I just bought a new 05' Trailblazer with the I-6 engine. I understand the oil light will come on when new oil is needed. I have always done my own oil changes. I haven't got a chance to jack up and crawl under the TB. I once glanced under the hood, but I couldn't see the oil filter. My question... where is the oil filter and does anyone know any filter numbers? Also, I'm glad I found out that it takes 7 quarts of oil.