295/70R17 vs 285/70R17 Side-by-side tire size comparison with specs and compatibility
This tire swap is within the safe 3% diameter threshold. It should not cause issues with speedometer accuracy, ABS, or traction control systems.
Full Specifications Comparison
| Specification | 295/70R17 | 285/70R17 | Difference |
|---|---|---|---|
| Overall Diameter | 844.8 mm (33.3") | 830.8 mm (32.7") | -14 mm |
| Section Width | 295 mm (11.6") | 285 mm (11.2") | -10 mm |
| Sidewall Height | 206.5 mm | 199.5 mm | -7 mm |
| Circumference | 2654 mm | 2610 mm | -44 mm |
| Revolutions/Mile | 606 | 617 | +11 |
| Aspect Ratio | 70% | 70% | 0% |
| Rim Diameter | 17" | 17" | 0" |
Key Impact Summary
Speedometer Correction Table
When switching from 295/70R17 to 285/70R17, your speedometer will over-read. Here is the correction at common speeds:
| Speedometer Shows | Actual Speed (mph) | Difference |
|---|---|---|
| 30 mph | 29.5 mph | -0.5 mph |
| 40 mph | 39.3 mph | -0.7 mph |
| 50 mph | 49.2 mph | -0.8 mph |
| 60 mph | 59 mph | -1 mph |
| 70 mph | 68.8 mph | -1.2 mph |
| 80 mph | 78.7 mph | -1.3 mph |
| 90 mph | 88.5 mph | -1.5 mph |
| 100 mph | 98.3 mph | -1.7 mph |
| 110 mph | 108.2 mph | -1.8 mph |
| 120 mph | 118 mph | -2 mph |
What This Swap Means
Narrower tires (285/70R17): The 10mm narrower contact patch reduces rolling resistance, potentially improving fuel economy. Narrower tires also cut through standing water better, reducing hydroplaning risk. However, dry grip and cornering stability may decrease slightly.
Shorter sidewall: The 7.0mm decrease in sidewall height improves steering response and cornering precision. However, ride quality becomes firmer and the wheels are more vulnerable to pothole damage. This is a common trade-off when upsizing wheels (plus-sizing).
Ground clearance: Decreases by 7mm, lowering the center of gravity slightly which can improve handling stability.