1968 Morgan Tire Fitment Guide

1968 Morgan vehicles use four tire sizes across two models: 155R15, 560-15, 165R15, and 590-15. The 4-4 Series uses 155R15 and 560-15, while the Plus 4 uses those two shared sizes plus 165R15 and 590-15. All four sizes mount on 15-inch rims, but the approved rim-width range changes by size. 155R15 fits 4.00 to 5.50-inch rims where specified, 560-15 fits 4.5 to 5.50-inch rims, 165R15 fits 4.50 to 6.00-inch rims, and 590-15 fits 4.00 to 4.50-inch rims where specified.

That means year and make alone are not enough for every 1968 Morgan. If you own a Plus 4, you need to confirm whether the car is running one of the shared sizes or one of the Plus 4-specific sizes before choosing a tire. If you own a 4-4 Series, the decision is narrower and usually centers on whether you want the radial 155R15 or the bias-ply 560-15.

On a 1968 Morgan, 560-15 is a numeric bias-ply tire size. The 5.60 is the nominal section-width code used in older sizing systems, and the 15 identifies the wheel diameter in inches. It is a classic-era format rather than a modern metric radial size, and on 1968 Morgan applications it appears on both the 4-4 Series and the Plus 4.

Buyers usually see 560-15 when they want a more period-authentic appearance and classic bias-ply construction. Sidewall appearance can vary within this size, with both narrow whitewall and wide whitewall options available. Before ordering, compare the look you want with the car's restoration theme and verify the wheel width against the tire's approved range.

On a 1968 Morgan, 155R15 is a radial tire size in an early metric format. The 155 is the section width in millimeters, the R indicates radial construction, and the 15 is the rim diameter in inches. Because no aspect ratio is printed, this size conventionally falls into the 80-series family. Both the 4-4 Series and Plus 4 can use 155R15.

That makes 155R15 one of the easiest cross-model choices within the 1968 Morgan range. It is offered in blackwall form, but tube status and speed rating differ by product, so one 155R15 should not automatically be treated as identical to another. Checking the full sidewall marking is especially important if you are matching existing tires or preserving a particular driving feel.

No, not all 1968 Morgan models use the same tire size. The 4-4 Series shares 155R15 and 560-15 with the Plus 4, but the Plus 4 also uses 165R15 and 590-15. All of them are 15-inch sizes, yet the tire width, construction choices, and wheel-width compatibility differ enough that model identification still matters.

For a buyer, the practical takeaway is simple: a 1968 Morgan Plus 4 needs more checking than a 4-4 Series. If the car has already been restored or driven for years on one size, use that as a clue, then confirm the wheel and tire combination on the car. Going by year and make alone can steer a Plus 4 owner toward a shared size when the car may actually be set up for one of the model-specific options.

For a 1968 Morgan 4-4 Series or Plus 4 that accepts either shared size, the difference is mainly construction and character rather than rim diameter. The 155R15 is a radial, while the 560-15 is a bias-ply. Both are 15-inch fitments, but the radial choice leans toward a later-period roadgoing feel, while the bias-ply choice stays closer to the traditional tire construction these cars would have known in period.

Choose 560-15 if your priority is a more authentic vintage presentation and classic bias-ply behavior. Choose 155R15 if you want a metric radial alternative in a narrow profile and your wheel width matches the tire's approved range. The best answer depends on how the car will be used, whether originality is important to you, and whether the rest of the car is set up around a bias-ply or radial tire.

1968 Morgan tire choices cover blackwall, narrow whitewall, and wide whitewall styles, but the exact style depends on size. The 155R15 radial options are blackwall, the 560-15 bias-ply options come in narrow and wide whitewall form, the 165R15 radial options include blackwall, narrow whitewall, and wide whitewall, and the 590-15 bias-ply options include blackwall and wide whitewall.

For many Morgan owners, sidewall style is as important as the size itself because it changes the car's visual era and personality. A blackwall usually suits a sporting British roadster presentation, while whitewall choices create a more stylized or export-market look. Match the sidewall to your restoration goal rather than treating every option as equally authentic for every version of a 1968 Morgan.

1968 Morgan sizes are available from Firestone, Michelin, US Royal, Coker Classic, American Classic, BFGoodrich, and Avon. The 155R15 range comes from Firestone and Michelin, 560-15 comes from Firestone and US Royal, 165R15 comes from Coker Classic, American Classic, Firestone, and BFGoodrich, and 590-15 comes from BFGoodrich and Avon. That gives Morgan owners a mix of American and European-leaning choices across both radial and bias-ply constructions.

