Illinois tire law: nobody is checking, and it is still an offence

Illinois is the opposite of Pennsylvania, and the difference trips people up.

No periodic safety inspection exists for a privately owned passenger car. 625 ILCS 5/13-101 lists the vehicle classes that must be submitted for a safety test, and an ordinary commuter car is not among them. The biennial emissions test looks at the emissions system; it does not look at your tires.

Driving below the floor is still an offence. 625 ILCS 5/12-405 sets the legal minimum at 2/32 of an inch, measured in two or more adjacent grooves at three points around the tire. Nobody checks on a schedule. That does not make it legal.

The sale rule is stricter than the driving rule

A tire below 3/32 cannot lawfully be sold in Illinois. A tire between 2/32 and 3/32 is therefore legal to drive on and unlawful to sell — worth knowing if anyone offers you cheap used rubber, because the band where a used tire is worth buying and the band where it is legal to sell barely overlap.

Note the precise boundary: 12-405(e)(1) bars mounting a tire below 2/32. In the 2/32 to 3/32 band the sale ban applies and the mounting ban does not.

Condition, not just depth

12-405 also makes a tire unsafe on condition. A rim strike that leaves a bulge, knot or separation puts the tire outside the law whatever it looks like from outside and whatever the tread depth is. Chicago's pothole complaint curve peaks in March, with February through May carrying just over half the year, so late winter is when this shows up.

Sidewall damage cannot be repaired by anyone. Repair or replace covers the judgement; pothole tire damage in Chicago covers the local version.

What to do about it

Because nothing forces the check, the check has to be yours. Twice a year and after any hard pothole strike: quarter test in the grooves, eyes along both sidewalls. See when to replace tires.

If a tire is finished, we fit the replacement where the car is parked: Chicago, or what it costs.

Questions people ask

• Does Illinois inspect tires? Not on a private passenger car. 13-101 does not list one, and the emissions test does not look at tires.
• Can I be ticketed for bald tires in Illinois? Yes, under 12-405, at 2/32 or below in two or more adjacent grooves.
• Can a shop sell me a used tire at 2.5/32? No. A tire below 3/32 cannot lawfully be sold in Illinois, even though you may lawfully drive on the one already fitted.
• Is a bulge illegal even with good tread? A bulge, knot or separation makes the tire unsafe under 12-405 regardless of depth.