The 1986 Bertone X-1/9 represents the final chapter of a distinctive mid-engine Italian sports car that had already earned a loyal following for its compact proportions, sharp styling, and nimble road manners. By this point, the X-1/9 was very much a specialist enthusiast car, and tire choice plays a real role in preserving the feel that makes it so appealing. The 1986 Bertone X-1/9 uses a 165/70R13 radial tire on a 13-inch rim. That keeps the decision focused on selecting the right metric radial fitment and maintaining the car’s balance, steering response, and overall period character for road use or careful preservation.
Which Tire Size Is Right for The 1986 Bertone X-1/9
The 1986 Bertone X-1/9 uses one primary tire size: 165/70R13, a radial tire for a 13-inch rim. The Base sub-model shares that same fitment, so the main decision is not which size fits, but how closely the tire’s dimensions, construction, and overall character suit the car’s original-style handling and intended use.
The size 165/70R13 is a metric radial format: 165 is the nominal section width in millimeters, 70 is the aspect ratio, R identifies radial construction, and 13 is the wheel diameter in inches. On the 1986 Bertone X-1/9, that sizing supports the compact, responsive feel expected from a small mid-engine sports car. Because this is already a modern metric radial size, the buyer’s focus is usually on choosing a tire that maintains the proper overall proportions and wheel compatibility. It is also wise to confirm the actual wheel setup if the car has been modified over the years.
Sub-model fitment is straightforward for the 1986 Bertone X-1/9. The covered Base model uses the same tire size, so the key step is confirming that the car still has its proper 13-inch wheel setup before selecting tires.
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1986 Bertone X-1/9 Base
The 1986 Bertone X-1/9 Base uses the 165/70R13 radial tire size. That keeps tire selection centered on choosing the right metric radial fitment for the car’s 13-inch wheels and checking whether any later wheel or suspension changes could affect clearance or overall stance.
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.
Frequently Asked Questions
These FAQs focus on 1986 Bertone X-1/9 tire size, 13-inch rim fitment, radial-tire selection, period-minded appearance, and the checks worth making before putting a lightly used collector sports car back on the road.
Tire Size & Fitment
What tire size fits a 1986 Bertone X-1/9?
The 1986 Bertone X-1/9 uses a 165/70R13 radial tire. That is the primary fitment for this model year, and the Base sub-model uses the same size, so there is no separate sub-model tire-size split to sort through on this page.
The important next step is confirming that the car still has the correct 13-inch wheels and has not been changed to a different wheel package over time. On an older X-1/9, aftermarket wheels, suspension changes, or bodywork adjustments can affect what actually clears the car even when the original tire size is known.
What size rim does a 1986 Bertone X-1/9 use?
The 1986 Bertone X-1/9 uses a 13-inch rim with its 165/70R13 tire size. In that metric radial sizing format, the final number always refers to wheel diameter, so the tire is built for a 13-inch wheel rather than a larger modern compact-car rim.
Wheel diameter is only part of the fitment picture, especially on a small sports car with tight packaging. It is still smart to verify wheel width, check for non-stock offsets, and look at steering and fender clearance before mounting new tires, particularly if the car has spent years in collector use or has had cosmetic or suspension changes.
What does 165/70R13 mean on a 1986 Bertone X-1/9?
On a 1986 Bertone X-1/9, 165/70R13 is a metric radial size. The 165 is the nominal section width in millimeters, 70 is the aspect ratio, R means radial construction, and 13 is the wheel diameter in inches.
That combination matters because it defines the basic proportions of the tire, not just the wheel size. Staying with the correct size format helps preserve the X-1/9’s steering feel and overall balance, while any change in width or profile should be checked carefully against the actual wheels on the car and the available room under the body.
Choosing the Right Tire
What should I consider when choosing a 165/70R13 tire for a 1986 Bertone X-1/9?
Start with the correct size and construction: the 1986 Bertone X-1/9 uses a 165/70R13 radial on a 13-inch rim. After that, the main considerations are whether the tire suits the car’s intended use, whether its dimensions align properly with the wheel, and whether it preserves the balanced feel expected from a lightweight mid-engine sports car.
A practical choice also depends on the car itself, not just the catalog size. Check the current wheel width, inspect for rubbing marks or clearance issues, and think about whether the X-1/9 will see regular road driving, occasional fair-weather use, or mostly display duty. Those details help narrow the right tire character without changing the proper fitment.
