In 1968, Jaguar offered a distinctly British mix of compact sporting sedans, refined saloons, and the still-iconic XKE, giving buyers very different cars under one storied badge. The 340 carried traditional compact Jaguar character, the 420 leaned further into luxury and long-distance comfort, and the XKE remained one of the era’s defining performance cars. Tire choice across 1968 Jaguar models is not one-size-fits-all: the 340 and XKE share 15-inch radial and bias-ply options, while the 420 also adds its own 14-inch radial and bias-ply sizes. Before choosing a tire, confirm your exact model first, then decide whether originality or modern road manners matters more for how you use the car.
Which Tire Size Is Right for Your 1968 Jaguar
Four tire sizes are used across 1968 Jaguar vehicles, and they vary by model rather than carrying across the full range. The real decision starts with confirming whether your car uses a 14-inch or 15-inch wheel, then choosing between bias-ply character and radial road manners where both constructions exist. Understanding that difference before choosing a product saves time and helps you match the tire to the right Jaguar model.
Year(s): 1968|Fit(s): 340, 420, XKE|Construction: Radial|Rim: 15 in
185R15 is a metric radial size with a 185-millimeter nominal section width and a 15-inch rim diameter; in this older Euro-metric format, the aspect ratio is conventionally about an 80-series profile. It is available from Coker Classic and Michelin in redline, narrow whitewall, and blackwall styles, and tubeless construction appears across the products with speed ratings that vary by product, including H at 130 mph and V at 149 mph on Michelin versions. This is one of the shared 15-inch sizes used across the 1968 Jaguar 340, 420, and XKE. It suits owners who want a radial tire in an era-appropriate size with a choice of appearance details.
Year(s): 1968|Fit(s): 340, 420, XKE|Construction: Bias Ply|Rim: 15 in
640-15 is a numeric bias-ply size in which 6.40 represents the nominal section width and 15 is the wheel diameter in inches. It is available from BFGoodrich and Firestone with wide whitewall and narrow whitewall treatments, and load capacities among these products range from 970 pounds at 32 psi to 1190 pounds at 32 psi. This is the shared bias-ply 15-inch choice for the 1968 Jaguar 340, 420, and XKE rather than a size unique to one model. It is the natural fit for owners pursuing a more period-authentic bias-ply look and feel.
Year(s): 1968|Fit(s): 420|Construction: Radial|Rim: 14 in
205R14 is a metric radial size with a 205-millimeter nominal section width and a 14-inch rim diameter, following the older Euro-metric convention that typically implies an 80-series profile. Michelin offers this size in blackwall form, and the available version is a tubeless V-rated radial with a 149 mph speed ceiling. This size is specific to the 1968 Jaguar 420 and is not used across the rest of the Jaguar range for the year. It makes sense for a 420 owner who wants the model-specific 14-inch radial option rather than one of the shared 15-inch sizes.
Year(s): 1968|Fit(s): 420|Construction: Bias Ply|Rim: 14 in
775-14 is a numeric bias-ply size where 7.75 denotes the nominal section width and 14 identifies the wheel diameter in inches. It is available from US Royal, BFGoodrich, and Firestone in narrow whitewall and redline styles, with load figures reaching 1580 pounds at 32 psi on several versions. This size is specific to the 1968 Jaguar 420 and does not carry over to the 340 or XKE. It is the 420’s model-specific bias-ply choice for owners who want a distinctly period presentation on the 14-inch wheel.
Three Jaguar models are covered for 1968. Tire size does vary by model, so year and make alone are not enough here: the 340 and XKE share 15-inch sizes, while the 420 can use those same 15-inch options or its own 14-inch sizes depending on wheel setup. Select your model below to narrow the fitment history and see the tires that match that specific Jaguar.
1968 Jaguar 340
The 1968 Jaguar 340 was the final evolution of Jaguar’s compact Mark 2-based sporting sedan, combining traditional Jaguar wood-and-leather character with a smaller, more agile saloon format. Its tire choices mount on 15-inch wheels, giving owners a straightforward decision between a bias-ply presentation and a radial alternative in the same rim diameter.
The 1968 Jaguar 420 was a more upscale compact saloon, blending traditional Jaguar refinement with a more modern late-1960s look and a stronger emphasis on comfort and touring. It is the most size-diverse model in the 1968 Jaguar range, with both 14-inch and 15-inch fitments appearing depending on wheel choice and setup.
The 1968 Jaguar XKE remained one of the defining sports cars of its era, known for its long-hood proportions, independent suspension, and unmistakable Jaguar presence. Its fitments mount on 15-inch wheels, leaving the main decision centered on whether the car is being kept closer to period bias-ply character or equipped with a radial in the same wheel diameter.
