1951 Kaiser Tire Fitment Guide

1951 Kaiser vehicles use two tire sizes: 670-15 and 710-15. Both sizes apply to the full model range covered here, including the 1951 Kaiser K511 and 1951 Kaiser K512, and both mount on 15-inch wheels. The 670-15 products shown fit 15-inch rims in a 4.50 to 6.00-inch range depending on the specific tire, while 710-15 products fit 15-inch rims in a 5.00 to 5.50-inch range.

That means the key question is not which model you own, but which of the two original-style sizes your particular car and wheels are set up for. Checking the tires already on the car, the wheel width, and any restoration records will usually point you in the right direction before you narrow the choice further by brand or sidewall style.

A 670-15 tire for 1951 Kaiser uses the older numeric bias-ply sizing system. The 6.70 designation refers to the tire's nominal section width, and the 15 identifies the wheel diameter in inches. On 1951 Kaiser applications, 670-15 is a bias-ply fitment rather than a radial or metric size.

Modern buyers often expect a tire code to include an aspect ratio and construction letter, but older American sizing usually did not show those details in the code itself. For a 1951 Kaiser, the practical takeaway is to treat 670-15 as a period-style 15-inch bias-ply size and then verify the specific tire's approved rim-width range before making a final selection.

A 710-15 tire for 1951 Kaiser is another numeric bias-ply size. The 7.10 portion indicates a nominally wider section than 6.70, and the 15 again refers to a 15-inch wheel diameter. Like 670-15, it is an older bias-ply size format rather than a modern radial code.

The important difference for a 1951 Kaiser owner is that 710-15 changes the tire's overall visual proportion and width while keeping the same wheel diameter. If your Kaiser is already running 15-inch wheels, the next step is confirming whether the wheel width and the car's existing setup align with 710-15 rather than assuming both sizes are interchangeable in every case.

Both 670-15 and 710-15 are correct-style bias-ply choices for 1951 Kaiser vehicles, and both are used on the K511 and K512. The difference is mainly size and proportion, not a switch between bias-ply and radial construction. A 670-15 product may fit rims as narrow as 4.50 inches depending on the tire, while 710-15 products shown here call for 5.00 to 5.50-inch rims.

The best way to choose between them is to confirm what size your car already carries, what wheel width is actually on the car, and whether your restoration goal favors the narrower or wider original-style look. If your Kaiser has been through wheel or tire changes over the years, verify the wheel before settling on either size.

1951 Kaiser tires are available in both blackwall and wide whitewall styles. The 670-15 size includes blackwall and wide whitewall options, and the 710-15 size does as well. That gives owners a choice between a more understated appearance and the fuller whitewall presentation that suits many early-1950s American restorations.

Sidewall style does not change the basic fitment, but it can change the finished character of the car dramatically. A show-oriented 1951 Kaiser often looks most at home on a wide whitewall, while a blackwall can suit a more restrained restoration or a car intended to reflect a plainer, more utilitarian presentation.

Several brands offer tires for 1951 Kaiser applications. In 670-15, the available brands include Firestone, US Royal, Coker Classic, and Universal Vintage Tire. In 710-15, the available brands include BFGoodrich and Firestone, all within bias-ply offerings sized for 15-inch Kaiser fitments.

That brand spread gives a 1951 Kaiser owner room to choose by appearance details, preferred vintage brand identity, and the exact size needed for the car. Once you know whether your Kaiser requires 670-15 or 710-15, comparing the sidewall treatment and rim-width range within that size is usually the most useful next step.

Rim-width requirements for 1951 Kaiser tires depend on the size selected. In 670-15, available tires cover rim widths from 4.50 to 6.00 inches depending on the specific product. In 710-15, the products shown are intended for 5.00 to 5.50-inch rims.

That range matters because two tires with the same nominal size may not approve the exact same wheel width. Before fitting a new set to a 1951 Kaiser, measure the wheel or confirm the wheel specification already on the car, then match it to the approved range for the exact tire you plan to use.

Original-diameter 1951 Kaiser wheels can be compatible with both listed tire sizes in the basic sense that 670-15 and 710-15 are both 15-inch tires. Wheel diameter alone, however, is only part of the picture. The approved rim-width range changes by size and sometimes by product within the same size.

A 15-inch wheel that works well with one 1951 Kaiser tire size may still need to be checked carefully before moving to the other size. If you are considering a switch between 670-15 and 710-15, confirm the actual wheel width first so the tire's approved range and the wheel's dimensions stay aligned.

A 1951 Kaiser should be stored away from direct sunlight, electric motors, welders, generators, and other ozone-producing equipment that can accelerate sidewall aging. Keep the car in a clean, dry space and maintain normal operating inflation rather than letting the tires sit underinflated. Because 1951 Kaiser fitments here are bias-ply, they are especially prone to temporary flat-spotting after long static storage.

