Comparison
255/35 R19 vs 255/45 R18
Switching from 255/35 R19 to 255/45 R18 steps down to a 18-inch wheel — a familiar move for winter and dedicated all-terrain sets. This tire combination 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. Extra sidewall absorbs impacts more readily — a sensible bias for daily commuting and broken pavement. Minus-sizing keeps replacement costs down and opens up a wider range of winter and all-terrain tires. The 3–5% diameter gap puts this in caution territory: doable on many cars, but verify clearance and consider recalibration.
TakeTypical choice for a dedicated winter or off-road setup where extra sidewall pays off.
Quick math: 255/45 R18 is 25.6 mm taller than 255/35 R19, shifting the speedometer by +3.87%.
Current Tire
New Tire
Ground line · scaled comparison
Slight Difference
Within ±5% — usable, recalibration recommended
Diameter change
+25.6 mm
3.87%
Speedometer at 100
103.9 km/h
+3.87% error
Ground clearance
+12.8 mm
ride height delta
Sidewall change
+25.5 mm
revs/km: 463.5
Permalink for this comparison:
/compare/255-35-r19-vs-255-45-r18Detailed comparison
| Metric | 255/35 R19 | 255/45 R18 | Difference |
|---|---|---|---|
| Overall diameter | 661.1 mm | 686.7 mm | +25.6 mm (+3.87%) |
| Sidewall height | 89.3 mm | 114.8 mm | +25.5 mm |
| Circumference | 2.077 m | 2.157 m | +80.4 mm |
| Revs / km | 481.5 | 463.5 | -17.9 |
| Ground clearance | reference | +12.8 mm | +12.8 mm |
| Speedometer @ 100 km/h | 100.0 km/h | 103.9 km/h | +3.87 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 103.9 km/h after switching to 255/45 R18 — a +3.87% 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 +12.8 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
255/35 R19
Back to
255/45 R18
Drivers also compare
Closely-related fitments and plus-size swaps for 255/35 R19 and 255/45 R18.
225/40 R19 vs 255/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 0.23%
225/50 R18 vs 255/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 0.66%
235/50 R18 vs 255/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 0.79%
255/35 R19 vs 265/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 1.06%
245/35 R19 vs 255/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 1.07%
245/45 R18 vs 255/45 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.33%
255/45 R18 vs 275/40 R18
Wider variation on the same rim — more grip, less clearance.
Δ 1.38%
235/40 R19 vs 255/35 R19
Wider variation on the same rim — more grip, less clearance.
Δ 1.42%
Related topics