Sixteen products are available across four tire sizes for 1968 Jaguar vehicles. 185R15 includes 4 radial choices from Coker Classic and Michelin in redline, narrow whitewall, and blackwall styles; 640-15 includes 4 bias-ply choices from BFGoodrich and Firestone in wide and narrow whitewall; 205R14 includes 1 radial blackwall from Michelin; 775-14 includes 4 bias-ply choices from US Royal, BFGoodrich, and Firestone in narrow whitewall and redline styles. Confirm your model, wheel diameter, and construction preference before selecting.
These FAQs sort out the 14-inch versus 15-inch fitments across the 1968 Jaguar range, the bias-ply versus radial decision, available sidewall styles, and the practical checks that matter when a collector Jaguar sees occasional road use.
Size Basics & Fitment
What tire sizes fit 1968 Jaguar vehicles?
1968 Jaguar vehicles use four sizes overall: 185R15, 640-15, 205R14, and 775-14. The Jaguar 340 uses 185R15 and 640-15, the Jaguar XKE uses 185R15 and 640-15, and the Jaguar 420 uses all four sizes, with 205R14 and 775-14 as 14-inch options and 185R15 and 640-15 as 15-inch options. Rim width ranges vary by size and product: 185R15 appears from 4.5 to 6.5 inches, 640-15 from 4.0 to 5.0 inches, 205R14 from 5.5 to 7.5 inches, and 775-14 from 5.0 to 6.0 inches where specified.
That means a 1968 Jaguar owner should identify the model first and then confirm whether the car is on 14-inch or 15-inch wheels before narrowing tire choices. The 340 and XKE are simpler because both stay within the 15-inch family, while the 420 needs extra attention because both wheel diameters appear under the same year and model name.
What does 640-15 mean on a 1968 Jaguar tire?
On a 1968 Jaguar, 640-15 is a traditional numeric bias-ply size. The 6.40 figure refers to the nominal section width in inches, while the 15 identifies the wheel diameter in inches. For 1968 Jaguar applications, this size appears on the 340, 420, and XKE, all as a bias-ply choice rather than a radial format.
A 640-15 matters most to an owner who wants a period-correct appearance and the driving character associated with vintage bias-ply construction. It is not just a number on the sidewall; it also points you toward narrower wheel ranges than the radial alternatives, so wheel width confirmation is worth doing before choosing among the available whitewall versions.
Do all 1968 Jaguar models use the same tire size?
No. The 1968 Jaguar 340 and 1968 Jaguar XKE share the same two 15-inch sizes, 185R15 and 640-15, but the 1968 Jaguar 420 adds its own 14-inch sizes, 205R14 and 775-14. That makes the 420 the outlier in the range, since it can appear with either the shared 15-inch fitments or with model-specific 14-inch tires.
For a buyer, that means year and make are only the starting point on a 1968 Jaguar page. If you own a 420, confirm the wheel diameter already on the car rather than assuming it matches the 340 or XKE. If you own a 340 or XKE, the decision is usually simpler and centers on choosing between the 15-inch radial and 15-inch bias-ply options.
Buying the Right Tire
Should I choose the 185R15 or the 640-15 for my 1968 Jaguar?
For a 1968 Jaguar 340 or 1968 Jaguar XKE, and for a 1968 Jaguar 420 running 15-inch wheels, the choice between 185R15 and 640-15 is primarily a radial-versus-bias-ply decision. The 185R15 is a metric radial offered in blackwall, narrow whitewall, and redline versions, while the 640-15 is a numeric bias-ply offered in whitewall styles. Both fit the same 15-inch wheel diameter, but they represent two different construction types and visual eras.
Owners leaning toward authenticity in a period restoration often favor the 640-15 because it preserves a classic bias-ply look and feel. Owners who plan to drive more regularly often look to the 185R15 because it keeps an era-appropriate size while moving to radial construction. The right answer depends on how the car will be judged, displayed, and driven rather than on wheel diameter alone.
What sidewall styles are available for 1968 Jaguar tires?
1968 Jaguar tires are available in several sidewall styles depending on size. The 185R15 radial size comes in redline, narrow whitewall, and blackwall. The 640-15 bias-ply size comes in wide whitewall and narrow whitewall. The 205R14 radial appears in blackwall, while the 775-14 bias-ply size comes in narrow whitewall and redline.
Sidewall choice influences the car’s visual character as much as the construction choice does. On a 1968 Jaguar, blackwall and modest whitewall treatments usually feel more natural than very flashy sidewall designs, while redlines create a more personalized period look. Owners pursuing strict show authenticity should compare sidewall style to period photos, factory literature, and club guidance for their exact model and market.
What brands make tires for 1968 Jaguar vehicles?
