Bias Ply & Euro-Metric Tires:

165R15, 145R15 & 135R15 Tires compared to common tire sizing.


Tire technology and more important to our conversation, the way tires are sized, has changed immensely since VWs first came to the US. The stock tire size for a 1954 Beetle would have had a 6.00-15 bias ply tire. That didn’t change for the most part and even into the 1970s, the tire would have been a 5.60-15 or a 6.00-15, with a 155SR15 radial tire being an option. Either way, none of those tire sizes are what we or most tire shops are familiar with today.

Deciphering a bias ply tire size to a modern size can be confusing so most tire retailers will have a reference chart to help. For example, a 6.00-15 radial equivalent would be a 165R15. That still isn’t what we are used to seeing on a tire today. It’s a Euro-Metric size and in short, it is an “82” series (or Aspect Ratio) tire or a 165/82R15 in modern terms. 82 isn’t an Aspect Ratio offered today so it is rounded down and considered an 80 series tire and a 165/80R15 is what we offer as the stock, modern replacement tire for Beetles, Karmann Ghias & Type 3s.

Using that same method, we can convert a 145R15 tire to a 145/80R15 and a 135R15 converts to a 135/80R15. Additionally, we can then use those modern sizes at any number of online tire calculators to help choose a new tire size if you’re looking for a taller or shorter tire. You can also use it to compare widths of tires. Stock VW tires, and especially the smaller 145s and 135s are fine for a stock or vintage look but don’t offer much in the way of performance. The tread width, especially on the smaller tires leaves a lot to be desired when it comes to traction and braking capability as the narrow tire doesn’t have a large footprint.

Euro-Metric Modern Metric Diameter
(Inches)
Tire Width
(Inches)
Sidewall Height
(Inches)
"82" (IE 165/82R15) (unloaded) (not tread width) (unloaded)
165SR15 165/80R15 25.4 6.5 5.2
Wider Option 185/70R15 25.2 7.3 5.1
145SR15 145/80R15 24.1 5.7 4.6
Wider Option 175/65R15 24 6.9 4.5
135SR15 135/80R15 23.5 5.3 4.3
Wider Option 165/65R15 23.4 6.5 4.2

For reference or as an example, here are some tires that are all roughly the same diameter but starting with the 185 tire, the tires get wider than stock. The Aspect Ratio or “series” changes so that the tire diameter is close to stock.

6.00-15, 165R15, 165/80R15 (6.5” wide), 185/70R15 (7.3” wide), 195/70R15 (7.7” wide), 205/65R15 (8.1” wide), 215/60R15 (8.5” wide), 225/60R15 (8.9” wide)

Wider tires may require wider wheels and may not fit under the fender of your VW so make sure to check the fitment before committing to a tire size.

How to Read Your Tire:


Tire Section Width:

Tire section width refers to the width of the tire from sidewall to sidewall. Width is measured in millimeters, and is the first three numbers on the tire size marking. In our example "165/80R15" the 165 designated our tire is 165mm wide.

VW Tire Section

Aspect Ratio (Tire Profile Height):

Tire Aspect Ratio (or "series" of the tire) is measured in percent and refers to the ratio of height to width of the tire. Aspect Ratio is read as the two digits after the slash in a tire size marking. In our example "165/80R15" we find 80 is our aspect ratio. This tells us our tire height is 80% of 165mm. A little math (165 multiplied by .8) gives us the tire profile, 132mm.

VW Tire Profile

Construction:

The "R" in our "165/80R15" tire designates radial construction. Radial construction means the tire body cords run across the section width of the tire, and are aligned 90 degrees from direction of travel. Radial are built with alternating layers of belts and caps stacked in the tread section. In other words, a radial tire offers thinner sidewalls and thicker treads.

Radial Construction grants a flexible sidewall for cornering impact absorption while keeping a larger tread footprint on the ground. VW tires were originally manufactured with Bias-Ply construction however, as we mention above, Bias ply tires are rarely used today.

VW Tire Construction

Wheel Diameter:

Rim Diameter refers to the inside diameter of the wheel in inches. Most stock VW's had 14" or 15" rims depending on the year and model. Beetle, Karmann Ghia and Type 3 models typically ran 15" wheels, Type 2 models and Things typically had 14" wheels.

VW Rim Diameter

There are several factors that affect tire fitment. Wider or taller than stock tires could cause issues with tires rubbing the body or fender. A wheel could be too wide or the offset could be wrong causing the tire and wheel to sit too close to the body or too close to the fender. Ride height too can change the fitment. Wornout and sagging suspension can cause issues with stock tires and wheels not fitting well, just as lowering the car would. Making sure that everything on the suspension is correct is the first step in choosing a wheel and tire combination that will fit well.



Volkswagen Tire Options:


VW Stock Tire 165/80R15

The 165/80R15 is the modern day replacement for the factory size 165SR15 tire. For most all Beetles, Ghias and Type 3s this is the stock replacement tire. The obsolete 165SR15 tire did not list aspect ratio, but did list a speed rating of "S" (112mph). The modern day 165/80R15 tires list a slightly higher speed rating of "T" (118mph) as well as a load index of "87" (1,202 lb per tire) so they are more than suitable.

The 165/80R15 tire will fit the stock VW 15x4.5" wheel. It will also fit all of our aftermarket 15" wheels in widths from 4" to 6.5".

** This tire is closest to stock VW tire size and considered by most the "standard fitment" tire.

VW Tire 145R15

The 145R15 is a lower than stock profile tire. It is both smaller in diameter (it is shorter) and width (it is narrower) than stock. If you are lowering the front of your vehicle you will most likely need a smaller than stock tire. This is a necessity if you are installing drop spindles or lowering struts. Stock tires will not clear if you are lowering your vehicle! The 145R15 tire will fit the stock VW 15x4.5" wheel. It will also fit all of our aftermarket 15" wheels in widths from 4" to 5.5". Due to the very narrow tread width we recommend only using the 145R15 tire on the front of your car.

145R15 Tires do not state Aspect Ratio on the tire size marking but as we mention above is basically a 145/80R15.

VW Tire 135R15

The 135R15 is a lower than stock profile tire. It is both smaller in diameter (it is shorter) and width (it is narrower) than stock. It is smaller still than a 145R15 tire as well. If you are lowering the front of your vehicle you will most commonly need a smaller than stock tire. This is a necessity if you are installing drop spindles or lowering struts. Stock tires will not clear if you are lowering your vehicle! The 135R15 tire will fit the stock VW 15x4.5" wheel. It will also fit all of our aftermarket 15" wheels in widths from 4" to 5.5". Due to the very narrow tread width we recommend only using the 135R15 tire on the front of your car.

135R15 Tires do not state Aspect Ratio on the tire size marking but as we mention above is basically a 135/80R15.