Never dismiss the importance of quality tyres for your car; these are, after all, the only parts of the car that actually touch the road! Old and worn tyres can cause drag and resistance when you drive, which results in more wear and tear on your vehicle. They can also cause the car to skid and slide when you brake, which is an obvious hazard to you and other drivers.
On the other hand, new tyres in good repair will allow for better traction and handling, reducing your fuel consumption, and they may even run more quietly than older tyres. When you are ready to replace your car's tyres, note some simple but very important precautions, so you're sure to have a safe vehicle that handles well on the road.
It's never good to have four different brands or models of tyres on your vehicles, as different brands may be the same size, but will still have variations in their tread pattern, weight, and other such details. These variations will cause the tyres to pull against each other, and will also add stress on the car's tie rods, rims, and other parts connected to the wheels and steering.
If you cannot match all four tyres on your vehicle, be sure the two in the back match, and the two in the front also match. This will reduce some drag and resistance and stress on your vehicle.
Also, if you have a front-wheel drive vehicle, make sure the larger, stronger, newer tyres are on the front. These tyres do the bulk of the work in pulling a front-wheel drive vehicle, so they should always be the ones in the best condition. Remember this if you're just replacing two tyres and not all four; keep the older or smaller ones on the back wheels, and install the new or the larger and stronger tyres on the front wheels.
Even if you're buying four new tyres, be sure you have them all balanced. Even the same brand and size of tyres may have some minor weight differences, and your own car's condition can also affect the weight and structure of the tyres. Balancing tyres involves adding tiny weight to one of them, if necessary, so that both tyres on the front and both tyres on the back are weighted and aligned the same. This will reduce drag and resistance, and also reduce any excess wear and tear on the tie rods, shocks, struts, and other such parts.
Keep these ideas in mind as you look at tyre sales.