235/50R19 vs 245/45R19 at a glance
| Measure | 235/50R19 (current) | 245/45R19 (new) | Difference |
|---|---|---|---|
| Overall height | 28.25 in | 27.68 in | −0.57 in (-2.02%) |
| Width | 9.25 in (235 mm) | 9.65 in (245 mm) | +10 mm |
| Sidewall | 4.63 in | 4.34 in | −0.29 in |
| Wheel | 19 in | 19 in | +0 in |
| Circumference | 88.8 in | 87.0 in | −1.8 in |
| Revs per mile | 713.9 | 728.6 | +14.7 |
Verdict: close match
Within the 3% rule of thumb, so the speedometer, gearing and ride height change little. Going from 235/50R19 to 245/45R19 is a 2.0% decrease in overall height (−0.57 in), and the vehicle sits about 0.29 in lower. The tire is 10 mm wider. The 3% rule of thumb comes from Discount Tire and 1010tires; it is not a guarantee of fit.
True speed and odometer
| Speedometer shows | You are really doing | Difference |
|---|---|---|
| 35 mph | 34.3 mph | −0.7 mph |
| 45 mph | 44.1 mph | −0.9 mph |
| 55 mph | 53.9 mph | −1.1 mph |
| 60 mph | 58.8 mph | −1.2 mph |
| 65 mph | 63.7 mph | −1.3 mph |
| 70 mph | 68.6 mph | −1.4 mph |
| 75 mph | 73.5 mph | −1.5 mph |
Odometer: 1,000 indicated miles is 980 real miles, and 10,000 is 9,798.
The math
235/50R19: 19 + 2 × (235 × 50% ÷ 25.4) = 28.25 in. 245/45R19: 19 + 2 × (245 × 45% ÷ 25.4) = 27.68 in. Change = 27.68 ÷ 28.25 − 1 = -2.02%. True speed at 60 = 60 × 27.68 ÷ 28.25 = 58.79 mph.
Check next
- Regear and RPM at cruise for this swap
- Speedometer and odometer correction
- Other sizes within ±3% of 235/50R19
Calculated from the size alone. Real tires vary a little by brand and model, and the loaded radius is a bit smaller. Confirm the wheel width range, clearance, load index and speed rating for your vehicle. See how to read a tire size, the load index chart and the speed rating chart.
Size pages: 235/50R19 · 245/45R19. More swaps: all tire size comparisons.