The 1968 MG 1100 came from the era when compact British sedans emphasized efficiency, tidy exterior dimensions, and light, responsive road manners over sheer size. That makes tire selection especially important, because the car’s character depends heavily on maintaining the right proportions on its 12-inch wheels. This model is associated with both a 5.50-12 bias-ply fitment and a 145R12 radial fitment, so the key decision is whether to preserve a more traditional construction or evaluate the radial option already tied to this car. For owners balancing originality, drivability, and appearance, construction choice matters just as much as size.
Which Tire Size Is Right for The 1968 MG 1100
The 1968 MG 1100 uses two primary tire sizes, and the difference is tied mainly to construction rather than wheel diameter, since both fit 12-inch rims. The first step is confirming whether the car is being kept with its traditional 5.50-12 bias-ply setup or fitted with the 145R12 radial size, because that choice affects both appearance and on-road feel.
145R12 is a Euro-metric radial size in which 145 identifies the nominal section width in millimeters, R indicates radial construction, and 12 is the rim diameter in inches. On a 1968 MG 1100, this size represents the radial fitment associated with the car’s compact 12-inch wheel package. Michelin offers this size in the Michelin MX series with a blackwall sidewall, giving buyers a traditional small-car radial presentation rather than a wide range of cosmetic treatments. It is a useful choice for owners who want a radial tire in the documented size for this model.
5.50-12 is a numeric bias-ply size in which 5.50 refers to the nominal section width in inches and 12 identifies the rim diameter. That sizing style is typical of period bias-ply tires and suits the late-1960s character of the MG 1100 particularly well when a more traditional construction is the goal. Bias-ply fitment also tends to matter to owners who want the car to retain a restoration-oriented stance and presentation on its original-style wheel diameter. Before selecting this size, it is worth confirming that the car still has the wheel and chassis setup intended for the bias-ply fitment.
Sub-model fitment is straightforward here, because the covered 1968 MG 1100 Sport Sedan is associated with the same two size paths already tied to the model. Checking the exact sub-model still helps confirm whether the car is being kept with its bias-ply setup or matched to the radial option.
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1968 MG 1100 Sport Sedan
The 1968 MG 1100 Sport Sedan is associated with both the 5.50-12 bias-ply size and the 145R12 radial size on 12-inch rims. That gives the owner a clear construction decision between a more traditional period-style presentation and the radial fitment already tied to this sub-model.
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 1968 MG 1100 Tires for Sale
Current product choices center on the 145R12 radial size, where Michelin offers the Michelin MX series in a blackwall configuration. That gives buyers a focused radial option to compare by construction, series, and wheel-width compatibility.
These FAQs for the 1968 MG 1100 focus on its two primary tire sizes, 12-inch rim fitment, bias-ply versus radial choice, available product selection, and the checks worth making before regular road use.
Tire Size & Fitment
What tire size fits a 1968 MG 1100?
The 1968 MG 1100 is associated with two primary tire sizes: 145R12 in radial construction and 5.50-12 in bias-ply construction. Both sizes use a 12-inch rim, so the main difference is not wheel diameter but the sizing system and tire construction tied to the car.
That means the real decision is whether the car should remain with a traditional bias-ply presentation or use the radial fitment already associated with this model. Checking the actual wheels on the car, along with its current tire type and intended use, helps narrow the choice before selecting a specific tire.
What size rim does a 1968 MG 1100 use?
The 1968 MG 1100 uses a 12-inch rim diameter with both of its associated tire sizes, 145R12 and 5.50-12. In practical terms, that keeps rim diameter simple, because the fitment question centers more on tire construction and exact wheel width than on changing wheel diameter.
A 12-inch wheel still needs to be checked carefully before buying tires, especially on an older small British sedan. Verifying the actual wheel width, condition, and any past wheel changes matters, since age, replacement wheels, or previous modifications can affect how well either the bias-ply or radial size suits the car.
Does the 1968 MG 1100 Sport Sedan use the same tire size?
Yes. The 1968 MG 1100 Sport Sedan is associated with the same two size paths as the model overall: 145R12 radial and 5.50-12 bias-ply. That keeps fitment straightforward at the sub-model level, since the Sport Sedan does not introduce a separate rim diameter or an additional primary size.
Even with shared sub-model fitment, the car should still be checked as it sits today. A Sport Sedan that has been converted to different wheels or kept on one construction type for years may call for a closer look at wheel width, tire clearance, and the owner’s restoration or driving priorities before making a selection.
Bias-Ply & Radial Options
Is 5.50-12 a bias-ply or radial tire for the 1968 MG 1100?
On the 1968 MG 1100, 5.50-12 is a bias-ply tire size. It uses the older numeric sizing convention common on many period vehicles, where the first number represents nominal section width in inches and the final number identifies the 12-inch rim diameter.
That matters because choosing 5.50-12 is partly a construction decision, not just a size decision. Buyers usually consider it when a more traditional look and period-style setup are important, while owners seeking the radial fitment associated with this model would look instead at 145R12 after confirming wheel condition and overall compatibility.
Should I use bias-ply or radial tires on a 1968 MG 1100?
Either construction can be relevant to a 1968 MG 1100, since this model is associated with both 5.50-12 bias-ply and 145R12 radial fitment. The best direction depends on the car’s current wheel setup, how closely the owner wants to stay with a traditional presentation, and how the car is expected to be used.
