# What Are the Benefits of Using 275/65R18 vs 275/70R18 Tires? | Keywords: Tire Sizes, Differences

The difference between 275/65R18 and 275/70R18 is the second number, which indicates the tire’s aspect ratio or sidewall height, with the 70R18 having a higher profile.

## What’S The Difference Between 275/65R18 And 275/70R18

The main difference between 275/65R18 and 275/70R18 is the difference in the tire’s sidewall height. Specifically, at 275/65R18, the tire has a sidewall height of 6.7 inches, while at 275/70R18, it rises to 7.3 inches. Typically, taller tires have a larger contact patch with the ground and deliver additional traction as well as increased stability in turns. However, they also lead to shorter brake distances due to their higher rolling resistance. All in all, when selecting between these two sizes of tire, a driver should consider factors such as off-road performance, suspension travel and their individual needs – for example whether handling in turns or on-road comfort is important.

## Tire Sizes

The two tire sizes that we will be discussing are 275/65R18 and 275/70R18. These two sizes are the most common tire sizes for medium sized trucks and SUVs. Both of these tires have an 18 inch wheel diameter, but they differ in terms of width and sidewall height.

## Width

The width of a tire is the distance from its outermost point to the innermost point. The width of the 275/65R18 tire is 275 millimeters, while the width of the 275/70R18 tire is 70 millimeters wider, at 345 millimeters. This makes the 275/70R18 tire significantly wider than its counterpart.

## Sidewall Height

The sidewall height measures how tall a tires sidewalls are from its rim to its tread. The sidewall height of a 275/65R18 tire is 65 millimeters, while the sidewall height of a 275/70R18 tire is 70 millimeters taller at 135 millimeters. This makes the 275/70R18 tire noticeably taller than its counterpart.

## Rolling Diameter

The rolling diameter measures how large a tires circumference is when it is fully loaded and inflated to its proper pressure level. The rolling diameter of a 275/65R18 tire is 845 millimeters, while the rolling diameter of a 275/70R18 tire is 875 millimeters larger, at 1120 millimeters. This makes the 275/70R18 significantly larger than its counterpart in terms of circumference when it is fully loaded and inflated properly.

Overall, when comparing these two different sizes, there are distinct differences in terms of their width, sidewall height and rolling diameter measurements. The larger size (275/70R18) has a notably wider width as well as taller sidewalls and larger rolling diameter than its smaller sized counterpart (275/65R18).

## Profile Ratio

The profile ratio of a tire refers to the relationship between the height of the sidewall and the width of the tire. The first two digits of a tire’s size designation, such as 275/65R18, refer to the width and are measured in millimeters. The second two digits, such as 65 and 70 in the example above, refer to the profile ratio or sidewall height. This is expressed as a percentage of the tire’s width.

In our example, 275/65R18 has a profile ratio of 65%, meaning that its sidewall height is 65% of its width. A 275/70R18 has a profile ratio of 70%, meaning that its sidewall height is 70% of its width.

The difference between these two tires is that one has a higher profile ratio than the other. This means that for every millimeter wider the tire is, it will be 5% taller in terms of sidewall height. For example, if you compare a 275/65R18 with a 285/70R18, which are both 18 inch tires, you will note that even though they are both 10 millimeters wider than each other (275 mm vs 285 mm), they have different profile ratios (65% vs 70%). This means that while they are 10 millimeters wider than each other, they are actually 50 millimeters taller than each other (5% x 10mm = 50mm).

## FAQ & Answers

Q: What is the difference between 275/65R18 and 275/70R18?

A: The main difference between these tire sizes is the width and sidewall height. The 275/65R18 tire has a width of 275 millimeters and a sidewall height of 65 percent, while the 275/70R18 tire has a width of 275 millimeters and a sidewall height of 70 percent. Both tires have a rolling diameter of 18 inches and a profile ratio of 275/65R18.

Q: What is the width of each tire size?

A: Both tires have a width of 275 millimeters.

Q: What is the sidewall height for each tire size?

A: The sidewall height for the 275/65R18 tire is 65 percent, while the sidewall height for the 275/70R18 tire is 70 percent.

Q: What is the rolling diameter for each tire size?

A: Both tires have a rolling diameter of 18 inches.

Q: What is the profile ratio for each tire size?

A: The profile ratio for both tires is 275/65R18.

The main difference between 275/65R18 and 275/70R18 tires is the aspect ratio, which affects the tire’s overall diameter and profile. The 275/65R18 has a 65-percent aspect ratio, meaning that its sidewall height is 65-percent of its section width. In contrast, the 275/70R18 has a 70-percent aspect ratio, meaning that its sidewall height is 70-percent of its section width. As a result, the 275/70R18 tire has a larger overall diameter and a higher profile than the 275/65R18 tire.