Tire Size 235/40r18 vs 245/40r18
The endless options and technical jargon can be confusing for the average driver. That’s why we’re here to help simplify the process by comparing two popular tire sizes, the 235/40r18 and 245/40r18. In short, 235/40R18 is equivalent to 25.4×9.3R18 and 245/40R18 is equivalent to 25.7×9.6R18.
235/40r18 vs 245/40r18 Table
| Specification | 235/40r18 | 245/40r18 | Difference |
|---|---|---|---|
| Diameter | 25.4″ | 25.72″ | 0.31 inches |
| Width | 9.25″ | 9.65″ | 0.39 inches |
| Circumference | 79.8″ | 80.79″ | 0.99 inches |
| Sidewall Height | 3.7″ | 3.86″ | 0.16 inches |
| Revolutions | 793.97 | 784.25 | 9.72 |
Alternative Tire Size for 245/40r18
It’s important to ensure that the overall diameter of the new tire is within 3% of the original tire. The 245/40r18 tire size has 60 compatible tire size options for replacement.
| Tire Size | Overall Diameter | Difference |
|---|---|---|
| 295/30R18 | 25″ (635 mm) | -2.8% |
| 255/35R18 | 25″ (635 mm) | -2.8% |
| 225/40R18 | 25.1″ (637 mm) | -2.5% |
| 305/30R18 | 25.2″ (641 mm) | -1.8% |
| 205/45R18 | 25.2″ (641 mm) | -1.8% |
| 265/35R18 | 25.3″ (643 mm) | -1.5% |
| 155/60R18 | 25.3″ (643 mm) | -1.5% |
| 145/65R18 | 25.4″ (645 mm) | -1.2% |
| 235/40R18 | 25.4″ (645 mm) | -1.2% |
| 315/30R18 | 25.5″ (647 mm) | -0.9% |
| 135/70R18 | 25.5″ (647 mm) | -0.9% |
| 275/35R18 | 25.6″ (649 mm) | -0.6% |
| 215/45R18 | 25.6″ (651 mm) | -0.3% |
| 285/35R18 | 25.9″ (657 mm) | 0.6% |
| 225/45R18 | 25.9″ (659 mm) | 0.9% |
| 335/30R18 | 25.9″ (659 mm) | 0.9% |
| 145/70R18 | 26″ (661 mm) | 1.2% |
| 255/40R18 | 26″ (661 mm) | 1.2% |
| 185/55R18 | 26″ (661 mm) | 1.2% |
| 205/50R18 | 26.1″ (663 mm) | 1.5% |
| 295/35R18 | 26.1″ (663 mm) | 1.5% |
| 345/30R18 | 26.2″ (665 mm) | 1.8% |
| 235/45R18 | 26.3″ (669 mm) | 2.5% |
| 265/40R18 | 26.3″ (669 mm) | 2.5% |
| 305/35R18 | 26.4″ (671 mm) | 2.8% |
Alternative Tire Size for 235/40r18
it’s crucial to make sure that the overall diameter of the new tire is no more than 3% different from the original tire. The 235/40r18 tire size offers 60 compatible tire sizes for replacement.
| Tire Size | Overall Diameter | Difference |
|---|---|---|
| 245/35R18 | 24.8″ (629 mm) | -2.5% |
| 285/30R18 | 24.8″ (629 mm) | -2.5% |
| 215/40R18 | 24.8″ (629 mm) | -2.5% |
| 125/70R18 | 24.9″ (633 mm) | -1.9% |
| 255/35R18 | 25″ (635 mm) | -1.6% |
| 225/40R18 | 25.1″ (637 mm) | -1.2% |
| 305/30R18 | 25.2″ (641 mm) | -0.6% |
| 205/45R18 | 25.2″ (641 mm) | -0.6% |
| 265/35R18 | 25.3″ (643 mm) | -0.3% |
| 155/60R18 | 25.3″ (643 mm) | -0.3% |
| 145/65R18 | 25.4″ (645 mm) | 0% |
| 315/30R18 | 25.5″ (647 mm) | 0.3% |
| 135/70R18 | 25.5″ (647 mm) | 0.3% |
| 275/35R18 | 25.6″ (649 mm) | 0.6% |
| 215/45R18 | 25.6″ (651 mm) | 0.9% |
| 245/40R18 | 25.7″ (653 mm) | 1.2% |
| 285/35R18 | 25.9″ (657 mm) | 1.9% |
| 225/45R18 | 25.9″ (659 mm) | 2.2% |
| 335/30R18 | 25.9″ (659 mm) | 2.2% |
| 185/55R18 | 26″ (661 mm) | 2.5% |
| 145/70R18 | 26″ (661 mm) | 2.5% |
| 295/35R18 | 26.1″ (663 mm) | 2.8% |
| 205/50R18 | 26.1″ (663 mm) | 2.8% |
Overall Diameter
The 235 40r18 size has an overall diameter of 25.4 inches, while the 245 40r18 size has an overall diameter of 25.72 inches. This means that the 245 40r18 sizes will be slightly larger in diameter than the 235 40r18 sizes. The difference in those tire sizes is 0.31 inches or about 1.2%.
The overall diameter is important to consider because it can affect your vehicle’s performance. Larger tires can provide better grip and handling, making your car less fuel efficient.
Section Width
The 235 40r18 size has a section width of 9.25 inches, while the 245 40r18 size has a section width of 9.65 inches. This means the 245 40r18 sizes will be about 4.3% wider than the 235 40r18 sizes.
The section width is important to consider because it can affect your vehicle’s performance. Wider tires can provide better grip and handling, but they can also make your car less fuel efficient.
Circumference
The 235 40r18 size has a circumference of 79.8 inches, while the 245 40r18 size has a circumference of 80.79 inches. This means that the 245 40r18 sizes will be about 0.99 inches or about 1.2%.
The difference in circumference is important to consider because it can affect the speedometer readings on your vehicle. If you’re planning to use the tires for racing, you’ll want to ensure that the speedometer is accurate.
Revolutions Per Mile
The 235 40r18 size has revolutions per mile of 793, while the 245 40r18 size has revolutions per mile of 784. This means that the 245 40r18 sizes will be about 1.2% smaller in circumference than the 235 40r18 sizes.
Sidewall Height
The 235 40r18 size has a sidewall height of 3.7 inches, while the 245 40r18 size has a sidewall height of 3.86 inches. This means that the 245 40r18 sizes will be about 0.16 inches or about 4.3% taller in sidewall height than the 235 40r18 sizes.
The sidewall height is essential to consider because it can affect your vehicle’s performance. Taller tires can provide better grip and handling, making your car less fuel efficient.
Wheel Size
The 235 40r18 size has a wheel size of 18 inches, while the 245 40r18 size also has a wheel size of 18 inches. This means there is no wheel size difference between the two sizes. The 235 40r18 and 245 40r18 sizes will both fit on 18-inch rims.
Construction Type
The 235 40r18 size is available in radial construction, while the 245 40r18 size is also available in radial construction. Radial tires are the most common type of tire construction, and they’re characterized by the steel belts that run radially around the tire. Radial tires are known for their durability, stability, and fuel efficiency.
Our Observation
Based on the comparison table, the 245/40r18 tire size is slightly larger in overall diameter, section width, circumference, and sidewall height compared to the 235/40r18 tire size. This means that the 245/40r18 tire size may offer better handling and a more comfortable ride.
However, the 235/40r18 tire size has a slightly higher RPM, which may result in better fuel efficiency. Ultimately, the choice between these two tire sizes depends on your personal preference and the specific needs of your vehicle.
