Steering feel
Balanced, OEM-style response
A familiar OEM feel — predictable inputs without trade-offs.
Tire size meaning
235/45 R18
What the numbers on a 235/45 R18 tire actually mean — width, sidewall, construction and rim — explained in plain language with real-world driving context.
Direct answer
What does 235/45 R18 mean?
235/45 R18 is a metric tire size: 235 mm wide, a sidewall 45% of that width (106 mm), radial construction, fitted to a 18-inch wheel. Overall diameter ≈ 669 mm.
- 235
- Section width in mm (sidewall to sidewall).
- 45
- Aspect ratio — sidewall is 45% of width (106 mm).
- R
- Radial construction — the modern layered build.
- 18
- Wheel rim diameter in inches (457 mm).
Ø 669 mm · 26.33″ · 476 revs/km
Dimensional breakdown
- Section width
- 235 mm
- Aspect ratio
- 45%
- Sidewall height
- 105.8 mm
- Rim diameter
- 18″ (457.2 mm)
- Overall diameter
- 669 mm
- Circumference
- 2.101 m
- Revs per km
- 476
- Construction
- Radial (R)
What 235/45 R18 feels like on the road
A 235/45 R18 tire is a low-profile sporty tire. With a sidewall of 106 mm, it gives precise turn-in with a reasonable ride compromise — typical for sport sedans and hot hatches.
The 235 mm contact width provides strong dry and wet grip for sport and performance use. Combined with a 18-inch wheel, this size is most commonly found on mid-size sedans, sport trims and modern crossovers.
At highway speed each tire completes about 476 revolutions per kilometre — the figure your speedometer and ABS were calibrated against if 235/45 R18 is the OEM specification.
Common alternatives to 235/45 R18
Sizes within ±3% overall diameter — generally safe swaps for speedometer accuracy and clearance. Click any size to open a full side-by-side comparison.
Driver feel · telemetry
What 235/45 R18 usually feels like
A driver-perspective read on this size — steering, comfort, highway stability and rough-road behavior.
Ride comfort
Comfortable daily ride
A balanced compromise — bumps muted, steering still precise.
Highway stability
Planted at highway speed
Wider contact patch resists crosswinds and tramlining — strong straight-line confidence.
Pothole comfort
Reasonable impact protection
Enough sidewall to protect the rim from typical urban hits.
Sporty vs OEM tone
Balanced everyday character
A factory-style balance between feel, comfort and grip.
Sidewall106 mm
Ø669 mm
Width235 mm
Revs/km476
Related tire sizes for 235/45 R18
Explore neighbouring sizes by intent — similar, wider, lower-profile, OEM-safe, or aggressive. Each link opens a full side-by-side comparison.