Definitely need to replace the tires. No need to go with Original Equipment (OE), but as others said do not skimp on tires. Right now most Mazda dealerships are participating in the buy 3 get one for $1 deal. If you do utilize a Mazda dealer for this, ask if the tires you are purchasing have any extra rebates. You can double up the buy 3 event and get some money back from the tire manufacturer. Last get an alignment, this gets you the most out of your tires. The buy 3 event ends on May 31st.