Changing a single tyre
If your tyres are only minimally worn (the main tread pattern still has maximal groove depth) but you need to change a flat tyre or one damaged by an accident, it is very important that the replacement be the same type of tyre. The new tyre must be the same brand and have the same specifications as the first. It must also have the same speed/load indexes, the same profile/construction, and, of course, the same dimensions.
Changing two tyres
If two tyres have a maximal degree of wear or are damaged, you must replace them with identical or similar tyres. It is very important that you select tyres having the same characteristics as those already mounted on your vehicle.