Tire Size 305/70r18 vs 295/70r18

The 305/70r18 and 295/70r18 tires are just a few millimeters apart, but the difference between them is powerful enough to transform any driver’s experience. The 305/70R18 is equivalent to 34.8x12R18, and 295/70R18 is equivalent to 34.3×11.6R18. If you’re considering switching from one to the other, you’ve come to the right place!

305/70r18 vs 295/70r18 Table

Feature 295/70r18 305/70r18 Differences
Diameter 34.26″ 34.81″ 0.55 (1.6%)
Width 11.61″ 12.01″ 0.39 (3.4%)
Circum. 107.63″ 109.36″ 1.73 (1.6%)
Sidewall Height 8.13″ 8.41″ 0.28 (3.4%)
Revolutions 588.68 579.36 9.32 (1.6%)

Alternative Tire Size Of 305/70r18
This table displays the tire sizes with their overall diameter and the percentage difference from the 295/70R18 tire size, which has a diameter of 34.3 inches.

Tire Size Overall Diameter Difference
295/70R18 34.3″ (871 mm) -1.6%
345/60R18 34.3″ (871 mm) -1.6%
325/65R18 34.6″ (879 mm) -0.7%
285/75R18 34.8″ (885 mm) 0%
275/80R18 35.3″ (897 mm) 1.4%
315/70R18 35.4″ (899 mm) 1.6%
375/60R18 35.7″ (907 mm) 2.5%

Alternative Tire Size Of 295/70r18
The percentage difference can be useful in determining the impact of switching to a different tire size on factors such as speedometer accuracy and ground clearance.

Tire Size Overall Diameter Difference
325/60R18 33.3″ (847 mm) -2.8%
305/65R18 33.6″ (853 mm) -2.1%
285/70R18 33.7″ (857 mm) -1.6%
345/60R18 34.3″ (871 mm) 0%
325/65R18 34.6″ (879 mm) 0.9%
305/70R18 34.8″ (885 mm) 1.6%
285/75R18 34.8″ (885 mm) 1.6%
275/80R18 35.3″ (897 mm) 3%

Overall Diameter
The 295 70r18 and the 305 70r18 tires differ significantly in their overall diameter. The 305 70r18 has a larger diameter of 34.81 inches (884.2 mm), while the 295 70r18 has a smaller diameter of 34.26 inches (870.2 mm). 

This makes the 305 70r18 tire taller, with more ground clearance, but it also increases its center of gravity, which can impact handling and stability.

Tire Width
The width of a tire is the measurement from sidewall to sidewall. The width of a 305 70r18 tire is 305 millimeters. The width of a 295 70r18 tire is 295 millimeters. As you can see, the 305 70r18 tire is wider than the 295 70r18 tires by ten millimeters.

A wider tire provides a more contact patch with the ground, translating into improved traction, handling, and stability. It’s especially important in wet or slippery road conditions where having a bigger contact patch can be beneficial in keeping you safe on the road.

Aspect Ratio
The aspect ratio is the height of the Tire’s sidewall expressed as a percentage of the width. In other words, it is the height of the Tire from the bead to the top of the tread divided by the width of the Tire. The aspect ratio of a 305 70r18 tire is 70%.

This means that the height of the sidewall is 70% of the width of the Tire, which is 213.5 millimeters. The aspect ratio of a 295 70r18 tire is also 70% which is 206.5 millimeters. As you can see, the only difference between these two sizes is the width of the Tire 7 millimeters.

Construction Type
Both 305 70r18 and 295 70r18 tires are radial tires. Radial tires are the most common type of tire on the market today. They are made with steel belts that run around the circumference of the Tire. Radial tires differ from bias-ply tires because they feature steel belts that run perpendicular to the tread direction, providing better fuel efficiency, longer tread life, and improved handling.

Sidewall Height
Another essential characteristic for any vehicle tire is its sidewall height. This impacts how much of the tire’s surface area is in contact with the road at any given moment and how much it can absorb potential shock from road imperfections and impacts.

The 305/70r18 has a taller sidewall height of 8.41 inches compared to 8.13 inches for the 295/70r18. Shorter sidewalls can lead to firmer ride experiences and lower impact absorption. In comparison, taller sidewalls can result in more contact with the ground to provide better stability and traction.

Rim Size
The last number in a tire size is the diameter of the wheel that the Tire can be mounted on. Both 305 70r18 and 295 70r18 tires can be mounted on 18-inch wheels. If you have a set of 18-inch wheels and you are trying to decide between these two sizes, it comes down to personal preference.

The 305/70r18 has a larger circumference of 109.1 inches compared to 107.9 inches for the 295/70r18. This is a difference of 1.73 inches or 1.6% decrease, meaning that the 305/70r18 tire requires slightly more revolutions to cover the same distance than the 295/70R18 tire, resulting in marginally increased wear on it over time.

Revolutions Per Mile
It’s important to understand the revolutions per mile of tires when comparing them.  The 305/70r18 has a lower revolutions per mile of 579.36 compared to 588.68 for the 295/70r18. This means that the 305/70r18 will rotate fewer times to cover the same distance, which can result in improved fuel economy.

Our Observation
We believe that the 305/70r18 is a better option for off-road enthusiasts and those looking for an aggressive look, while the 295/70r18 is more suitable for daily driving and highway use. However, it is important to consider all the factors discussed in this article and weigh the pros and cons of each tire size to make an informed decision.

Selecting the right tire size is a crucial decision that can impact the performance and safety of your vehicle. By considering the factors discussed in this article and evaluating your specific needs, you can make an informed decision between the tire size 305/70r18 and 295/70r18 that best fits your requirements.

How Big Is A 305/70r18 Tire?

A 305/70R18 tire has a width of 305 millimeters, an aspect ratio of 70%, and fits an 18-inch wheel. To determine the tire’s overall diameter, we can use the following formula:

  • Overall diameter = (2x Sidewall height) + Wheel diameter

First, we need to calculate the sidewall height, which is the product of the tire width and aspect ratio:
Sidewall height = 305 mm x 70% = 0.70 x 305 mm ≈ 213.5 mm

Now, we can calculate the overall diameter:

  • Overall diameter = (2 x 213.5 mm) + (18 inches x 25.4 mm/inch)
  • Overall diameter = 427 mm + 457.2 mm
  • Overall diameter = 884.2 mm

So, a 305/70R18 tire has an approximate overall diameter of 884.2 millimeters or about 34.8 inches.

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