Brand selection matters most after the correct size has been settled. Once you know your model and tire size, compare the sidewall treatment, speed symbol where present, and tube or tubeless marking rather than choosing by brand name alone. On a niche British sports car like a Morgan, the right combination of construction, appearance, and wheel compatibility usually matters more than any single badge on the sidewall.

Rim-width requirements for 1968 Morgan tires vary by size. 155R15 fits 4.00 to 5.50-inch rims where specified, 560-15 fits 4.5 to 5.50-inch rims, 165R15 fits 4.50 to 6.00-inch rims, and 590-15 fits 4.00 to 4.50-inch rims where specified. Every size mounts on a 15-inch rim, but width compatibility is not interchangeable across the whole range.

That matters most on the Plus 4, where both narrower and wider 15-inch sizes appear. A tire can share the same rim diameter as another option and still be wrong for the wheel because the width range is different. Before mounting a new set, measure the wheel or verify it against the actual wheel specification so the tire's approved range matches the rim already on the car.

Inner-tube requirements on 1968 Morgan tires depend on the exact product and size. Within 155R15, tube status varies by product: some versions are tubeless, while others are marked tube type. The 560-15 products shown here do not carry a TT or TL marker in the size field, and the 165R15 products do not show a tube marker either. In 590-15, the Avon 590H15 carries no TL marker and should be checked against the tire's own sidewall marking and wheel design before use.

The key point is not to assume all tires in the same nominal size use the same setup. Wire wheels, older rim profiles, and period-correct restorations can affect whether a tube is appropriate even when a modern tire exists in tubeless form. For a 1968 Morgan, confirm both the tire marking and the wheel type before final assembly so the casing, valve arrangement, and wheel are all working together properly.

Original 1968 Morgan wheels can often accommodate more than one tire size because every size used across the 4-4 Series and Plus 4 is a 15-inch fitment. That shared rim diameter makes cross-size compatibility possible at the diameter level. The limiting factor is wheel width, since 590-15, 155R15, 560-15, and 165R15 do not all share the same approved width range.

In practice, that means some original wheels may work with multiple Morgan sizes, while others will not be suitable for the full range. A Plus 4 owner moving between 590-15 and 165R15, for example, should verify wheel width carefully rather than assuming all 15-inch Morgan wheels are equivalent. Diameter gets you into the conversation; width is what confirms whether the wheel and tire truly belong together.

A 1968 Morgan stores best in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, welders, and other ozone sources that can age rubber prematurely. Keep the tires clean, maintain inflation, and move the car periodically if it will sit for long stretches. Bias-ply tires such as 560-15 and 590-15 are more prone to flat-spotting during static storage, while radials like 155R15 and 165R15 generally recover more quickly after a period of rest.

If the car will be parked for an extended season, many collectors either roll it occasionally or support it in a way that reduces long-term stress on one contact patch. That is especially worthwhile on a light British sports car that may spend long periods off the road. Good storage habits protect both the tires and the way the Morgan feels when it first goes back into service.

Tires on a 1968 Morgan usually age out before they wear out, because collector cars often cover limited mileage. A useful rule is to evaluate them closely once they reach five to seven years of age and to consider replacement as they approach ten years, regardless of tread depth. The DOT date code, sidewall condition, and the way the tire holds pressure are more meaningful than miles alone on a low-use Morgan.

That guideline matters whether your car runs radial or bias-ply tires. Even a Morgan driven only on fair-weather weekends can develop age-related cracking, hardening, or internal deterioration over time. If you recently acquired the car and do not know the age of the tires, checking the date code should be one of the first maintenance steps before relying on them for regular road use.

Tires on a 1968 Morgan should be inspected before every drive and again before any extended outing. Look for sidewall cracking, cuts, bulges, uneven wear, embedded debris, and pressure loss. On any setup using tube-type tires or tube-compatible assemblies, include the valve stems and the wheel's sealing condition in the inspection, since a sound casing alone does not guarantee the whole assembly is ready for the road.

