Comparison

245/35 R18 vs 255/35 R18

Stepping from 245/35 R18 to 255/35 R18 keeps the 18-inch wheel but widens the section by 10 mm. This swap barely shifts the rolling circumference. Speedometer drift stays small enough that most drivers won't notice it day to day. Extra width broadens the footprint for more grip, but check inner liner and strut clearance before fitting. Overall the swap sits inside the safe ±3% diameter window, so ABS, traction control and gearing behave normally.

TakeReasonable performance-leaning swap as long as fender and suspension clearance check out.

Quick math: 255/35 R18 is 7.0 mm taller than 245/35 R18, shifting the speedometer by +1.11%.

Current Tire

245/35R18

New Tire

255/35R18
245/35 R18
255/35 R18

Ground line · scaled comparison

Excellent Fit

Within ±3% — safe for daily driving

Diameter change

+7.0 mm

1.11%

Speedometer at 100

101.1 km/h

+1.11% error

Ground clearance

+3.5 mm

ride height delta

Sidewall change

+3.5 mm

revs/km: 500.7

Permalink for this comparison:

/compare/245-35-r18-vs-255-35-r18

Detailed comparison

Metric245/35 R18255/35 R18Difference
Overall diameter628.7 mm635.7 mm+7.0 mm (+1.11%)
Sidewall height85.8 mm89.3 mm+3.5 mm
Circumference1.975 m1.997 m+22.0 mm
Revs / km506.3500.7-5.6
Ground clearancereference+3.5 mm+3.5 mm
Speedometer @ 100 km/h100.0 km/h101.1 km/h+1.11 km/h

Verdict: excellent

Within ±3% — speedometer, ABS and traction control should behave normally.

Speedometer impact

At a true 100 km/h, your dashboard will read 101.1 km/h after switching to 255/35 R18 — a +1.11% 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 +3.5 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

245/35 R18

Back to

255/35 R18

Drivers also compare

Closely-related fitments and plus-size swaps for 245/35 R18 and 255/35 R18.

Related topics

Frequently asked questions