I do mine at like half intervals. I just replaced my iridiums after about 15K miles. and, you know what, the gaps were all blown out on the ones I pulled.

__________________
For Sale Thread:
http://www.xoutpost.com/classifieds/...ia-bridge.html

2004 X5 3.0i - Sold
1998 328i Convertible (e36) -sold
2004 325xi (e46)- sold

Any questions?: DICE mediabridge|gauge rings|LED Angel Eyes|front door carrier|GT1/DIS/INPA/NCS|bluetooth retrofit|SIRIUS Retrofit|fuel filter|Dorman DISA|Roof Rack Delete|Sunroof drains|AC drains|rear sway bar swap|o2 sensors|VCG|Osram Night Breakers