Gardner 150 Series Tires

The Gardner 150 Series uses two listed tire sizes for 1930: 30X6.20 and 650-18. The 650-18 size corresponds to an 18-inch rim diameter, with listed products fitting rim widths from 3.25 to 3.50 inches. The 30X6.20 size uses an older diameter-by-section code, where the wheel diameter is not stated in the size itself.

That means a Gardner 150 Series owner should not assume the two codes are interchangeable just because they appear under the same year. Start by checking the tire marking on the car, then confirm the actual wheel diameter before selecting a replacement. On a late pre-war luxury car like the Gardner 150 Series, wheel and tire changes over the years are common enough that careful verification matters.

On a Gardner 150 Series, 30X6.20 is an antique diameter-by-section size. The 30 refers to the tire’s approximate overall outside diameter in inches, while 6.20 refers to nominal section width. Unlike later balloon and modern tire codes, that first number is not the wheel diameter.

That distinction is important because many modern buyers naturally read the first number as a rim size. With a Gardner 150 Series, the safer approach is to inspect the wheel itself and compare the existing tire markings before choosing a replacement. If the car has already been refitted at some point in its life, the wheel and the tire code on the sidewall will tell you more than the year by itself.

A 1930 Gardner 150 Series has two tire sizes listed because the model year is associated with two different size-designation systems: 30X6.20 and 650-18. One is an older overall-diameter-by-section format, while the other is a balloon-era numeric size tied to an 18-inch wheel. That kind of overlap is typical of transitional late pre-war fitment practice.

For an owner, the practical takeaway is that the year alone does not settle the question. You need to identify which wheel and tire convention your Gardner 150 Series actually carries today, especially if the car has had restoration work or wheel changes over time. The existing wheel diameter, rim width, and tire markings should all agree before you settle on a replacement size.

The currently listed Gardner 150 Series products in 650-18 are bias-ply tires, and bias-ply collector tires of this type use tubes. The older 30X6.20 designation also belongs to an earlier non-radial sizing system where tube-type fitment is the normal expectation. For a 1930 Gardner 150 Series, tube use should be treated as part of the correct fitment approach.

That makes wheel condition especially important on a collector car that sees limited use. When fitting tires to a Gardner 150 Series, inspect the rim well, valve area, and any hardware that could affect the tube. A fresh tube, proper flap where required, and careful mounting practice will do as much for reliability as the tire choice itself.

The right way to confirm a 1930 Gardner 150 Series tire size is to compare three things: the size marked on the current tire, the wheel’s actual rim diameter, and the tire convention used on the car. The two listed Gardner 150 Series sizes are 30X6.20 and 650-18, and they should not be treated as the same size written two different ways. The 650-18 fitment is specifically tied to an 18-inch rim.

On an older restored car, start with the wheel because that is the least ambiguous measurement. If the car carries 18-inch wheels with rim widths in the 3.25 to 3.50 inch range, that points strongly toward 650-18. If the car still wears older-format tires marked 30X6.20, confirm that the wheel and body clearance support that setup before changing anything.

Gardner 150 Series tires in the available 650-18 products come in two sidewall styles: Wide Whitewall and Blackwall. Both are offered in the Firestone Balloon series. That gives owners a choice between a brighter period look and a more restrained presentation.

The right sidewall style depends on how the Gardner 150 Series is being presented. A blackwall usually suits a more understated, formal pre-war appearance, while a wide whitewall can emphasize late-1920s to early-1930s visual character. For serious restoration work, the best approach is to match the sidewall treatment to period photos, factory literature, or established marque practice for the specific car.

The listed Gardner 150 Series products are from Firestone. The available products in 650-18 are both part of the Firestone Balloon line, with one blackwall option and one 3.50 inch whitewall option. No other tire brand appears in the current Gardner 150 Series product set.

That means brand selection is straightforward, but size verification still matters more than brand recognition on a car like the Gardner 150 Series. Once the correct wheel diameter and tire code have been confirmed, the owner can focus on presentation details such as sidewall style and the period-correct look of a balloon-profile bias-ply tire.

A Gardner 150 Series should be stored in a cool, dry, dark space with the tires kept away from direct sunlight, electric motors, welders, heaters, and solvents that can accelerate rubber aging. Proper inflation matters even in storage, because an underinflated collector tire can develop flat spotting or sidewall stress while the car sits. Clean, dry floors and stable temperatures are better for both the tire casing and the tube.

If a Gardner 150 Series sits for long periods, move it slightly from time to time or place it on stands in a way that does not strain the suspension or chassis. The goal is to reduce static load on one contact patch for months at a time. Collector tires often age out long before they wear out, so storage conditions play a major role in how well they stay serviceable.

