1968 Mercury Tire Fitment Guide

1968 Mercury vehicles use seven sizes across four model groups: 8.25-15 and 855-15 for full-size Mercury applications, 855-15 for Mercury wagons, E70-14, F70-14, and FR70-14 for Cougar, and 735-14, 775-14, and F70-14 for Montego. The 15-inch sizes are separate from the 14-inch sizes, so year and make alone are not enough to choose correctly. Where rim-width information is available, 855-15 fits 6.00 to 6.50-inch rims, E70-14 and F70-14 fit 6.00 to 7.00-inch rims, FR70-14 uses a 6-inch rim, 735-14 fits 5.00 to 5.50-inch rims, and 775-14 spans 5.00 to 6.00 inches depending on the tire.

The practical takeaway is to identify your Mercury by model before you choose by style. A Cougar owner deciding between E70-14, F70-14, and FR70-14 is making a different decision than a wagon owner choosing 855-15, and a Montego owner has to know whether the car belongs in the narrower 735-14 range, the wider 775-14 range, or the sporty F70-14 fitment. Once the model is confirmed, check the wheel diameter and rim width against the actual wheel on the car.

On a 1968 Mercury, E70-14 is an alphanumeric bias-ply size. The E70 portion identifies the tire's size class in the late-1960s alphanumeric system, and the 14 means it mounts on a 14-inch wheel. In this Mercury range, E70-14 appears on the Cougar and is available in muscle-era sidewall treatments such as pin white stripe, redline, and raised white letters.

That code matters because it places the tire squarely in the styling language of a 1968 sporty Mercury. If your Cougar restoration aims for original visual character, the alphanumeric bias-ply format is part of the look, not just the fit. It also helps separate the Cougar's sporty tire choices from the full-size Mercury 15-inch sizes and from Montego's numeric 14-inch fitments, which belong to a different part of the Mercury lineup.

No, 1968 Mercury models do not share one universal tire size. Full-size Mercury applications use 8.25-15 or 855-15, wagons use 855-15, Cougar uses E70-14, F70-14, or FR70-14, and Montego uses 735-14, 775-14, or F70-14. Only F70-14 is shared across more than one model group here, and it belongs to both Cougar and Montego.

That variation means the correct starting point is the model name on the car, not just the Mercury badge. A buyer comparing a Cougar to a Montego may see the same 14-inch wheel diameter in some cases, yet the proper size family and sidewall style choices still differ. If the car has changed hands several times or has aftermarket wheels, verify the actual wheel diameter before choosing a tire by appearance alone.

For a 1968 Mercury, that question mainly applies to the Cougar, where F70-14 is a bias-ply size and FR70-14 is a radial size with a vintage-style look. F70-14 keeps the late-1960s bias-ply construction that suits factory-style presentation, while FR70-14 brings radial construction on the same 14-inch wheel diameter. Both carry a 1500-pound load rating at 32 psi in the products available here, but they serve different priorities.

Choose F70-14 if your goal is a more era-authentic construction and sidewall presentation on a Cougar judged or restored around original appearance. Choose FR70-14 if you want a radial option while staying close to a period visual theme through raised white lettering. The important part is not assuming they are interchangeable by appearance alone; confirm that your Cougar's wheel width and your restoration goal both line up with the tire you select.

1968 Mercury tires cover a wide span of sidewall styles depending on size. Full-size 855-15 tires are available as Narrow Whitewalls, E70-14 and F70-14 bring pin white stripe, redline, and raised white letter choices, FR70-14 appears as raised white letter, 735-14 comes in Blackwall or Narrow Whitewall, and 775-14 adds Blackwall, Narrow Whitewall, and Redline options. That range reflects Mercury's broad market position, from upscale family cars to sporty intermediates and pony cars.

For a late-1960s Mercury, the sidewall can change the car's personality almost as much as the wheel itself. Narrow whitewalls tend to fit more conservative full-size and mid-size restorations, while redlines and raised white letters are more at home on performance-flavored Cougar and Montego builds. If authenticity matters, match the sidewall style to the model's character and the way the car would have been equipped, then verify with period photos or marque references.

1968 Mercury tires are available from BFGoodrich, Firestone, Goodyear, and US Royal, depending on size. BFGoodrich covers 855-15, 735-14, and 775-14; Firestone covers E70-14, F70-14, and 775-14; Goodyear covers E70-14, F70-14, and FR70-14; and US Royal appears in 775-14. Brand choice is tied closely to size and sidewall style rather than being uniform across the whole Mercury line.

