Tire Size 245/75r16 vs 225/75r16
The tire sizes 245/75R16 and 225/75R16 are very similar, with the main difference being that the 245/75R16 tire is 1.18 inches (30 mm) larger in diameter. This difference in diameter will cause the speedometer to read 3.9% slower when using the 225/75R16 tires. The 245/75R16 tire will also have a slightly larger width and circumference.
225/75r16 vs 245/75r16 Table
Take a look at this convenient comparison table to gain a clear understanding of the distinctions between tire sizes 245/75R16 and 225/75R16.
| Feature | 225/75r16 | 245/75r16 | Difference |
|---|---|---|---|
| Diameter inches (mm) | 29.29 (743.9) | 30.47 (773.9) | 1.18 (30) |
| Width inches (mm) | 8.86 (225) | 9.65 (245) | 0.79 (20) |
| Circum. inches (mm) | 92.01 (2337.03) | 95.72 (2431.28) | 3.71 (94.25) |
| Sidewall Height inches (mm) | 6.64 (168.75) | 7.23 (183.75) | 0.59 (15) |
| Revolutions per mile (km) | 688.63 (427.89) | 661.93 (411.31) | -26.69 (-16.59) |
Overall Diameter
The overall diameter of a tire refers to the total height of the tire from the base to the top. The 225/75r16 tire has a diameter of 29.29 inches (743.9mm), while the 245/75r16 has a larger diameter of 30.47 inches (773.9mm).
This difference of 1.18 inches (30mm), or a 4% increase, can impact the vehicle’s speedometer accuracy, overall ground clearance, and how well the tire fills the wheel arch.
Larger-diameter tires can offer better ground clearance, which benefits off-road vehicles. However, they can also lead to inaccurate speedometer readings as they cover more ground per revolution. Conversely, smaller-diameter tires may offer more accurate speedometer readings but might reduce ground clearance.
Section Width
The section width is the linear distance between the widest points of a tire’s outer sidewalls, not including any protective ribs, bars, or decorations. The 225/75r16 has a width of 8.86 inches (225mm), while the 245/75r16 is wider, at 9.65 inches (245mm), reflecting an increase of 0.79 inches (20mm), or 8.9%.
A wider tire like the 245/75r16 provides a larger contact area with the road, increasing traction and stability, especially in wet conditions. On the downside, wider tires might increase rolling resistance, potentially reducing fuel efficiency. Conversely, narrower tires like the 225/75r16 can potentially offer better fuel efficiency but may provide less traction.
Circumference
The circumference refers to the distance a tire covers in one revolution. The 225/75r16 tire has a circumference of 92.01 inches (2337.03mm), while the 245/75r16 has a larger circumference of 95.72 inches (2431.28mm), a difference of 3.71 inches (94.25mm), or 4%.
The larger circumference of the 245/75r16 tire implies that it covers more ground per revolution. This could result in lower engine RPM at the same speed, potentially improving fuel efficiency at highway speeds. However, it may also lead to inaccurate speedometer readings.
Sidewall Height
The sidewall height, also known as the aspect ratio, is the tire’s height from the rim to the tread. The 225/75r16 tire has a sidewall height of 6.64 inches (168.75mm), while the 245/75r16 tire is taller at 7.23 inches (183.75mm), reflecting a difference of 0.59 inches (15mm), or 8.9%.
Tires with taller sidewalls like the 245/75r16 can absorb road bumps better, offering a smoother ride. However, they may also increase body roll in corners, impacting handling. Conversely, tires with shorter sidewalls, like the 225/75r16, offer better handling and responsiveness but may result in a stiffer ride.
Revolutions Per Mile
Revolutions per mile measure how many times a tire revolves in a mile. The 225/75r16 tire completes 688.63 revolutions per mile, while the 245/75r16 completes fewer revolutions at 661.93 per mile, a decrease of 26.69 revolutions, or -3.9%.
A tire with fewer revolutions per mile, like the 245/75r16, covers more ground with each revolution, potentially reducing engine RPM and improving fuel efficiency at high speeds.
However, it may also affect acceleration and speedometer readings. Conversely, a tire with more revolutions per mile, like the 225/75r16, offers more accurate speedometer readings and potentially better acceleration, albeit at the cost of increased engine RPM and fuel consumption.
Alternative of 225/75r16
The replacement tires must maintain an overall diameter that is within a 3% margin of the original tires.
| Tire Size | Overall Diameter | Difference |
|---|---|---|
| 225/70R16 | 28.4″ (722 mm) | -3% |
| 265/60R16 | 28.5″ (724 mm) | -2.7% |
| 215/75R16 | 28.7″ (728 mm) | -2.2% |
| 275/60R16 | 29″ (736 mm) | -1.1% |
| 235/70R16 | 29″ (736 mm) | -1.1% |
| 255/65R16 | 29.1″ (738 mm) | -0.8% |
| 285/60R16 | 29.4″ (748 mm) | 0.5% |
| 215/80R16 | 29.5″ (750 mm) | 0.8% |
| 245/70R16 | 29.5″ (750 mm) | 0.8% |
| 265/65R16 | 29.5″ (750 mm) | 0.8% |
| 315/55R16 | 29.6″ (752 mm) | 1.1% |
| 247/70R16 | 29.6″ (752 mm) | 1.1% |
| 235/75R16 | 29.8″ (758 mm) | 1.9% |
| 255/70R16 | 30.1″ (764 mm) | 2.7% |
| 275/65R16 | 30.1″ (764 mm) | 2.7% |
Alternative Tire Size of 245/75r16
The overall diameter of the replacement tires should not deviate more than 3% from that of the original tires.
| Tire Size | Overall Diameter | Difference |
|---|---|---|
| 315/55R16 | 29.6″ (752 mm) | -2.8% |
| 247/70R16 | 29.6″ (752 mm) | -2.8% |
| 235/75R16 | 29.8″ (758 mm) | -2.1% |
| 255/70R16 | 30.1″ (764 mm) | -1.3% |
| 275/65R16 | 30.1″ (764 mm) | -1.3% |
| 215/85R16 | 30.4″ (772 mm) | -0.3% |
| 285/65R16 | 30.6″ (776 mm) | 0.3% |
| 265/70R16 | 30.6″ (778 mm) | 0.5% |
| 235/80R16 | 30.8″ (782 mm) | 1% |
| 345/55R16 | 30.9″ (786 mm) | 1.6% |
| 225/85R16 | 31″ (788 mm) | 1.8% |
| 295/65R16 | 31.1″ (790 mm) | 2.1% |
| 275/70R16 | 31.2″ (792 mm) | 2.3% |
Our Observation
Choosing between the 225/75r16 and 245/75r16 tires depends on your specific needs and driving conditions. The 245/75r16 offers more traction, better ground clearance, and potentially better fuel efficiency at high speeds due to its larger size and width. This could make it an excellent choice for off-road driving or driving on slippery surfaces.
On the other hand, the 225/75r16, with its smaller size and narrower width, offers potentially better fuel efficiency, more responsive handling, and more accurate speedometer readings. This could make it a good choice for everyday driving and highway cruising.
Remember that changing tire sizes can impact vehicle performance and speedometer accuracy. If you are considering a tire size change, it’s advisable to consult with a tire or vehicle professional.
Meet Caitlin McCormack, a Tire Size Expert and Blogger Passionate About Everything Related to Tires. With Years of Experience in the Tire Industry, Caitlin Has Become an Expert in Tire Sizes and Their Impact on Vehicle Performance.