840/820-15 Tire Size Guide

The 840/820-15 is a vintage multi-width numeric size. In this code, the 8.40 and 8.20 figures refer to nominal width designations used in older sizing practice, and the 15 identifies the wheel diameter in inches. It is a bias-ply-era passenger-car format rather than a modern metric one.

Modern P-metric sizes usually spell out width in millimeters, aspect ratio, construction, and rim diameter in one string. The 840/820-15 does not do that. Instead, it reflects an earlier system where width and rim diameter were the key identifiers, and buyers still need to check actual wheel width, sidewall proportions, and clearance on the vehicle before treating it as a direct stand-in for any newer size.

The 840/820-15 tire fits a 15-inch wheel, which is 381 millimeters in diameter. That wheel diameter must match exactly, because bead seat diameter is not interchangeable across nearby tire sizes that may look similar at a glance.

Wheel width matters too. This size is shown on rims from 6.00 to 6.50 inches wide, which is the range to compare against your actual wheel before mounting. A correct diameter with the wrong width can still create profile distortion, sidewall shape issues, or clearance problems, so the wheel should be measured rather than assumed from appearance alone.

The 840/820-15 has a section width of 8.4 inches. In metric terms, that is about 213.4 millimeters. Section width refers to the tire's broadest point from sidewall to sidewall when inflated, not the width of the tread that actually contacts the road.

Clearance checks should focus on section width because sidewall bulge is what usually comes closest to fenders, suspension parts, and steering components. Tread width is normally narrower and can be misleading if you are judging space by eye. On a vintage passenger car, even small differences in section width can affect turning clearance and the way the tire fills the wheel opening.

Yes, the 840/820-15 and 840 820 15 refer to the same tire size. The difference is only in how the size is written. One version uses a slash and dash, while the other separates the same figures with spaces.

Vintage tire sizes often appear in several notation styles across old catalogs, sidewalls, and vehicle paperwork. Buyers should focus on the actual numbers and rim diameter rather than punctuation alone. Even so, the writing style does not answer every fitment question, because wheel width, tire construction, and physical clearance still need to be confirmed on the specific car and wheel being used.

The 840/820-15 is commonly a tube-type fitment and is often set up with a tube. Tube use is still a wheel-and-tire-system question rather than a size-only question, so the final decision should be confirmed against the actual wheel and tire being used.

Many vintage wheels and vintage-style tires rely on details beyond the size code alone, including wheel design, bead condition, and the tire's own construction and markings. If you are mounting this size on original equipment wheels, restored rims, or reproduction wheels, confirm the proper tube setup before service so the entire assembly matches the intended use and road conditions.

The 840/820-15 weighs 26 pounds per tire in the currently represented version. That figure is the shipping weight of the tire itself without the wheel, and it gives a useful reference point when comparing this size with heavier-duty or lighter modern alternatives.

Tire weight does not determine fitment by itself, but it does influence unsprung weight and the general feel of the suspension. On a restored passenger car, keeping all four tires consistent matters more than chasing the lightest number. Matching construction, size, and weight across the set helps preserve predictable ride behavior and a balanced period-correct stance.

The 840/820-15 is strongly associated with classic passenger cars from the 1940s through the early 1960s, and its bias-ply construction suits the appearance and driving character expected from that period. For many restorations, that makes it a more authentic-looking choice than a modern radial substitute with noticeably different sidewall shape.

Originality-minded owners should still compare the size against factory documentation, surviving original tires, or trusted restoration references for the exact vehicle. Cars from the same era sometimes used more than one size depending on trim, body style, or optional equipment. Matching the wheel diameter is only the first step; wheel width, body clearance, and the intended judging standard also matter.

The 840/820-15 is built for a 15-inch wheel and is shown on rims from 6.00 to 6.50 inches wide. Both measurements matter. A correct 15-inch diameter with an out-of-range wheel width can still produce a poor profile or create clearance issues once the tire is mounted and inflated.

Buyers using original steel wheels, restored wheels, or reproduction rims should verify actual wheel width at the bead seats rather than measuring the outer lip. Vintage wheels are often described casually by nominal size, and that can lead to assumptions. Checking both diameter and width helps preserve the intended sidewall shape and reduces the chance of interference at full steering lock or under suspension movement.

No. Sharing a 15-inch rim diameter does not automatically make another vintage size interchangeable with the 840/820-15. Width, sidewall profile, load capacity, and overall proportions all influence whether the tire will clear the body and maintain the look and behavior you want.

Substitution decisions on older cars should begin with the original size recommendation and then move to practical checks. Compare wheel width, section width, and vehicle clearance, and consider whether a change will alter stance or the fullness of the wheel opening. On classic passenger cars, even a modest size change can affect steering clearance and visual balance more than expected.

The 840/820-15 uses bias-ply construction, so it generally delivers the road feel, sidewall movement, and steering character typical of older passenger cars rather than the more settled response many drivers expect from modern radials. That driving experience is part of why restorers choose it when preserving factory-era behavior and appearance.

Suspension condition, alignment, wheel trueness, and tire age all influence how a bias-ply car feels on the road. A well-sorted vintage chassis can drive very differently from a worn one even on the same size tire. Buyers returning a classic to regular road use should think about whether originality or modernized feel matters more for the way the car will actually be driven.

The 840/820-15 belongs to a tall-sidewall vintage format, and that usually contributes to the softer visual profile and period-correct ride character associated with classic passenger cars. Comfort in real use comes not only from sidewall height, but also from bias-ply construction, wheel width, inflation, and the condition of the vehicle's suspension.