That matters because many buyers begin with a brand preference when the smarter first move is choosing the correct size and construction. Once the proper size is set, brand selection lets you fine-tune the look, whether that means a classic narrow whitewall on a full-size Mercury or a Wide Oval or Custom Wide Tread presentation on a sporty 14-inch application. Keep the car's model identity and intended appearance ahead of badge loyalty.

Rim width depends on the size. 855-15 fits 6.00 to 6.50-inch rims, E70-14 and F70-14 fit 6.00 to 7.00-inch rims, FR70-14 uses a 6-inch rim, 735-14 fits 5.00 to 5.50-inch rims, and 775-14 spans 5.00 to 6.00 inches depending on the tire. Those ranges are important because Mercury used both 14-inch and 15-inch applications in 1968, and even among 14-inch sizes the wheel width needs are not identical.

The best practice is to measure or verify the wheel already on the car before choosing between close-looking sizes. A Montego owner deciding between 735-14 and 775-14, for example, should confirm wheel width rather than assuming either size will sit correctly. If the car wears replacement wheels, avoid relying on what the previous owner mounted; match the tire to the actual wheel dimensions and the intended look of the car.

The available 1968 Mercury products do not show tube-type or tubeless markers in the size notation, so tube decisions should be made by the specific tire and wheel combination rather than by size name alone. Bias-ply and radial-style tires can both end up being used with or without tubes depending on wheel design, wheel condition, and the exact tire's construction. That is especially relevant on original 1960s wheels that may have seen decades of service.

The smart move is to inspect the wheel first and follow the exact sidewall marking and manufacturer guidance for the tire you choose. Wheels with pitting, riveted construction, or other age-related issues may change whether a tube is advisable. If you are preserving original Mercury wheels, have them checked for sealing condition and valve-stem integrity before the tires go on, rather than treating tube use as a one-answer rule for every 1968 Mercury.

A 1968 Mercury should be stored in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, and other ozone-producing equipment. Keep the tires clean, maintain proper inflation, and move the car periodically so one section of the casing does not carry the load for months at a time. Bias-ply tires are more prone to flat-spotting during long static storage, while any vintage-style sidewall can suffer from ozone and UV exposure.

If the car will sit through a long season, rolling it occasionally or supporting it in a way that reduces prolonged stress can help preserve the tire shape. This matters on a collector Mercury because many cars cover limited mileage yet spend long periods parked. Good storage habits protect both appearance and ride quality, which is especially valuable if you are trying to keep a whitewall, redline, or raised white letter tire looking fresh.

Tire life on a 1968 Mercury is usually judged more by age than mileage. A collector car tire should be evaluated closely once it reaches about five to seven years of service, and replacement deserves serious consideration as it approaches the ten-year mark, even if the tread still looks deep. The DOT date code on the sidewall is the best way to determine age on a modern reproduction or radial-style tire.

That age-based approach matters because many Mercurys live easy lives with low annual mileage, which can make old tires look healthier than they really are. Sidewall cracking, hardening, persistent vibration, or pressure loss are stronger warning signs than odometer readings. If the car is driven only to shows or weekend events, age still counts, and older tires should not be kept in service simply because they have attractive tread left.

Tires on a 1968 Mercury should be inspected before every drive and again before any longer trip. Look for sidewall cracking, weather checking, cuts, bulges, uneven wear, embedded debris, and pressure loss. The inspection should also include valve stems and the spare, because a collector car often depends on components that may be far older than their appearance suggests.

Frequent checks are especially important on cars that alternate between long storage periods and occasional road use. A Mercury that feels fine around town can reveal age-related issues only when it is loaded with passengers or driven at sustained speeds. Building a quick pre-drive inspection into your routine is one of the simplest ways to protect the car, the wheels, and the trip itself.

A 1968 Mercury Cougar would have been associated primarily with bias-ply tire construction in period, and the size range here reflects that with E70-14 and F70-14 as its core vintage-style fitments. FR70-14 brings a radial option to the same model, but radial fitments were not the mainstream factory norm for American sporty cars in 1968. Original-equipment branding could vary by market and equipment package, so size, construction, and sidewall style are safer guides than assuming one universal brand.

