Broke right front sidewall on EP100 yesterday on my 2006 Prius. The 4 tires all had about 27k miles on them (all showing surprisingly little wear and rotated every 5k miles). Was in a bit of a rush, and the tire place I normally go to said EP100 is discontinued and they didn't have my size. With hesitation I bought 1 EP422 to replace the broken EP100. I asked about replacing 2, and the gent said with the amount of wear on my tires, he didn't foresee any problems. Curious, anyone think this is going to cause me problems/grief? The bit of driving I've done so far doesn't exhibit any strange behaviors that I've noticed, but I know it's generally best not to put 1 new tire on with 3 old. Thoughts/advice much appreciated. Thanks all!