Owners should judge ride quality as part of the whole chassis rather than from the tire size alone. Worn bushings, weak shocks, uneven alignment, or old wheels can make any vintage tire feel harsher or less stable than expected. On a properly prepared car, this size is typically chosen for preserving authentic proportions and the classic road manners that go with them.

Yes, the 840/820-15 can have a noticeable effect on steering feel because bias-ply construction reacts differently from a radial in turn-in, tracking, and sidewall flex. Many owners associate that response with the original character of mid-century passenger cars, especially on vehicles kept close to stock in suspension and wheel choice.

Handling results depend heavily on setup. Alignment settings, steering wear, wheel condition, and whether the full set matches all influence how predictable the car feels. Mixing constructions or using mismatched sizes can change the way the vehicle responds, so consistency across all four corners is usually more important than judging the 840/820-15 by construction type alone.

The 840/820-15 is available from US Royal in the current represented selection. Since this is a specialty vintage size, buyers usually evaluate the offering less by broad brand count and more by whether the tire's construction, appearance, and dimensions suit the car they are restoring or driving.

Brand choice in an older size should be tied to your goals. A buyer focused on concours-style appearance may prioritize period-correct construction and sidewall treatment, while someone building a road car may focus more on load rating consistency and matched-set uniformity. Even with a known vintage name, wheel compatibility and condition checks still come first.

Quality in the 840/820-15 size starts with correct sizing, consistent bias-ply construction, and a tire that matches the intended use of a classic passenger car. Buyers should also look for a load rating appropriate to the vehicle, a wheel width match within 6.00 to 6.50 inches, and consistent specifications across the full set.

Appearance matters too, especially on pre-1960s and early-1960s restorations where the tire is a major visual element. A narrow whitewall can change the car's presentation just as much as wheel choice. The best approach is to treat quality as a combination of dimensional accuracy, construction integrity, period-correct look, and predictable behavior once all four tires are mounted and balanced.

Yes, the narrow whitewall can be an important part of the 840/820-15 decision because sidewall appearance strongly affects how a classic passenger car presents. On many vintage builds, the difference between a narrow whitewall and a plain black sidewall changes the overall character of the car even when the mechanical fitment stays the same.

Restoration-minded buyers should compare the sidewall treatment to the era and trim level they are trying to reflect. A whitewall that looks right for one build may feel out of place on another. Sidewall style should be chosen alongside size, construction, and wheel fitment so the finished car looks coherent rather than simply wearing the correct diameter.

The 840/820-15 should be inspected regularly for cracking, bulges, cuts, tread separation, uneven wear, and slow air loss. Bias-ply tires on collector cars may spend long periods parked, and age can affect serviceability even when tread depth still looks acceptable from a quick glance.

Owners should inspect sidewalls and tread before longer drives and after seasonal storage. Heat, sunlight, ozone exposure, and long periods without movement can accelerate aging on older-style tires. If the car develops vibration, pull, or unusual wear, the tire, wheel, alignment, and suspension should all be checked together rather than assuming the size itself is the only cause.

The 840/820-15 will last better when stored away from direct sunlight, moisture, strong heat sources, and ozone-producing equipment such as electric motors or compressors. Clean, dry storage conditions matter because time and environment can age a collector tire even when the car is rarely driven.

If the vehicle sits for extended periods, keep the tires properly inflated, move the car occasionally if practical, and inspect for flat spotting or sidewall changes before returning it to the road. Vintage bias-ply tires are often chosen for authenticity, so preserving them means caring for the entire wheel-and-tire assembly rather than focusing on tread alone.

The 840/820-15 is commonly a tube-type fitment and is often set up with a tube, but tube service should always be confirmed from the actual wheel and tire combination. The condition and design of the wheel matter just as much as the size when deciding how the assembly should be put into service.

When mounting or servicing an older wheel, inspect the inside of the rim, valve hole area, and bead seats carefully. A tube, flap, or related hardware should never be chosen casually because the wrong setup can create avoidable problems in use. If there is any uncertainty, a qualified tire professional should evaluate the complete assembly before the car goes back on the road.

The 840/820-15 should be replaced when inspection shows cracking, bulges, persistent air loss, impact damage, irregular wear, or other signs that the tire's structure may no longer be dependable. Tread depth alone is not enough, especially on vintage and collector vehicles that may see low mileage but still experience age-related deterioration.

Before longer trips, owners should check the tire's overall condition, the wheel's condition, and whether all four tires remain matched in size and construction. Bias-ply tires can age out before they wear out. If there is any doubt about condition, service history, or storage exposure, the safer course is to have the tire evaluated before continued road use.

The represented 840/820-15 is rated at 1,920 pounds at 32 psi per tire. Buyers should compare that figure to the actual weight demands of the vehicle, including passengers, luggage, and the way the car is used, rather than relying on the size name alone to suggest adequate capacity.

Load verification matters most on larger passenger cars where curb weight can vary meaningfully between body styles and equipment levels. Inflation and load belong together, so the load figure should always be read with its matching pressure rather than separated from it. If the vehicle's requirements are unclear, check factory documentation or consult a qualified tire professional.

Yes. Buyers should confirm that the 840/820-15 matches the wheel diameter, wheel width, load needs, and overall condition required for the vehicle before regular road use. Because this is a vintage bias-ply size commonly associated with tube-type setups, the complete wheel-and-tire assembly deserves careful inspection before sustained driving.

Longer trips call for extra attention to air retention, visible sidewall condition, and any change in steering feel or vibration. Local road-use requirements and inspection expectations can vary, so current sidewall markings and the actual installed setup should be reviewed rather than assumed. A size-correct tire is only one part of a roadworthy vintage wheel and tire package.