Comparison

235/35 R19 vs 265/40 R18

Minus-sizing from 235/35 R19 to 265/40 R18 pairs a smaller 18-inch wheel with more rubber between the rim and road. This alternative fitment noticeably changes overall diameter compared to OEM.

The speedometer error is noticeable and may warrant a recalibration if you rely on indicated speed. The taller sidewall adds cushioning over potholes and rougher roads, with a softer overall ride. The wider section adds contact patch and lateral stability, while eating into fender and suspension clearance. The smaller wheel is also lighter and easier to find affordable winter rubber for. Diameter delta falls in the cautious 3–5% range, where speedometer recalibration and a careful clearance check are worth doing.

TakeTypical choice for a dedicated winter or off-road setup where extra sidewall pays off.

Quick math: 265/40 R18 is 22.1 mm taller than 235/35 R19, shifting the speedometer by +3.42%.

Current Tire

235/35R19

New Tire

265/40R18
235/35 R19
265/40 R18

Ground line · scaled comparison

Slight Difference

Within ±5% — usable, recalibration recommended

Diameter change

+22.1 mm

3.42%

Speedometer at 100

103.4 km/h

+3.42% error

Ground clearance

+11.1 mm

ride height delta

Sidewall change

+23.8 mm

revs/km: 475.7

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Detailed comparison

Metric235/35 R19265/40 R18Difference
Overall diameter647.1 mm669.2 mm+22.1 mm (+3.42%)
Sidewall height82.3 mm106.0 mm+23.8 mm
Circumference2.033 m2.102 m+69.4 mm
Revs / km491.9475.7-16.2
Ground clearancereference+11.1 mm+11.1 mm
Speedometer @ 100 km/h100.0 km/h103.4 km/h+3.42 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 103.4 km/h after switching to 265/40 R18 — a +3.42% 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 +11.1 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

235/35 R19

Back to

265/40 R18

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