CHECK FOR DAMAGE.
Regularly examine your tyres for bumps, bulges, cuts, cracks, tread wear and for any foreign objects embedded in your tyres. Look at your sidewalls, for deeply scuffed or worn areas and small slits or holes. If in doubt, have it checked by an MTA general repairer.
CHECK YOUR TREAD
Most car tyres have tread-wear indicators built into them. These bars of hard rubber are normally difficult to see in a new tyre but appear across treads that have been worn down to 1.5mm of the tyre tread base (the legal limit). If these indicators appear in two or three different places, less than 120 degrees apart on the circumference of the tyre, replace the tyre. Snow or winter tyres legally must have 4.0mm of tread depth and be a matched set. Your tyres are a crucial part of keeping your vehicle safe to drive – and, like brake pads, they eventually wear out and need replacing. Think about maintenance as an ongoing operating cost; budgeting for this will keep surprises manageable and give you more options.
CHECK TYRE PRESSURE
Correct tyre pressure is vital for balanced braking, maximum grip and maximum tyre life – and can improve fuel economy. Recommended pressure varies for each vehicle, and according to load or speed; check with your vehicle handbook, or online. Also, make sure your car is cold when you check tyre pressure to ensure the tyres haven’t expanded after use.
HOW DO YOU CHECK TYRE PRESSURE?
You can use a tyre gauge to check your tyre pressure at the majority of service stations. The recommended cold tyre pressure is usually given on the tyre information label frequently found on the front or rear doorjamb on the driver’s side, in the centre console, on the inside of the glovebox lid or the vehicle handbook.
WHY ARE UNDER- AND OVERINFLATED TYRES A PROBLEM?
Underinflated tyres wear out faster, create excessive heat, increase fuel consumption, and make your car harder to handle. Overinflated tyres are more easily damaged by road debris, wear out faster and may make the car unstable and unsafe to handle. If your tyres don’t show these indicators and you think that they may be worn below the legal limit, visit your tyre professional for a free tread depth check. Also, pay attention to leaks – if you keep losing air in your tyres, have your local service station or tyre shop check them.
HOW TO READ YOUR TREADS
Both shoulders worn
The culprit: Under-inflation. Remedy: Add more air; check for leaks
Centre ribs or blocks worn
The culprit: Over-inflation. Remedy: Reduce pressure to the manufacturer’s specifications.
One-sided wear
The culprit: Poor alignment. Remedy: Have wheels aligned.
Treads worn unevenly, with bald spots, cups, or scallops
The culprit: Wheel imbalance and/or poor alignment. Remedy: Have wheels balanced and aligned.
Erratically spaced bald spots
The culprit: Wheel imbalance or worn shock absorbers. Remedy: Have wheels balanced or replace shock absorbers.
Edges of front tyres only worn
The culprit: Taking corners too fast or winding roads. Remedy: Slow down and use alternative routes if possible.
Saw-toothed wear pattern
The culprit: Poor alignment. Remedy: Have wheels aligned.
Whining, thumping, and other unusual noises
The culprit: Irregular tyre wear, poor alignment, or worn shock absorbers. Remedy: Have wheels aligned or buy new tyres or shock absorbers.
Squealing on corners
The culprit: Poor alignment or underinflation, Remedy: Check wear and inflation pressures.
This article is taken from: https://www.mta.org.nz/radiatorgo/motoring-tips/tyre-checklist/