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Sidewall

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.

98.0 mm sidewall653 mm · 25.7"
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

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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

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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 goComplaints
blowout10
blister4
puncture3
road hazard2
crack2
tread separation1
not stated8

Where the wheel is named, 14 of 23 were on the front — the end that steers.

What fits instead

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Same 18-inch rim, height within 3%. Past that the speedometer starts lying and things begin to rub.


SizeHeightRide heightSpeedo reads 60, you doCompare
225/45R1826.0" +1.0 %+3.3 mm60.6 mphside by side
235/40R1825.4" -1.2 %-4.0 mm59.3 mphside by side
255/40R1826.0" +1.2 %+4.0 mm60.7 mphside by side
265/35R1825.3" -1.6 %-5.3 mm59.0 mphside by side
235/45R1826.3" +2.4 %+7.8 mm61.4 mphside by side
225/40R1825.1" -2.4 %-8.0 mm58.5 mphside by side
265/40R1826.3" +2.4 %+8.0 mm61.5 mphside by side
255/35R1825.0" -2.7 %-8.8 mm58.4 mphside 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.


245/35R1986 mm sidewall — 13% less
245/45R17110 mm sidewall — 13% more
215/40R1986 mm sidewall — 12% less
275/40R17110 mm sidewall — 12% more
225/50R17113 mm sidewall — 15% more
275/30R1983 mm sidewall — 16% less

Tires graded in this size

Longest-lasting tread first. The grade is set by the maker and checked by regulators.


TireTreadwearWet grip
CONTINENTAL ProContact GX540A
CONTINENTAL ProContact TX540A
Granada GRANADA Touring HP520A
Sure Mach 3 R702500A
Toyo Crusade HP500A
Venezia Strada II500A
JK Tyre UX1480A
Goodride SA07460A
Hankook veNtus S1 evo2 (OE)440A
CONTINENTAL ContiSportContact 5420AA
Falken ZE502420A
Nexen RADIAL N5000420A

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 insteadReads 30Reads 50Reads 70Real miles per 10,000 shown
225/45R1830.3 mph50.5 mph70.7 mph10,100
235/40R1829.6 mph49.4 mph69.1 mph9,878
255/40R1830.4 mph50.6 mph70.9 mph10,122
265/35R1829.5 mph49.2 mph68.9 mph9,839
235/45R1830.7 mph51.2 mph71.7 mph10,237