driver. A radial may be entirely sensible for regular road use, but a strict originality-minded event may favor the bias-ply style associated with the period. Event standards vary, so serious show preparation should include checking the rules and consulting marque-specific judging references.
What is the difference between BFGoodrich blackwall and whitewall 560-14 tires for the 1966 MG?
For the 1966 MG MGB, the BFGoodrich 560-14 options share the same basic bias-ply construction, 14-inch rim diameter, 3.50 to 4.00-inch rim-width range, and 906-pound load rating at 30 psi. The main difference is sidewall presentation: one is blackwall, one uses a narrow whitewall, and one uses a wide whitewall. Weight varies slightly between versions, with the blackwall at 17 pounds and the whitewall versions at 18 pounds.
That makes the choice mostly visual rather than structural. A blackwall usually suits the MGB's sporting personality more naturally, while a narrow or wide whitewall shifts the car's appearance toward a more personalized period look. If your MGB is being restored with authenticity in mind, sidewall style deserves the same attention as size and construction, because it changes how the car reads at a glance even when the fitment itself is correct.
Safety & Road Use
Are 1966 MG tires safe for highway driving?
1966 MG tires can be suitable for highway driving when the size, condition, and construction match the car and the intended use. The radial sizes here include S-rated and H-rated examples, with S carrying a 112 mph ceiling and H carrying a 130 mph ceiling. Those figures are well above normal highway cruising, but a mid-1960s MG's braking, suspension condition, alignment, and overall mechanical health remain just as important as the tire's speed capability.
The real question is not whether the tire alone has enough top-end rating, but whether the entire car is prepared for sustained road use. A fresh radial on an MGB or Midget may feel different from a bias-ply setup, yet either construction still needs proper inflation, sound steering components, and a chassis in good order. Highway use starts with selecting the right size, then making sure the rest of the car is equally ready for the trip.
What inflation pressure should I use for 1966 MG tires?
Inflation pressure on a 1966 MG should begin with the factory recommendation for the exact model, then be cross-checked against the tire maker's rated information for the specific product. Several sizes here carry published load-and-pressure figures: 560-14 is rated at 906 pounds at 30 psi, 165R14 appears with 1,102 pounds at 51 psi on one product, 145R13 appears with 825 pounds at 44 psi on one product, and 520-13 ranges from 770 pounds at 32 psi to 1,100 pounds at 60 psi depending on the tire.
Those figures are load-rating references, not blanket instructions to inflate every tire to its maximum value. A small MG sports car often rides and handles best at pressures tailored to the vehicle's weight, distribution, and intended use, not at the tire's maximum rated pressure. Use the owner's manual as the baseline, then confirm that the selected tire's operating range and construction style are being respected for that exact application.
What should I check before taking a 1966 MG on a longer drive?
Before a longer drive in a 1966 MG, inspect all four tires and the spare for cracking, tread damage, bulges, punctures, and proper inflation. Check valve stems, and pay extra attention to older bias-ply tires or any setup that may involve tube-type service because age-related issues often show up there first. Wheel fastener security, brake condition, steering play, fluid levels, and lighting should be part of the same pre-trip routine on any mid-1960s MG.
Longer drives place steady heat and load into the tire, so small problems that go unnoticed around town become more serious once the car is at speed for an extended period. A careful pre-drive inspection is especially worthwhile on cars that sit between uses, since time in storage can change pressures and expose cracks without adding any miles. The goal is to catch age, setup, and maintenance issues before they become roadside problems.
