typo. oops. Anyways, never had any problems. Yes I have sent my oil in for analysis. I got about 50 spare kits at the shop right now, since we send in all the oils from the tractors, implements, and semis once a year.
Anyways, like I said, I put 20,000 miles or better on my cars yearly. I drive in dust, gravel roads, and on snow or ice. I go between 100 degree temperatures in the summer all the way down to -30 or -40 temperatures in the winter. I take care of my car no more than a person should, but I don't skimp out either. My 95 grand prix was sold with 175,000 miles on it. At least 120,000 miles was made with a K&N filter on it. That Filter was put on back when my parents owned it, and probably 60,000 miles before I bought it. I bought it from them and kept it another 4 years and only sold it a year ago. The transmission was getting kinda worn out but the motor was going as strong as when my parents first got it.
If your car has problems... Dont blame it on the components that you and millions of other people put in your car. Blame it on your poor service work, or whatever mistakes you made.