Bias-ply tires are often chosen for a more period-style appearance, while radial tires appeal to owners who want the documented radial size already tied to this model. Matching the tire to the actual wheels on the car is important, and any shift in construction should be checked for wheel-width suitability, clearance, and overall vehicle condition.
What should I check before converting my 1968 MG 1100 from bias-ply to radial tires?
A move from 5.50-12 bias-ply to 145R12 radial on a 1968 MG 1100 starts with confirming the wheel diameter and wheel width already on the car. The wheel condition, tire clearance, and the car’s overall setup should also be reviewed before assuming that a different construction is automatically suitable.
Construction changes can affect how the car feels and how the tire sits within the wheel opening, even when rim diameter remains the same. Older suspension parts, replacement wheels, and prior modifications deserve attention first, especially on a compact car where small changes in width or clearance can make a noticeable difference.
Choosing the Right Tire
What should I consider when choosing a tire for a 1968 MG 1100?
Start with the primary fitment question: whether the car should use the 5.50-12 bias-ply size or the 145R12 radial size. From there, the important details are wheel diameter, wheel width, construction type, and whether the goal is a restoration-oriented presentation or a radial setup already associated with this model.
Product choice becomes easier once that first decision is made. For the available 145R12 radial option, buyers can compare details such as the tire series, blackwall appearance, and wheel-width compatibility, while owners leaning toward bias-ply fitment should make sure the car’s wheels and current setup still suit that traditional size and construction.
What sidewall styles are available for 1968 MG 1100 tires?
The currently available product choice in 145R12 is offered as a blackwall. That keeps the visual presentation simple and in line with the compact, understated character many owners want from a small late-1960s British sedan, especially when the goal is a clean radial fitment rather than a decorative sidewall treatment.
Sidewall style still matters because it affects the car’s overall look as much as the wheel itself. A buyer choosing among available MG 1100 tires should consider whether a plain blackwall better matches the car’s intended appearance, and then confirm that the construction and size choice also align with the way the vehicle will be driven.
What brands offer tires for the 1968 MG 1100?
Michelin offers a tire for the 1968 MG 1100 in the 145R12 radial size. That product is the Michelin MX series, which gives buyers a recognizable small-car radial option in the documented 12-inch fitment associated with this MG.
Brand choice is only one part of the decision on a car like this. The bigger question is whether the owner wants the radial size already tied to the model or prefers to keep the traditional 5.50-12 bias-ply route, then match that decision to wheel compatibility, appearance goals, and the car’s actual setup.
Restoration & Appearance
Which tire should I choose for a period-style 1968 MG 1100?
For a period-style 1968 MG 1100, the 5.50-12 bias-ply size is the natural starting point because it preserves the vintage numeric sizing format and traditional construction associated with the car. That approach often appeals to owners who want the vehicle to look and sit in a manner closer to its late-1960s character.
Appearance goals should still be balanced against how the car will actually be used. A radial 145R12 option is also associated with this model, so the right choice depends on whether the priority is historical presentation, regular road use, or a blend of the two with careful attention to wheel and chassis compatibility.
How does tire construction affect the appearance of a restored 1968 MG 1100?
Tire construction changes more than road feel on a restored 1968 MG 1100; it also changes the visual character of the car. A 5.50-12 bias-ply generally supports a more traditional small-sedan presentation, while a 145R12 radial brings the look of a later-style metric tire to the same 12-inch wheel diameter.
That visual difference matters on a compact British car where the tire sidewall is very noticeable in relation to the body and wheel opening. Owners pursuing exact originality should compare their choice against marque references or restoration records, while those aiming for a period-style result can focus on the overall stance and tire profile.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1968 MG 1100?
Yes. Even though the 1968 MG 1100 is associated with 12-inch fitment in both 145R12 and 5.50-12, aftermarket wheels, suspension changes, brake updates, or body alterations can affect what actually works on the car. Small cars tend to show clearance changes quickly, so minor modifications can matter more than expected.
A buyer should look at the car as it sits rather than relying only on model-year fitment. Wheel width, steering clearance, tire-to-fender space, and the condition of suspension components are worth checking first, especially if the vehicle has been restored, altered over time, or converted from one tire construction to another.
What should I inspect before driving a 1968 MG 1100 on new tires?
Before road use, inspect the wheels for damage or corrosion, confirm that the tires match the intended size and construction, and make sure inflation is set correctly for the tire being used. It is also wise to check for rubbing at full steering lock and look over suspension and steering components on a car of this age.
A short initial drive can reveal issues that are easy to miss while the car is parked. Listen for contact noises, watch for pulling or vibration, and recheck pressure after the first outing. On an older MG, roadworthiness depends not only on fresh tires but also on the surrounding wheel, brake, and suspension condition.
How should tires on a collector 1968 MG 1100 be maintained?
Tires on a collector 1968 MG 1100 should be inspected regularly for cracking, bulges, cuts, uneven wear, and gradual air loss, especially if the car spends long periods parked. Pressure checks matter even on low-mileage vehicles, because age and storage conditions can affect a tire long before tread wear becomes obvious.
Storage habits have a real effect on tire life. Keeping the car away from prolonged sunlight, excess heat, moisture, and ozone sources helps preserve both bias-ply and radial tires, and occasional movement prevents flat-spotting from becoming a bigger issue. Any tire showing age-related deterioration deserves close evaluation before further road use.