1968 Jaguar tire coverage includes Coker Classic, Michelin, BFGoodrich, Firestone, and US Royal. In 185R15, the brands are Coker Classic and Michelin. In 640-15, the brands are BFGoodrich and Firestone. The 205R14 size is covered by Michelin, while 775-14 includes US Royal, BFGoodrich, and Firestone.
Those brand differences matter because they often track with both appearance and intended use. Michelin’s 14-inch and 15-inch radial offerings suit buyers seeking a European-style radial presentation, while the BFGoodrich, Firestone, and US Royal bias-ply selections bring period-correct sidewall treatments that fit the late-1960s collector market well. Choosing the brand usually comes after confirming the correct size and deciding on the construction you want.
Fitting & Setup
What rim width do 1968 Jaguar tires require?
Rim width requirements for 1968 Jaguar tires vary by size. The 185R15 radial fits rim widths from 4.5 to 6.5 inches depending on product. The 640-15 bias-ply appears on rims from 4.0 to 5.0 inches. The 205R14 radial fits 5.5 to 7.5 inches, and the 775-14 bias-ply fits 5.0 to 6.0 inches where a range is given.
That spread is one reason a simple wheel-diameter match is not enough when ordering for a 1968 Jaguar. A 15-inch wheel may still be too narrow or too wide for a particular tire version, especially when comparing a classic bias-ply to a metric radial. Confirm the actual wheel width on the car before settling on a size, particularly if the car has been restored or changed over the years.
Do 1968 Jaguar tires require inner tubes?
Tube requirements on 1968 Jaguar tires depend on the exact size and product. The 185R15 Michelin radial versions are marked TL, which identifies them as tubeless, and the 205R14 Michelin radial is also marked TL. The bias-ply sizes 640-15 and 775-14 do not carry a TL marking in the available product details, so tube use should be confirmed against the specific tire’s sidewall marking and the wheel design actually on the car.
That distinction matters because tube fitment is never just a tire question on a vintage Jaguar; it also depends on whether the wheel itself is appropriate for tubeless service. Before mounting, verify both the tire marking and the wheel type so the finished setup matches the product’s intended use. That step is especially important on older cars that may have changed wheels at some point in their lives.
Can the original 1968 Jaguar wheels be used with both tire sizes?
Some original 1968 Jaguar wheels can be used with more than one tire size, but only within the same wheel diameter family. The 340 and XKE share 15-inch fitments in both 185R15 and 640-15, and the 420 can also use those 15-inch sizes when fitted with 15-inch wheels. The 420’s 205R14 and 775-14 sizes, however, require 14-inch wheels and are not interchangeable with the 15-inch options.
The safe way to approach this is to treat diameter first and width second. If your 1968 Jaguar already has the correct 15-inch wheel, you may be choosing between radial and bias-ply within that wheel diameter, subject to rim width confirmation. If your car has 14-inch wheels, stay within the 420’s 14-inch sizes rather than trying to force a 15-inch solution.
Maintenance, Storage & Longevity
How should I store a 1968 Jaguar when the tires are fitted?
A 1968 Jaguar should be stored in a cool, dry, dark space away from direct sunlight, electric motors, welders, battery chargers, and other ozone-producing equipment. Keep the tires properly inflated, avoid prolonged contact with standing moisture, and move the car periodically if possible. Bias-ply tires can develop flat spotting more readily during long static storage, while both bias-ply and radial tires can suffer sidewall aging if they sit near heat and ozone sources.
If the car will be parked for an extended season, many collectors reduce strain on the tires by rolling the car occasionally or supporting it in a way that limits constant loading. Clean storage conditions matter just as much as tread depth on an older Jaguar, because age and environment often affect collector tires more than mileage does.
How long do tires on a 1968 Jaguar typically last?
On a 1968 Jaguar, tire life is usually judged by age and condition more than by miles traveled. A collector car tire should be evaluated closely once it reaches the five- to seven-year range, and around ten years is a common point for serious replacement consideration even if the tread still looks good. The DOT date code on the tire helps establish age, while cracking, hardening, vibration, or recurring air loss are stronger warnings than mileage alone.
That age-based approach matters because many Jaguars from this period cover limited annual miles and spend long stretches in storage. A tire that appears visually acceptable can still age out before it wears out. If the car’s service history is unclear, checking the date code is one of the quickest ways to understand whether the tires are still appropriate for regular road use.
How often should tires on a 1968 Jaguar be inspected?
Tires on a 1968 Jaguar should be inspected before every drive and again before any longer outing or highway trip. Look for sidewall cracking, cuts, bulges, uneven wear, nails, and signs that the tire is losing pressure. If your setup uses tube-type construction, include the valve stems and any symptoms of slow leakage in that routine.
Frequent inspection is especially important on older British cars because they are often driven less often than modern vehicles, which makes age-related issues easier to miss. A quick walkaround catches problems before they become roadside failures. It also gives you a chance to compare all four tires and the spare for age, condition, and consistency before putting more miles on the car.
