I planed to change 4 tires from 195/55R15 to 195/60R15 this morning. But the garage found one of them was broken, so I have to use one 195/55R15 with other 3 195/60R15. They told me there was no problem use those. But I still worry about the highway safety. I need drive a round trip about 1500km this weekend. Can any expert here solve my puzzle?