For an accurate restoration, start with the Cougar's exact model identity and period appearance rather than jumping straight to a favorite brand. An owner aiming for showroom-era presentation will usually focus on the correct 14-inch bias-ply family and an appropriate sidewall treatment such as redline, pin stripe, or raised white letters. If your car will be judged, compare against factory literature and consult Cougar specialists or marque clubs for trim-specific confirmation.

Yes, correct tire fitment matters on a 1968 Mercury because judges and knowledgeable enthusiasts often notice size, construction, and sidewall style immediately. A full-size Mercury on the wrong 14-inch muscle-car tire, or a Cougar wearing a modern-looking sidewall that does not match the car's era, can look out of place even if the tire physically mounts. Construction can matter too, especially when a car is restored for authenticity rather than regular road use.

The key is matching the tire to the personality and class of the specific Mercury. Narrow whitewalls generally read differently than redlines or raised white letters, and a radial-style option may be viewed differently from a bias-ply on a car judged for originality. If the car is heading to marque-specific judging, use the event's standards and club knowledge as the final reference, because regional and class expectations can differ.

For a 1968 Mercury in E70-14 or F70-14, Firestone Wide Oval and Goodyear Custom Wide Tread sit in the same broad performance-era visual category but differ in sidewall presentation and weight. Firestone offers pin white stripe, redline, and raised white letter versions, while Goodyear appears here as raised white letter. In E70-14, Firestone weighs 22 to 23 pounds and Goodyear 24 pounds; in F70-14, Firestone weighs 24 pounds and Goodyear 25 pounds. Both share 6.00 to 7.00-inch rim compatibility and the same load ratings within each size.

That makes the choice more about the exact visual theme you want on the car than about major fitment differences. If a Cougar or Montego restoration needs a specific redline or pin-stripe look, Firestone opens more doors. If raised white letters are the goal, both brands support that muscle-era appearance, so the final decision can come down to brand loyalty, tread style preference, and how closely the tire's look matches the story you want the Mercury to tell.

1968 Mercury tires can be suitable for highway driving when they are the correct size, in sound condition, and used within the limits of their construction and any stated speed rating. The tires here do not show speed-letter markings in the size notation, so highway use should be approached with the understanding that bias-ply and vintage-style radial tires are different from modern high-speed touring tires. On a well-sorted classic Mercury, the condition of the car's brakes, steering, suspension, and alignment is often just as important as the tire itself.

The practical lesson is to think of the whole car, not just the rubber. A freshly mounted tire cannot compensate for worn steering linkage, weak shocks, or decades-old brake components, and those systems strongly shape confidence at road speed in a late-1960s car. If you plan to drive farther or faster than local show traffic, inspect the chassis first, set pressures carefully, and give the tire time to prove itself under normal driving before longer interstate trips.

The products here show maximum load figures at 32 psi for the sizes where load data appears: 855-15 at 1710 pounds, E70-14 at 1400 pounds, F70-14 and FR70-14 at 1500 pounds, 735-14 at 1360 pounds, and 775-14 at 1580 pounds where stated. Those figures are tire ratings, not blanket running-pressure instructions for every 1968 Mercury. Factory operating pressure should still be confirmed from the Mercury owner's literature or a marque reference for the exact model.

That distinction matters because a tire's maximum-rated pressure is not automatically the ideal inflation pressure on the car. Vehicle weight distribution, suspension tuning, and ride expectations all influence the final setting, and those factors differ between a full-size Mercury, a wagon, a Cougar, and a Montego. Start with the factory recommendation for your model, then make sure the tire's own load and pressure markings support that use without borrowing numbers from a different size.

Before a longer drive in a 1968 Mercury, inspect each tire for cracking, tread separation, bulges, cuts, punctures, and uneven wear, then verify inflation pressure when the tires are cold. Check the valve stems, lug nut tightness, and the spare's condition as well. Because these cars may run anything from narrow whitewall bias-ply tires to raised white letter performance-style tires, matching left-to-right condition and pressure is important for predictable road manners.

Treat the tires as one part of a broader pre-trip check that also includes brakes, fluid levels, belts, hoses, lights, and wheel bearings. A classic Mercury that sees limited annual mileage can still have age-related weaknesses, especially after sitting. Giving the tires and the rest of the car a thorough inspection before departure is far easier than dealing with a roadside failure in a vehicle that was built when service infrastructure and highway expectations were very different.