Comparison

225/55 R18 vs 245/40 R19

245/40 R19 is a plus-1 alternative to 225/55 R18 — the bigger wheel shows through a thinner sidewall. This sizing approach 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. The wider section adds contact patch and lateral stability, while eating into fender and suspension clearance. The larger wheel shows more of the brake hardware and tightens up the wheel-gap look. Diameter delta falls in the cautious 3–5% range, where speedometer recalibration and a careful clearance check are worth doing.

TakeA solid pick for drivers chasing a more aggressive stance without abandoning OEM rolling diameter.

Quick math: 245/40 R19 is 26.1 mm shorter than 225/55 R18, shifting the speedometer by -3.70%.

Current Tire

225/55R18

New Tire

245/40R19
225/55 R18
245/40 R19

Ground line · scaled comparison

Slight Difference

Within ±5% — usable, recalibration recommended

Diameter change

-26.1 mm

-3.70%

Speedometer at 100

96.3 km/h

-3.70% error

Ground clearance

-13.1 mm

ride height delta

Sidewall change

-25.8 mm

revs/km: 469.1

Permalink for this comparison:

/compare/225-55-r18-vs-245-40-r19

Detailed comparison

Metric225/55 R18245/40 R19Difference
Overall diameter704.7 mm678.6 mm-26.1 mm (-3.70%)
Sidewall height123.8 mm98.0 mm-25.8 mm
Circumference2.214 m2.132 m-82.0 mm
Revs / km451.7469.1+17.4
Ground clearancereference-13.1 mm-13.1 mm
Speedometer @ 100 km/h100.0 km/h96.3 km/h-3.70 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 96.3 km/h after switching to 245/40 R19 — a -3.70% 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 -13.1 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

225/55 R18

Back to

245/40 R19

Drivers also compare

Closely-related fitments and plus-size swaps for 225/55 R18 and 245/40 R19.

Related topics

Frequently asked questions