Dude, get down off your high horse. You've obviously got some kind of grudge against dealerships (I'm guessing one has rubbed you up the wrong way in the past), the average corner mechanic is just as likely to use poor quality oil if not more, as they are less likely to have a multi-million dollar contract with a big-name oil company (I believe Toyota uses Castrol for instance, not Joe Bloggs Motor Oil). Dealerships aren't this big bad enemy like you make them out to believe, thousands of people get their car serviced by dealerships every single day without any problems (yes there are bad ones and good ones, but that is true of every market, and also true of home mechanics as well). Hell, my Corolla was dealer-serviced for the first ~250,000km of it's life and it is still perfectly fine, 363,000km and the engine has never been opened ONCE. If anything, I've probably caused more damage to the health of my car by sometimes being a bit lazy with the servicing (air filter really needs a change for instance, and the oil is a bit overdue).