How Big Is A 305 Tire? |  Everything You Need to Know!

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Tires come in a wide assortment of sizes and dimensions depending on the make and model of your car, your preference, and your budget.

The overall dimension of your tires significantly influences the comfort of driving, the traction and stability you’ll get, and the fuel economy. 

So, what about the tires of performance cars, such as 305s? How big is a 305 tire? A 305 tire has a 12-inch tread width, which signifies it is bigger.

While the tire width is constant, you’ll find 305 tires with different height measurements based on the rim size. If your vehicle demands a 305 tire but hesitates to pick this one, our article will guide you with everything you need to know. 

Does Tire Size Really Matter?

It’s tempting to think any tire will work on your car’s wheels, but this is nothing but a massive misconception! In fact, each model is created to handle a particular kind of tire.

So remember, when you’re choosing a tire, don’t automate it with a model meant for a different tire size! 

Your tires are the only part of your vehicle that touches the ground when it’s in motion. The compression and abrasion of your tires will determine how conveniently you can handle the car.

You must understand the variables such as the make and model of your as well as the nature of the landscape you’ll travel on. As an example, an engine that’s bigger than others might require a significantly larger size tire. 

Similarly, it would help if you used a smaller tire for a flat surface, for example, a bare road. Wider, better-performing tires will be necessary if you want to drive over uneven terrain.

How Big is a 305 Tire?


Now it’s time to focus on the core of our discussion. The size of a tire is mainly determined by two variables, which are width and height.

However, the width of a tire is the prime determinant that lets us anticipate how big a tire is. In terms of a 305 tire, its width is 12 inches. From the technical point of view, it’s 305 mm.

However, the standard and the most used unit is  “inch.” So, a 305 is 1 foot wide! Now you can imagine how big these tires are. 

This is the reason 305 tires are commonly used in larger and high-performance vehicles or vehicles with extreme tuning. However, the height of the tire is also crucial. 

But in this case, you can see several variations of 305 tires based on the rim size, but the width remains constant. Here is a chart showing the measurements below:

P-Metric SizeRim SizeTire HeightTire With
305/70R1616 inches32.8 inches12.0 inches
305/60R1818 inches32.4 inches12.0 inches
305/70R1818 inches34.8 inches12.0 inches
305/55R2020 inches33.2 inches12.0 inches

So, the largest-diameter wheel may bear the tire and is secured against being blown over by a patch with a diameter of 20 inches.

The total diameter, 33.2 inches, represents the radius applied by the tire’s circumference. The outside diameter of a 305 tire measures approximately 104 inches.

Do 305 Tires Have Better Stability Than Thinner Tires?

Yes, 305 tires provide a bit of extra stability compared to thinner tires. This is because the track is more expensive, and the weight is distributed better due to a broader tread.

The bigger the tread, the better the stability will be, and here the center of gravity plays the principal role. The center of gravity pertains to a center of mass where the whole weight of the automobile is concerned.

Your car will be more stable as the center of gravity lowers down since that mass is distributed across a greater cross-section of the vehicle. A wide tire just initiates the same effect by spreading the total load in more space.

Do 305 Tires Offer More Traction?

In practice, wider tires are supposed to offer better grip. So in and of itself, a similar principle also applies to a 305 tire. Once again, the credit goes to its large contact area.

The larger tread patch increases friction, providing a more stable and reliable grip, especially when driving on dry roads.

If you compare two cars side-by-side with more compact and wider ones, the stopping distance of the wider tires will be less. Moreover, the vehicle can accelerate quicker with wider tires thanks to lower skidding.

Nevertheless, the situation is utterly different in wet conditions. The narrower the tire, the more it cuts through standing water. This logic also applies to snow and ice.

Does the Increased Width of 305 Tires Influence Their Load Capacity?

As we mentioned, your car’s tires are the only components connecting your vehicle to the ground. So, how the weight of your vehicle will be distributed depends on your tires. 

If your vehicle has wide tires, they cover a larger surface area, allowing you to carry more weight. If you have a truck and are often transporting heavy loads, wider tires will make your car more sturdy with the appropriate weight. 

Nevertheless, this does not suggest that it makes more sense to get larger tires when towing frequently. With a wide tire like the 305, less horsepower will be transmitted to the engine due to the larger contact patch.

Are 305 Tires More Robust Than Thinner Tires?

Extra bulk on wider 305 tires gives increased handling and better mass control. More extensive and heavier, the tire barely falls to lose balance. It allows greater vehicle control, so it’s more robust than a typical tire in nearly all instances.

This is the reason many performance cars have wider tires, as these are specifically designed to deal with fast directional changes quickly. 

Furthermore, wide tires allow vehicles to maneuver more effortlessly in off-road regions. This dramatically increases the capacity of shock absorbers as well.

Why Should You Avoid a Wide Tire Like the 305?

305 tires have a variety of advantages over their counterparts. Still, there are a few circumstances where you’d need to steer clear of them. Here are some of the negative aspects of 305 tires:

Decreased Power Efficiency

One of the most concerning factors regarding wide 305 tires is decreased power efficiency. If the wheels are wider, they require more force to get going. This implies that your engine will be more stressed and lose some power output.

Lower Fuel Economy

A wide 305 tire’s greater friction will raise its rolling resistance, adversely impacting fuel efficiency. A bigger rim assembly may make it too cumbersome for your car. This increases fuel consumption significantly.


For budget shoppers, the price tag of massive 305 tires can bring wrinkles on the forehead. Yes, 305 tires are more extensive than ordinary tires. Various factors influence the cost of 305 tires, including the fact that they are less common and less mass-produced.

In contrast to conventional tires, they have been developed to meet the unique demands of performance cars. These tires are also more complex due to their unique layouts and compounds, making them more expensive.

Inefficiency in Wet Conditions

We have already hinted that thinner tires are more suitable in wet conditions and outperform their wider counterparts.

So, this is the most concerning fact regarding 305 tires when you have to deal with wet, snow, or icy road conditions regularly.

Technically, there’s an increased risk of aquaplaning through deeper puddles of water with a wider tire. This means you may suddenly notice steering responsiveness while driving in wet conditions.

Shorter Lifespan

Wide tires like 305 tires have a shorter lifespan, especially on high-performance vehicles, and are more challenging to change corners quickly and deftly.

By changing your tire dimensions in other ways, you may find yourself facing more hassle with your transmission.


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