Drive a car and don't know what tread wear indicator bars are??? You should! So read up!
Tyres are made of a rubber composite along with steel and fabric belts internally to give tyres strength and rigidity. Most of us don't see whats inside the rubber, yet most of us are also completely ignorant to the amount rubber externally, mating the face of the road, called tread. Currently, the legal limit for tread depth of any part of the tyre touching the road in QLD is 1.5mm. To give you a great idea, these tread wear indicator bars are built into the surface of the tread and are usually (on most brands) set at 1.9mm. When the tyre tread comes in contact with or prior to coming in contact with the wear indictor bars, guess what? Time to change your tyres! Another important tip is to look for delamination. You can see on the image above not only are the tyre tread depths almost at the wear indicator bars they are also cracking due to age and often times exacerbated by poor quality rubbers used. Both low tread and delaminating or cracking tyre tread can cause havoc in wet and slippery conditions, it will also drastically change your stopping distance! Be tread aware it may save your life (and prevent a defect notice and fine along the way!) :) Mike, ViewMyCar Mobile Mechanics Sunshine Coast. "Your Local Mobile Mechanics"