Restoration & Authenticity
What tires were originally fitted to the 1968 Jaguar 340?
For a 1968 Jaguar 340, the period-correct starting point is bias-ply construction in the original size family rather than a modern radial by default. The 340 uses 15-inch fitments, and the bias-ply size in that group is 640-15. Radial 185R15 alternatives exist for the same model, but a buyer pursuing strict originality would normally treat the bias-ply option as the closer match to how many cars of the era were first equipped.
Original fitment details can still vary by market, wheel equipment, and restoration history, so concours-level work benefits from checking factory literature and Jaguar marque resources before making a final choice. Construction type, sidewall style, and overall visual stance can all affect how authentic the finished car appears, especially on a compact saloon like the 340.
Does correct tire fitment matter for showing a 1968 Jaguar?
Correct tire fitment absolutely matters when showing a 1968 Jaguar. Judges and knowledgeable enthusiasts often notice whether the tire size, construction type, and sidewall style look appropriate for the car’s year, model, and restoration approach. A radial on a car judged for strict originality, or a sidewall treatment that feels out of place for the model’s period presentation, can draw attention even when the tire physically fits the wheel.
That does not mean every show requires the same standard. Club events, driving tours, and marque-specific concours can apply authenticity differently, so the smart approach is to match your tires to the level of originality your event expects. If the car is a road-driven restoration rather than a points car, many owners balance appearance and usability instead of chasing absolute factory-style detail.
What is the difference between Michelin XVS and Coker Classic Radial for the 1968 Jaguar?
For a 1968 Jaguar in 185R15, Michelin XVS and Coker Classic Radial differ in sidewall treatments, speed ratings, and rim-width coverage. Coker Classic Radial appears as a redline tire with a 5.00 to 6.50-inch rim-width range and a 1355-pound maximum load at 35 psi. Michelin XVS comes in narrow whitewall and blackwall forms, with H-rated versions carrying a 130 mph ceiling and a V-rated version carrying a 149 mph ceiling, and rim-width ranges from 4.5 to 6.5 inches depending on version.
The practical choice comes down to appearance and how closely you want the tire’s character to align with the Jaguar’s final presentation. A redline creates a very different visual statement from a blackwall or narrow whitewall, even when the nominal size is the same. On a car like a 340 or XKE, that visual decision can change the entire stance of the restoration.
Safety & Road Use
Are 1968 Jaguar tires safe for highway driving?
1968 Jaguar tires can be suitable for highway driving when they are the correct size, in good condition, properly mounted, and used within their speed capability. Among the radial options, 185R15 appears with H and V ratings, carrying speed ceilings of 130 mph and 149 mph, while 205R14 appears with a W rating, carrying a 168 mph ceiling. The bias-ply sizes 640-15 and 775-14 do not show modern speed letters here, so they should be approached with the expectations appropriate to vintage bias-ply construction.
On most 1968 Jaguars driven on normal roads, tire condition and vehicle condition matter more than headline top-speed potential. Brakes, suspension condition, alignment, steering response, and the age of the tires themselves all shape real-world safety on an older Jaguar. A properly maintained car on the correct tire is far more reassuring than a neglected one wearing an impressive speed letter.
What inflation pressure should I use for 1968 Jaguar tires?
Inflation pressure on a 1968 Jaguar should follow the vehicle manufacturer’s recommendation first, with the tire maker’s rated pressure used as a reference for the reproduction or modern tire itself. Among the available products, 185R15 includes a version rated at 1355 pounds at 35 psi, 640-15 includes versions rated at 970 pounds at 32 psi and 1190 pounds at 32 psi, and 775-14 includes versions rated at 1580 pounds at 32 psi. Those figures are tied to specific tires and should not be transferred from one size to another.
That matters because pressure is part of the tire’s load-carrying specification, not a universal setting for every 1968 Jaguar. Start with the factory recommendation for your exact model and wheel setup, then confirm that the selected tire’s own construction and load rating are being respected. Pressure that is too high or too low can affect ride, wear, and handling even when the tire size itself is correct.
What should I check before taking a 1968 Jaguar on a longer drive?
Before taking a 1968 Jaguar on a longer drive, inspect all four road tires and the spare for cracking, cuts, bulges, uneven wear, and proper inflation. Check valve stems, and if your setup uses tube-type construction, pay close attention to any signs of slow air loss. A close look at tread depth and overall tire age is just as important as checking whether the car simply feels drivable around town.
A longer trip in a vintage Jaguar also calls for a broader mechanical once-over, since tire readiness is only one part of the equation. Confirm that the brakes, cooling system, steering, and suspension are in sound condition and that the spare and jack are usable. That kind of pre-drive discipline is part of enjoying an older Jaguar confidently rather than discovering age-related issues miles from home.
