If you drive your SUV in rough terrain, it is important to know when you need to get a new set of tyres. This is also true if your normal habits doesn’t include too much off road driving. The most probably reason why you would need to change the tyres is due to fact that you have worn out the tyres. This will happen over due course. It will happen faster with low quality tyres and will happen later with solid good tyres from a reputable tyre manufacturer.
The wear is mainly dependent on how much you drive and partly based on your driving habits. If you are an aggressive driver, this will cause an increased wear on the tyres. Also high speeds can cause increased wear, depending if they are designed for high speeds or not.
The way to determine if your tyres are worn out is by checking the remaining tread depth of your tyres. For your SUV summer tyres this should be more than 4 mm. The law requires above 1.6 mm, but for your own safety, you should get ready to change them once they go below 4 mm. You do not want to jeopardise your safety over a few millimetres. A low tread depth can be very dangerous when you have water on the road surface, as you can quickly lose control over your vehicle due to aquaplaning. Also the low tread depth can cause you to lose the grip when you turn, causing the car to skid.
Check the tread depth with a coin that you push into the tread to measure how many millimetres are remaining. Also check the tyres for visual damages, which can be very important if you do a lot of off road driving, where it can be easy to damage the sides of the tyres. When you notice either wear down to low treads or tear on your tyres, then it is time to change your tyres to a new set of tyres.