245/40R18
245 mm across the tread, a sidewall 40% of that — 98 mm — on a 18-inch rim. That puts the whole wheel at 25.7 inches tall.
- Sidewall
- 3.86"
- 98 mm
- Overall
- 25.7"
- 653.2 mm
- Circumference
- 80.8"
- 2.052 m
- Revs per mile
- 784
- per minute at 60 mph
What it needs to sit on
It mounts on a rim between 7" and 9" wide, and the tread follows the rim: roughly 5 mm of section width for every half-inch, so about 235 mm across at the narrow end and 255 mm at the wide one. Written the way lift kits and wheel wells are, it is a 25.7×9.6R18 — tall by wide, in inches.
What goes wrong on this size
30 drivers have filed a complaint. 0 of them ended in a crash, and nobody was hurt. Nobody died.
22 of them name what let go, and it is most often blowout. Bridgestone is named more than any other brand.
| What let go | Complaints |
|---|---|
| blowout | 10 |
| blister | 4 |
| puncture | 3 |
| road hazard | 2 |
| crack | 2 |
| tread separation | 1 |
| not stated | 8 |
Where the wheel is named, 14 of 23 were on the front — the end that steers.
What fits instead
Same 18-inch rim, height within 3%. Past that the speedometer starts lying and things begin to rub.
| Size | Height | Ride height | Speedo reads 60, you do | Compare |
|---|---|---|---|---|
| 225/45R18 | 26.0" +1.0 % | +3.3 mm | 60.6 mph | side by side |
| 235/40R18 | 25.4" -1.2 % | -4.0 mm | 59.3 mph | side by side |
| 255/40R18 | 26.0" +1.2 % | +4.0 mm | 60.7 mph | side by side |
| 265/35R18 | 25.3" -1.6 % | -5.3 mm | 59.0 mph | side by side |
| 235/45R18 | 26.3" +2.4 % | +7.8 mm | 61.4 mph | side by side |
| 225/40R18 | 25.1" -2.4 % | -8.0 mm | 58.5 mph | side by side |
| 265/40R18 | 26.3" +2.4 % | +8.0 mm | 61.5 mph | side by side |
| 255/35R18 | 25.0" -2.7 % | -8.8 mm | 58.4 mph | side by side |
Same height, different rim
Bigger rim, same overall height. Sharper steering, harsher ride, and far less rubber between your wheel and the next pothole.
Tires graded in this size
Longest-lasting tread first. The grade is set by the maker and checked by regulators.
| Tire | Treadwear | Wet grip |
|---|---|---|
| CONTINENTAL ProContact GX | 540 | A |
| CONTINENTAL ProContact TX | 540 | A |
| Granada GRANADA Touring HP | 520 | A |
| Sure Mach 3 R702 | 500 | A |
| Toyo Crusade HP | 500 | A |
| Venezia Strada II | 500 | A |
| JK Tyre UX1 | 480 | A |
| Goodride SA07 | 460 | A |
| Hankook veNtus S1 evo2 (OE) | 440 | A |
| CONTINENTAL ContiSportContact 5 | 420 | AA |
| Falken ZE502 | 420 | A |
| Nexen RADIAL N5000 | 420 | A |
If you fit something taller
A taller tire covers more ground per turn, so the needle reads low and the odometer counts short. Over ten thousand miles on the dial, the last column is what you really drove.
| Fitted instead | Reads 30 | Reads 50 | Reads 70 | Real miles per 10,000 shown |
|---|---|---|---|---|
| 225/45R18 | 30.3 mph | 50.5 mph | 70.7 mph | 10,100 |
| 235/40R18 | 29.6 mph | 49.4 mph | 69.1 mph | 9,878 |
| 255/40R18 | 30.4 mph | 50.6 mph | 70.9 mph | 10,122 |
| 265/35R18 | 29.5 mph | 49.2 mph | 68.9 mph | 9,839 |
| 235/45R18 | 30.7 mph | 51.2 mph | 71.7 mph | 10,237 |