Comparison

235/35 R19 vs 255/40 R17

Minus-sizing from 235/35 R19 to 255/40 R17 pairs a smaller 17-inch wheel with more rubber between the rim and road. This tire combination shifts overall diameter slightly from OEM. The speedometer offset is small but measurable; worth keeping in mind if you watch the dash closely. Extra sidewall absorbs impacts more readily — a sensible bias for daily commuting and broken pavement. Diameter change stays inside the conservative ±3% safety window — an OEM-safe fitment on most vehicles.

TakePractical direction for winter wheels, chains, or rougher pavement where cushioning matters.

Quick math: 255/40 R17 is 11.3 mm shorter than 235/35 R19, shifting the speedometer by -1.75%.

Current Tire

235/35R19

New Tire

255/40R17
235/35 R19
255/40 R17

Ground line · scaled comparison

Excellent Fit

Within ±3% — safe for daily driving

Diameter change

-11.3 mm

-1.75%

Speedometer at 100

98.3 km/h

-1.75% error

Ground clearance

-5.6 mm

ride height delta

Sidewall change

+19.8 mm

revs/km: 500.6

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Detailed comparison

Metric235/35 R19255/40 R17Difference
Overall diameter647.1 mm635.8 mm-11.3 mm (-1.75%)
Sidewall height82.3 mm102.0 mm+19.8 mm
Circumference2.033 m1.997 m-35.5 mm
Revs / km491.9500.6+8.7
Ground clearancereference-5.6 mm-5.6 mm
Speedometer @ 100 km/h100.0 km/h98.3 km/h-1.75 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 98.3 km/h after switching to 255/40 R17 — a -1.75% 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 -5.6 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

255/40 R17

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