275/40R20 vs 305/35R20 tire size
305/35R20 vs 275/40R20, diameter
-0.9% shorter
- Speedometer
- 60.5 mph
- At a true 60 mph
- Diameter
- 28.41 in
- Was 28.66 in
- Revs per mile
- 710
- Was 704
- 3% guideline
- Within
Car built for 275/40R20, now on 305/35R20.
275/40R20 and 305/35R20
| Measure | 275/40R20 | 305/35R20 | Difference |
|---|---|---|---|
| Width, mm | 275 | 305 | +30 |
| Sidewall, % of width | 40 | 35 | -5 |
| Rim, in | 20 | 20 | 0 |
| Section height, in | 4.33 | 4.20 | -0.13 |
| Diameter, in | 28.66 | 28.41 | -0.26 (-0.9%) |
| Circumference, in | 90.0 | 89.2 | -0.8 |
| Revs per mile | 704 | 710 | +6 (+0.9%) |
Fitting 305/35R20 instead of 275/40R20
Within the usual 3% diameter guideline.
- 30 mm wider. Check rubbing at full lock.
Cars with 275/40R20
Cars with 305/35R20
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