+4.32%Borderline — noticeable speedometer/odometer error
Speedometer error
With a speedometer calibrated to 295/35R21, fitting 265/45R21 makes it read as follows:
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 41.7 km/h | 25 mph | 26 mph |
| 60 km/h | 62.6 km/h | 37 mph | 39 mph |
| 80 km/h | 83.5 km/h | 50 mph | 52 mph |
| 100 km/h | 104.3 km/h | 62 mph | 65 mph |
| 120 km/h | 125.2 km/h | 75 mph | 78 mph |
Full comparison
295/35R21
Overall diameter739.9 mm · 29.13 in
Section width295 mm · 11.61 in
Sidewall height103.3 mm · 4.06 in
Circumference2324.5 mm · 91.5 in
Revolutions per mile692
Revolutions per km430
265/45R21
Overall diameter771.9 mm · 30.39 in
Section width265 mm · 10.43 in
Sidewall height119.3 mm · 4.69 in
Circumference2425.0 mm · 95.5 in
Revolutions per mile664
Revolutions per km412
+4.32%Borderline — noticeable speedometer/odometer error
Original
Overall diameter739.9 mm · 29.13 in
Sidewall height103.3 mm
Circumference2,324.5 mm
Revolutions / mile692.4
New
Overall diameter771.9 mm · 30.39 in
Sidewall height119.3 mm
Circumference2,425 mm
Revolutions / mile663.6
Speedometer & odometer error
The new tire changes overall diameter by +4.32%. With a speedometer calibrated to the original tire, that same percentage is how far the speedometer and odometer read off — a taller tire means your true speed is higher than indicated and the odometer under-counts distance.
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 41.7 km/h | 25 mph | 26 mph |
| 60 km/h | 62.6 km/h | 37 mph | 39 mph |
| 80 km/h | 83.5 km/h | 50 mph | 52 mph |
| 100 km/h | 104.3 km/h | 62 mph | 65 mph |
| 120 km/h | 125.2 km/h | 75 mph | 78 mph |
See individual specs: 295/35R21 · 265/45R21. A change this size can affect ABS/speed calibration — see wheel-speed codes if a light appears.