Car Tire Types: Seasons and Sizes.

The use of tires is something a car cannot do without. They are a main factor not only for the vehicle’s safety on the road, but for the comfort of driving as well. They compensate for the shortcomings of the road surface and offer good road traction. But not everything is the same. In this post, I’m going to explain the different car tire types.

Is the Tire’s Size Right?

You’ve maybe already heard how important the tire size is. For me, it took a while.

But let’s ask some questions:

👉 Why is that important?
👉 What could possibly happen if the tire size is not correct for my car?
👉 How can I know what is the right size for my car or how can I know the size of the tire?

Let me explain.

As you can see from the image, or maybe you already have seen those on your own tires, there are some letters and numbers from the outer side on every tire.

These characters show the exact parameters of every tire, so every letter or digit has its own purpose and means something.

I’m going to explain to you each one, using the example from the image above.

“P” – Tire Type.

The first letter indicates the class/type of the tire.

“P” means that the tires are for a “Passenger Vehicle”, such as the car you drive every day.

There may also be “LT”, which means that the tire is for Light Trucks or vehicles that are capable of carrying heavy loads.

IF the first letter is missing at all, it means that the tire is euro-metric or made by European standards. The absence of the first letter basically means that the tire is a generic or universal fit, not specifically designed for a particular type of vehicle.

 “185” – Width (in millimeters).

In our example, the tire’s width is 185 millimeters.

“75” – Aspect Ratio.

It indicates how tall is the sidewall as a percentage of the width.

In our example, the aspect ratio is 75. This means that the sidewall is 75% of the width, which in our case equals around 139 millimeters.

The higher the Aspect Ratio number is, the taller is the sidewall.

Usually sport cars’ tires have a lower number such as 30 or 40, while SUV’s and family vans have higher numbers in the range of 45-60 or even higher.

“R” – Construction of the Tire.

The number “R” means that the tire is Radial, which is practically the most, if not all the tires manufactured nowadays.

If the letter is “D” or if a letter is missing at all, it means that the tire is Diagonal. (See CARCASS)

“14” – Diameter of the Rims (in inches).

Indicates the diameter of the rims.

In our case 14 means that the tire is projected for mounting on 14 inch rims.

“82” – Load Rating Index.

Indicates how much load can the tire support.

In our case the index is 82. It means that this tire can support a maximum load of 1047 pounds or 475kg concentrated on it.

Four tires with the same load rating index of 82 can support up to 1900kg or 4188 pounds. Vehicle’s weight included.

Higher load index number – more load the tire can safely support. Usually the Load Rating Indexes are in the range of 71 to 130.

Below, I’m going to provide a chart for you, so you can know exactly what each load rating stands for. But did you know that overloading your vehicle can lead to a tire bursting? Read the top reasons that cause the tires to blow out.

Sometimes the Load Rating may be indicated with letters, as in most Light Truck tires.

➡️ LL (Light Load): These tires are designed for lighter loads. They typically have a load index ranging from 71 to 74. For example, an LL tire with a load index of 71 can support approximately 761 pounds (345 kilograms) per tire.

➡️ SL (Standard Load): Standard load tires are more common and versatile. Their load index varies from 75 to 100. For instance, an SL tire with a load index of 90 can handle around 1,323 pounds (600 kilograms) per tire.

➡️ XL (Extra Load): Extra load tires are reinforced to support heavy loads. Their load index starts from 101 and goes up. An XL tire with a load index of 105 can carry approximately 2,039 pounds (925 kilograms) per tire.

Remember that these load capacities are approximate and can vary based on the specific tire model. Always refer to the tire manufacturer’s specifications for precise load ratings.

“S” – Speed Rating.

It indicates the maximum speed the tire can safely support. In our case the letter “S” means that the tire can support a max speed of 180km/h or 112mph.

Below I will provide a graph with the Speed Rating indexes.

Keep in mind that those ratings are the safe speed the tires can support. We must always drive according to the speed limits and the road conditions.

The owner’s manual states what is the right tire size for your car.

Don’t skip those details, as driving with the wrong tire size may cause control issues that can lead to accidents.

I can say it from my own experience.

Going to the Beach or Going Skiing? Different Seasons Mean Different Tires. Or Not?

Car tires affect the behavior of the vehicle on the road.

Different car tire types are projected to suit the conditions of the road surface, the load of the vehicle and temperature. Theoretically, there is a tire type for every possible condition.

The Three Types of Seasonal Tires:

☀️ Summer Tires – Summer tires are made for road conditions without snow or icy surfaces.

Their rubber compound does NOT soften much at high temperatures, as well as the wearing at high speed is not that noticeable.

However, as the tread depth of the summer tires is low, their performance in rain is not as good as the winter tire.

Aquaplaning also occur more often. But we do have a guide on how to avoid the aquaplaning phenomenon. This one day may save your life!

❄️ Winter Tires – Winter tires are projected for lower temperatures and winter road conditions.

Their rubber compound is soft enough in lower temperatures so that better grip can be achieved.

When driving in colder temperatures and dry weather, it’s good to maintain slightly higher air pressure in winter tires compared to the manufacturer’s recommendation. Typically, this means 0.2 to 0.3 atmospheres (or approximately 3 to 4.5 psi) above the standard pressure.

The reason behind this adjustment is that as temperatures drop, the air pressure within the tires naturally decreases.

🌞❄️🌸🍂 All-Season Tires – They can be used both in the summer and in the winter.

They are a balanced version between both types and are mostly used in countries where the seasonal temperature differences are not that high, as some parts of Germany or the UK.

The profile of this type of tires combines the groove arrangements of the winter and summer tires, thus providing good performance in all seasons.

Investing in All-Season tires removes the necessity of changing your tires every season and also the necessity of having both winter and summer tires.

However, not everything can be perfect.

While they are the jack of all trades, they are master of none. They CANNOT be used in extreme conditions.

Conclusion

Always bear in mind your county’s climate and the meteorological conditions of your destination when choosing what car tires to utilize.

Choosing the right type will lead to better control of your vehicle and after all, you should always be master of your car.

Using different tire types in the wrong meteorological condition is dangerous and may lead to accidents. That’s why you should always be informed about the conditions at your desired destination, so you can prepare in advance. Always stay safe and protect your life and the life of the others!

The same goes with the size of the tires — always use the ones suggested by your car manufacturer.

Got a question or a doubt? Or maybe you have a story to share? Don’t hesitate to drop your comment below! I can’t wait to hear from you!