While it is always best to have matching tires on a vehicle, it is not always possible due to availability and finances.
When mixing, it is best to do so in pairs to help minimize handling and traction differences. Always try to keep as close as possible to what is on the vehicle.
Some things to consider are:
Keep in mind that the newest tires should be installed on the rear of a vehicle regardless of which wheels drive it. Having the tires with the best traction in the rear keeps the potential for oversteer (rear of vehicle breaking lose) to a minimum.
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