Comparison
235/35 R19 vs 245/45 R18
Minus-sizing from 235/35 R19 to 245/45 R18 pairs a smaller 18-inch wheel with more rubber between the rim and road. This setup swings rolling diameter far enough to feel on the road. The speedometer error is noticeable and may warrant a recalibration if you rely on indicated speed. More sidewall typically improves comfort and curb protection, especially on city streets. Diameter delta falls in the cautious 3–5% range, where speedometer recalibration and a careful clearance check are worth doing.
TakePractical direction for winter wheels, chains, or rougher pavement where cushioning matters.
Quick math: 245/45 R18 is 30.6 mm taller than 235/35 R19, shifting the speedometer by +4.73%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
+30.6 mm
4.73%
Speedometer at 100
104.7 km/h
+4.73% error
Ground clearance
+15.3 mm
ride height delta
Sidewall change
+28.0 mm
revs/km: 469.7
Permalink for this comparison:
/compare/235-35-r19-vs-245-45-r18Detailed comparison
| Metric | 235/35 R19 | 245/45 R18 | Difference |
|---|---|---|---|
| Overall diameter | 647.1 mm | 677.7 mm | +30.6 mm (+4.73%) |
| Sidewall height | 82.3 mm | 110.3 mm | +28.0 mm |
| Circumference | 2.033 m | 2.129 m | +96.1 mm |
| Revs / km | 491.9 | 469.7 | -22.2 |
| Ground clearance | reference | +15.3 mm | +15.3 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 104.7 km/h | +4.73 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 104.7 km/h after switching to 245/45 R18 — a +4.73% 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 +15.3 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
235/35 R19
Back to
245/45 R18
Drivers also compare
Closely-related fitments and plus-size swaps for 235/35 R19 and 245/45 R18.
245/45 R18 vs 275/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 0.07%
225/50 R18 vs 245/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 0.66%
235/35 R19 vs 245/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 1.08%
225/35 R19 vs 235/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 1.09%
245/45 R18 vs 265/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.25%
245/45 R18 vs 255/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.33%
235/45 R18 vs 245/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.35%
235/50 R18 vs 245/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 2.09%
Related topics