245/40R19 vs 275/30R20 tire size
275/30R20 vs 245/40R19, diameter
-0.8% shorter
- Speedometer
- 60.5 mph
- At a true 60 mph
- Diameter
- 26.50 in
- Was 26.72 in
- Revs per mile
- 761
- Was 755
- 3% guideline
- Within
Car built for 245/40R19, now on 275/30R20.
245/40R19 and 275/30R20
| Measure | 245/40R19 | 275/30R20 | Difference |
|---|---|---|---|
| Width, mm | 245 | 275 | +30 |
| Sidewall, % of width | 40 | 30 | -10 |
| Rim, in | 19 | 20 | +1 |
| Section height, in | 3.86 | 3.25 | -0.61 |
| Diameter, in | 26.72 | 26.50 | -0.22 (-0.8%) |
| Circumference, in | 83.9 | 83.2 | -0.7 |
| Revs per mile | 755 | 761 | +6 (+0.8%) |
Fitting 275/30R20 instead of 245/40R19
Within the usual 3% diameter guideline.
- Needs 20 in wheels.
- 30 mm wider. Check rubbing at full lock.
- Shorter sidewall: 0.6 in less.
Cars with 245/40R19
Cars with 275/30R20
What this cannot tell you
Diameter within 3% is a common shop guideline, not a maker spec.
Load index, offset and clearance are not in this data.
- Two or more sources agree
- One source
- Model-level or estimate
- Sources differ