335/30R18 vs 255/45R17
255/45R17 is a safe swap for 335/30R18 by the usual ±3% rule: the diameter differs by +0.47%.
Speedometer and odometer
With 255/45R17 on a car calibrated for 335/30R18, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.3 mph |
| 70 mph | 70.3 mph |
| 80 mph | 80.4 mph |
Other sizes close to 335/30R18
- 335/30R18 vs 225/45R18+0.23%
- 335/30R18 vs 245/40R18-0.76%
- 335/30R18 vs 225/40R18-3.19%
- 335/30R18 vs 225/50R17-0.21%
- 335/30R18 vs 245/45R18+2.96%
- 335/30R18 vs 235/45R18+1.60%
- 335/30R18 vs 235/40R18-1.98%
- 335/30R18 vs 225/50R18+3.65%
- 335/30R18 vs 245/45R17-0.90%
- 335/30R18 vs 255/35R19+0.44%
- 335/30R18 vs 255/35R18-3.42%
- 335/30R18 vs 255/40R18+0.46%
Questions
Can I replace 335/30R18 with 255/45R17?
255/45R17 is a safe swap for 335/30R18 by the usual ±3% rule: the diameter differs by +0.47%.
What's the difference between 335/30R18 and 255/45R17?
255/45R17 is 0.12" taller and 80 mm narrower; the sidewall is +0.56". At an indicated 60 mph you'd actually be doing 60.3 mph.
Will 255/45R17 fit on 335/30R18 wheels?
No — 335/30R18 needs a 18" wheel and 255/45R17 a 17" wheel. This is a plus/minus-size swap that changes wheels too.