How do I choose between available 165/70R13 tires for a 1986 Bertone X-1/9?
Choosing between 165/70R13 tires for a 1986 Bertone X-1/9 usually comes down to maintaining the correct size while matching the tire to the way the car will be used. A lightly driven collector car may call for a different selection approach than an X-1/9 that is exercised regularly on back roads or local events.
It helps to compare overall tire character rather than chasing a generic idea of performance. Look at how the tire fits the wheel, whether it keeps the car’s proportions looking right, and whether the construction and profile support the steering response you want. On a small Italian sports car, even modest fitment changes can alter both appearance and feel.
Why is staying with the correct tire size important on a 1986 Bertone X-1/9?
Staying with the correct 165/70R13 size helps keep the 1986 Bertone X-1/9 close to the proportions it was designed around. On a compact mid-engine car, tire size affects more than appearance; it influences steering response, visual stance, and how the car sits within the wheel openings.
That does not mean every car is still exactly as built, especially after decades of ownership and modifications. Confirm the actual wheel package on the car, inspect suspension condition, and make sure there is proper clearance at full steering lock and over suspension movement. Those checks matter before trying anything outside the original-size baseline.
Restoration & Appearance
Which tire should I choose for a period-style 1986 Bertone X-1/9?
For a period-style 1986 Bertone X-1/9, the right starting point is the correct 165/70R13 radial size on a 13-inch wheel. Keeping the original size format preserves the compact proportions that suit the car’s wedge-shaped body and helps avoid the oversized look that can come from later wheel-and-tire substitutions.
Appearance-focused buyers usually benefit from treating size accuracy as the first priority and everything else as a secondary choice. If absolute originality matters, compare any tire under consideration against marque-specific references, period photos, or restoration documentation for the exact car. That approach is more reliable than assuming any modern tire in the size automatically matches the car’s original presentation.
Does correct tire fitment matter for a 1986 Bertone X-1/9 restoration?
Correct tire fitment matters on a 1986 Bertone X-1/9 restoration because the car is small, visually delicate, and closely tied to its wheel-and-tire proportions. A 165/70R13 radial keeps the restoration grounded in the proper size family rather than drifting into a more generic modern compact-car look.
Fitment also affects how convincing the finished car feels on the road. A tire that is too wide, too tall, or mounted on the wrong wheel can change stance, steering effort, and clearance. Even on a driver-level restoration, checking the actual wheel diameter, width, and suspension setup is worthwhile before settling on the final tire choice.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1986 Bertone X-1/9?
Yes, modifications can affect tire fitment on a 1986 Bertone X-1/9 even when the original tire size is known. Changes such as aftermarket wheels, different offsets, lowering, spring replacement, or body repairs can alter how much room the car has around the tire at the fender, suspension, and steering components.
That is especially important on a compact sports car where clearances are not generous to begin with. Before mounting new tires, check the actual wheel diameter and width, turn the steering through its full range, and look for any signs of prior rubbing. Those simple checks can prevent fitment surprises once the car is back on the road.
What should I inspect before driving a 1986 Bertone X-1/9 on new tires?
Before driving a 1986 Bertone X-1/9 on new tires, inspect the wheels for damage, confirm the tire size matches the car’s 165/70R13 fitment, and make sure the tires are seated and inflated properly. It is also worth checking alignment condition and looking over suspension and steering components for looseness or wear.
A collector-era X-1/9 may have spent long periods parked, so the rest of the chassis deserves attention too. Look for cracked bushings, leaking shocks, uneven old tire wear, and any interference marks inside the wheel housings. A short, careful test drive followed by another pressure and clearance check is a smart final step.
How should 165/70R13 tires on a collector 1986 Bertone X-1/9 be maintained?
165/70R13 tires on a collector 1986 Bertone X-1/9 should be kept at the proper pressure for the setup being used, inspected regularly for cracks, cuts, bulges, and uneven wear, and checked for air loss before each outing. Low-mileage collector cars can age their tires out long before they wear them out.
Storage conditions matter almost as much as mileage. Keep the car away from prolonged sunlight, excess heat, moisture, and ozone sources such as electric motors or compressors, and move it periodically so the tires are not supporting weight in one position for months at a time. That routine helps protect both tire condition and road readiness.
