Comparison
245/40 R19 vs 285/35 R20
Going from 245/40 R19 to 285/35 R20 steps up to a 20-inch rim while trimming sidewall to stay near OEM rolling diameter. This tire combination noticeably changes overall diameter compared to OEM.
Indicated speed will drift far enough that recalibration is worth considering. The shorter sidewall gives the tire a firmer, more responsive feel and sharpens steering input. Extra width broadens the footprint for more grip, but check inner liner and strut clearance before fitting. Visually, the bigger wheel fills the arch and gives the car a more aggressive stance. The 3–5% diameter gap puts this in caution territory: doable on many cars, but verify clearance and consider recalibration.
TakeCommon upgrade for sportier handling and a tighter wheel-gap look on the same vehicle.
Quick math: 285/35 R20 is 28.9 mm taller than 245/40 R19, shifting the speedometer by +4.26%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
+28.9 mm
4.26%
Speedometer at 100
104.3 km/h
+4.26% error
Ground clearance
+14.5 mm
ride height delta
Sidewall change
+1.8 mm
revs/km: 449.9
Permalink for this comparison:
/compare/245-40-r19-vs-285-35-r20Detailed comparison
| Metric | 245/40 R19 | 285/35 R20 | Difference |
|---|---|---|---|
| Overall diameter | 678.6 mm | 707.5 mm | +28.9 mm (+4.26%) |
| Sidewall height | 98.0 mm | 99.8 mm | +1.8 mm |
| Circumference | 2.132 m | 2.223 m | +90.8 mm |
| Revs / km | 469.1 | 449.9 | -19.2 |
| Ground clearance | reference | +14.5 mm | +14.5 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 104.3 km/h | +4.26 km/h |
Verdict: warning
Between 3% and 5% — noticeable speedometer drift; recalibration may be advisable.
Speedometer impact
At a true 100 km/h, your dashboard will read 104.3 km/h after switching to 285/35 R20 — a +4.26% offset. Use the speedometer error calculator to recheck for other indicated speeds, and the speedometer error guide for the full background.
Ground clearance change
The new tire's half-diameter changes ride height by +14.5 mm. Small differences are absorbed by suspension travel, but anything beyond ±10 mm can affect headlight aim, fender clearance and bump-stop margin. See the plus-sizing guide before committing.
Back to
245/40 R19
Back to
285/35 R20
Drivers also compare
Closely-related fitments and plus-size swaps for 245/40 R19 and 285/35 R20.
245/40 R20 vs 285/35 R20
Wider variation on the same rim — more grip, less clearance.
Δ 0.50%
245/40 R19 vs 275/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 0.52%
245/40 R19 vs 285/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 0.52%
225/45 R19 vs 245/40 R19
Wider variation on the same rim — more grip, less clearance.
Δ 0.95%
285/35 R20 vs 295/35 R20
Wider variation on the same rim — more grip, less clearance.
Δ 0.99%
275/35 R20 vs 285/35 R20
Wider variation on the same rim — more grip, less clearance.
Δ 1.00%
245/40 R19 vs 255/40 R19
Wider variation on the same rim — more grip, less clearance.
Δ 1.18%
235/40 R19 vs 245/40 R19
Wider variation on the same rim — more grip, less clearance.
Δ 1.19%
Related topics