Frequent inspection is especially important on an older sports car because the tires are only one part of a much older mechanical system. A quick walkaround catches problems early and also helps you notice alignment or suspension issues that show up as unusual tread wear. For a 1968 Morgan, this simple habit does more for peace of mind than waiting for a problem to announce itself once the car is already moving.

A 1968 Morgan 4-4 Series would have been associated first with bias-ply tire practice in period, even though radial options are available today in the shared 155R15 size. On this year and make, the 4-4 Series uses 560-15 as its bias-ply choice and 155R15 as its radial alternative. That makes 560-15 the more era-consistent starting point for an owner pursuing a factory-style look and feel.

Original-equipment details could still vary by market, dealer practice, or later wheel changes over the life of the car, so a serious authenticity-focused restoration should compare the car against period photos, handbooks, and marque-club knowledge. If the goal is judged originality, size, construction, and sidewall treatment all matter. The right answer for one 1968 Morgan 4-4 Series may not be identical to another car that has a different restoration history.

Correct tire fitment absolutely matters when a 1968 Morgan is judged for authenticity. Judges and marque specialists commonly look at the tire's size, construction type, and sidewall appearance because those details strongly affect the car's stance and period character. A radial in place of a bias-ply, or a whitewall style that does not suit the way the car would have appeared in period, can stand out immediately on a traditionally styled Morgan.

That does not mean every show car must wear the same tire, but it does mean the choice should be intentional. If you are building a concours-oriented Morgan, use period photos, club guidance, and event rules to decide whether a blackwall, narrow whitewall, or wide whitewall presentation makes sense. The more exacting the judging standard, the more important those tire details become.

For a 1968 Morgan using 155R15, Michelin XAS and Michelin XAS-FF are both H-rated 155HR15 tires with an 82 load index and a 15-inch rim diameter. Each fits a 4.00 to 5.50-inch rim range and both appear in blackwall form. The important distinction here is tube status: the XAS is marked TT, while the XAS-FF is marked TL.

That difference matters when you are matching the tire to the wheel and to the way the car will be assembled. If your Morgan has a wheel setup that benefits from a tube-type tire, the XAS may be the more natural fit. If your wheel and restoration approach support a tubeless-marked option, the XAS-FF offers the same basic size and speed category with a different assembly path.

1968 Morgan tires can be suitable for highway driving when the tires are in good condition, correctly matched to the wheel, and used within their construction and speed limits. Among the sizes here, 155R15 includes T-rated products to 118 mph and H-rated products to 130 mph, while 590-15 includes H-rated versions to 130 mph. Other products in these sizes do not always carry a speed symbol in the visible size marking, so the exact tire should be checked individually.

On a 1968 Morgan, overall roadworthiness depends on more than the tire alone. Brakes, steering, suspension condition, alignment, and the realities of a lightweight vintage sports car usually matter at least as much as the tire's nominal speed capability at normal U.S. highway speeds. For regular road use, choose the correct size first, then confirm the tire's speed symbol and the car's mechanical readiness before setting off.

Inflation pressure for a 1968 Morgan should start with the factory recommendation for the model and then be checked against the tire manufacturer's maximum load-and-pressure figures for the exact tire you are using. In these sizes, 155R15 appears with a maximum load of 1045 pounds at 44 psi on one product, 560-15 appears at 970 pounds at 32 psi, 165R15 appears at 1168 pounds at 35 psi and 1170 pounds at 36 psi, and 590-15 appears at 1050 pounds at 32 psi or 1,018 pounds on one Avon version.

Those figures are not blanket operating pressures for every 1968 Morgan tire; they are the tire's rated maximum figures for the products where they appear. Actual running pressure should reflect the car, the axle load, and the manufacturer's guidance for that specific tire. Do not transfer a pressure from one Morgan size to another simply because both fit a 15-inch wheel.

Before a longer drive in a 1968 Morgan, inspect each tire for sidewall cracking, tread separation, cuts, bulges, uneven wear, and proper inflation. Check the valve stems, and if the car uses tube-type assemblies, make sure the stems sit correctly and show no damage. The spare deserves the same attention, because a decades-old spare can be unusable even when it still holds air.

A longer trip also calls for a broader mechanical review because a Morgan's age makes the rest of the chassis just as relevant as the tires. Wheel fasteners, steering response, brake feel, fluid levels, and suspension condition all deserve a look before the car leaves home. The tire check is the first layer of confidence, not the only one, and that is especially true on a hand-built vintage sports car.