Moving the car periodically can help reduce flat spotting and keep the carcass from sitting in one loaded position for months at a time. For longer-term storage, some owners also use stands or reposition the car occasionally, but the most important habits are stable pressure, a cool environment, and protection from ozone and moisture.

Tires on a 1951 Kaiser should be judged more by age and condition than by mileage, because collector cars often cover relatively few miles each year. A good rule is to begin evaluating tires closely once they reach the five- to seven-year range and to treat around ten years as the point when replacement deserves serious consideration, even if the tread still looks good. The DOT date code on the tire helps establish age.

That timeline matters because rubber compounds age from time, heat cycles, and storage conditions as much as from road use. A lightly driven 1951 Kaiser can still end up with aged tires that look serviceable at first glance, so age, cracking, and ride behavior should all be part of the decision rather than tread depth alone.

Tires on a 1951 Kaiser should be inspected before every drive and again before any extended outing or event. Look for sidewall cracking, tread separation signs, cuts, bulges, uneven wear, and slow pressure loss. On an older collector car, valve stems deserve the same attention because they age alongside the tires.

Frequent inspection is especially important when the car spends long periods parked between drives. A quick walkaround before using a 1951 Kaiser can catch aging-related issues early and can also reveal whether one tire is carrying less pressure than the rest, which affects ride quality, wear, and overall confidence on the road.

A 1951 Kaiser K511 would have been fitted in the bias-ply era, so bias-ply construction is the correct starting point for an authentic restoration. The sizes used across the 1951 Kaiser range here are 670-15 and 710-15, both in bias-ply form and both mounted on 15-inch wheels. No specific original-equipment tire brand should be assumed without factory literature or marque-specific confirmation.

For restoration purposes, that means a 1951 Kaiser owner should first confirm which of the two sizes belongs on the individual car and then decide what sidewall appearance matches the intended presentation. If you are preparing for marque judging or trying to match a specific market or trim-level history, a Kaiser club or period sales material is the right place to verify that final detail.

Correct tire fitment matters a great deal when showing a 1951 Kaiser because judges and knowledgeable enthusiasts often notice size, construction, and sidewall presentation immediately. A tire that has the wrong overall type for the era, the wrong size for the car, or a sidewall treatment that conflicts with the intended restoration theme can distract from an otherwise well-finished car.

For a 1951 Kaiser, the safest path toward authenticity is staying with the proper bias-ply construction and confirming whether the car should wear 670-15 or 710-15. Whitewall width and brand identity can also influence the final impression, so owners aiming for formal judging should compare their tire choice against event standards and marque-club expectations before finalizing the setup.

Within the 670-15 size for 1951 Kaiser, Firestone and US Royal share the same listed load rating of 1450 pounds at 32 psi and the same listed 15-inch rim diameter with a 4.50 to 5.00-inch rim-width range. The visible difference in the examples shown is sidewall treatment, with Firestone offered as a blackwall and US Royal offered as a wide whitewall, along with a one-pound difference in listed weight.

That makes the comparison less about fitment and more about presentation. A 1951 Kaiser owner deciding between those two 670-15 options is largely choosing whether the car should carry a blackwall look or a broad whitewall look, while keeping the same basic size, load rating, and approved wheel-width range within the 670-15 category.

1951 Kaiser tires can be suitable for normal highway use when they are the correct size, in sound condition, and properly inflated, but the products shown here do not list speed ratings in the tire size markings provided. With a collector-era car like a 1951 Kaiser, roadworthiness depends just as much on the condition of the suspension, steering, brakes, and wheels as it does on the tires themselves.

That means highway confidence comes from treating the tire as one part of the overall system rather than assuming any fresh tire makes the whole car ready for sustained speed. If your Kaiser will see regular longer drives, pay close attention to age, pressure retention, balance, and the general mechanical readiness of the car before venturing far from home.

Available 1951 Kaiser tire listings show load-and-pressure figures of 1450 pounds at 32 psi for some 670-15 tires and 1550 pounds at 32 psi for other 670-15 examples as well as the 710-15 tires shown here. Those figures are load capacities at a stated tire pressure, not a universal factory setting for every Kaiser application. The original owner's literature remains the right source for the car's intended operating pressure.

Use the vehicle recommendation as your starting point, then make sure it remains appropriate for the exact reproduction tire and the way the car is used. What matters most is avoiding the temptation to apply one pressure rule across both 670-15 and 710-15 simply because they share a 15-inch wheel diameter.

Before a longer drive in a 1951 Kaiser, inspect each tire for sidewall cracking, cuts, bulges, irregular wear, and any sign of age-related deterioration. Check inflation pressure when the tires are cold, inspect the valve stems, and make sure the spare is present and usable. On a collector car from this era, wheel fasteners, steering feel, and brake behavior deserve equal attention before the trip begins.

A careful pre-drive routine reduces the chances that an old-car outing is interrupted by a preventable tire problem. Even if the tires look visually appealing on a restored 1951 Kaiser, age, long storage periods, and infrequent use can hide issues that only show up once the car is driven at speed or over a longer distance.