265/50R19 vs 305/40R20
305/40R20 is a safe swap for 265/50R19 by the usual ±3% rule: the diameter differs by +0.59%.
Speedometer and odometer
With 305/40R20 on a car calibrated for 265/50R19, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.6%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.3 mph |
| 60 mph | 60.4 mph |
| 70 mph | 70.4 mph |
| 80 mph | 80.5 mph |
Other sizes close to 265/50R19
- 265/50R19 vs 235/55R19-0.87%
- 265/50R19 vs 255/50R19-1.34%
- 265/50R19 vs 245/60R18+0.48%
- 265/50R19 vs 245/50R20+0.72%
- 265/50R19 vs 255/45R19-4.75%
- 265/50R19 vs 225/55R19-2.34%
- 265/50R19 vs 235/50R19-4.01%
- 265/50R19 vs 245/55R19+0.60%
- 265/50R19 vs 255/55R19+2.07%
- 265/50R19 vs 265/45R20-0.15%
- 265/50R19 vs 245/50R19-2.68%
- 265/50R19 vs 295/40R20-0.48%
Questions
Can I replace 265/50R19 with 305/40R20?
305/40R20 is a safe swap for 265/50R19 by the usual ±3% rule: the diameter differs by +0.59%.
What's the difference between 265/50R19 and 305/40R20?
305/40R20 is 0.17" taller and 40 mm wider; the sidewall is -0.41". At an indicated 60 mph you'd actually be doing 60.4 mph.
Will 305/40R20 fit on 265/50R19 wheels?
No — 265/50R19 needs a 19" wheel and 305/40R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.