Tires on a Gardner 150 Series should be inspected before every meaningful drive and again during routine seasonal maintenance, even if the car covers very few miles. Look for cracking, weathering, uneven wear, tread separation, cuts, bead issues, and signs of tube or valve-stem trouble. On a pre-war car, long periods of inactivity can be as hard on tires as road use.

A hands-on inspection is especially important with bias-ply collector tires because the car may be used only occasionally and problems can go unnoticed. Check inflation when the tires are cold, and inspect the wheel as well as the tire. If the Gardner 150 Series has been parked for months, a thorough inspection before the next outing is a sound habit.

Tires on a Gardner 150 Series should be replaced when age, cracking, hardening, casing distortion, or any structural concern appears, even if the tread still looks usable. Low-mile collector cars often preserve tread while the rubber itself continues to age. On a pre-war Gardner 150 Series, age-related deterioration is a more common replacement trigger than worn-out tread depth.

That is why condition matters more than appearance alone. Any tire that shows visible aging, vibration issues, repeated pressure loss, or questionable casing integrity deserves professional evaluation and likely replacement. For a collector car that may spend much of its life parked, conservative replacement timing is usually wiser than trying to extract the last possible miles from an aging set.

The Gardner 150 Series is associated here with two period-correct size conventions for 1930: 30X6.20 and 650-18. The currently listed product line for the balloon-size fitment is Firestone Balloon, offered in blackwall and wide whitewall forms. That tells you the Gardner 150 Series sits in the era where older dimensional sizing and balloon-era sizing can overlap.

For restoration work, the exact original fitment for a specific Gardner 150 Series should be checked against factory literature, surviving original cars, or established marque references. Tire size, sidewall treatment, and overall profile can all affect authenticity. On a high-end pre-war automobile, getting those visual details right has a real effect on how convincingly the finished car presents.

Correct tire fitment can absolutely affect how a Gardner 150 Series is judged and how seriously the restoration is taken. On a pre-war luxury automobile, judges and experienced enthusiasts notice whether the tire size, sidewall style, and overall stance suit the year and character of the car. A tire that is technically mountable but visually out of period can change the whole presentation.

That matters not only for show judging but also for the car’s market credibility. Buyers tend to trust a Gardner 150 Series more when the visible details suggest careful research rather than convenience fitment. If authenticity is the goal, compare the finished look against period imagery and seek marque-club input before settling on blackwall versus whitewall and on the final size convention.

The available Gardner 150 Series sidewall styles in 650-18 are Blackwall and Wide Whitewall. Either can suit the broad pre-war period depending on the exact character of the restoration, the trim level, and the way the car was presented when new or later in its life. The sidewall choice influences not just appearance but the car’s visual stance and era impression.

A blackwall usually supports a more conservative and formal restoration, while a wide whitewall can emphasize luxury presence and late-1920s to early-1930s styling. The best answer for a Gardner 150 Series comes from period photos, sales literature, or trusted marque references for the exact body and presentation. Matching sidewall style to the intended restoration standard will produce a more coherent result.

A correctly fitted, properly mounted collector tire can be suitable for limited public-road use on a Gardner 150 Series when the tire size, wheel condition, inflation, and overall vehicle condition are all in order. The available products here are bias-ply designs, so the driving feel will remain appropriate to a 1930 automobile rather than a modern car. Road use expectations should stay within the car’s original character and braking capability.

Safe use depends on the whole vehicle, not just the tire. Before any regular driving, a Gardner 150 Series should have its steering, suspension, brakes, wheels, and alignment checked to the same standard as the tires themselves. A well-sorted pre-war car can be enjoyable on secondary roads and event driving, but it should always be operated with period-appropriate caution.

Before driving a Gardner 150 Series, check cold tire pressure, visible condition, valve stems, wheel security, and any signs of cracking, bulging, or impact damage. Confirm that all four tires match the intended fitment and that the spare is also serviceable if the car is expected to travel beyond local show use. On a 1930 car, basic roadworthiness checks deserve more attention than they do on a modern daily driver.

It is also wise to pay attention to how the Gardner 150 Series feels in the first miles. Any pull, vibration, steering wander, or unusual noise should be investigated before continuing. Collector cars often spend long periods parked, so a careful pre-drive routine helps catch age-related tire issues before they become roadside problems.

A Gardner 150 Series should be driven at moderate, period-appropriate speeds that respect the limits of a 1930 chassis, bias-ply tires, mechanical condition, and road environment. Even when the tires are new collector reproductions, the car itself was not designed around modern highway expectations. Smooth, conservative motoring is the right mindset for a pre-war luxury automobile.

In practice, that means avoiding sustained high-speed running and treating the car more like an event, touring, or fair-weather secondary-road machine than a modern interstate cruiser. The correct pace is the one that keeps the Gardner 150 Series stable, comfortable, and mechanically unstrained. Tire preservation, passenger safety, and the car’s long-term health all benefit from restraint.