Please do a search and look through past threads, we go over this a lot.

The transmission of the V6 is slightly less reliable than the I4 and the alternator usually goes between 100 and 150k but only costs about $120 to replace. Both the V6s and the I4s have occaisonal stories about how this or that broke...my V6 has almost 200k on it and I couldn't be happer with the reliability.