<VV> FW: How often do you change your oil?

[Joel McGregor]

Like pretty much everything the government does all you get is a bunch of hype and no facts.  Where are the oil studies that show that a 10k mile change interval is acceptable?  Where are the studies that show pistons no longer expand since they make them out of something other than cast iron?  I've read actual studies on oil in motorcycles that gave real data that indicated 1500 miles was too long for several of the oils tested.  I've never seen a cast iron piston myself and I've seen some pretty old pistons.  My wife's CTS recommends not changing the transmission fluid at all.  We bought the car with 6k on it and the trans fluid was like black water.  I change my Mobil1 and transmission fluid at 3k and that doesn't seem to be overkill based on how nasty and thin the oil appears when I drain it.  I know that isn't very scientific but I haven't worn out any engines lately.  I had a friend with a new Honda about 15 years ago that had a 15k oil change interval.  I told her that was nuts but she insisted that Honda knew more than me.  That engine was smoking by 65k.  I guess the auto manufacturers won that battle over those big oil nasties.  When's the last time you saw a study on resources wasted on replacing cars instead of driving old ones?
Joel McGregor

Or, it's a conspiracy to rid the roads of cars which are gonna be
wearing out faster.  ;)


...wtf?  When was the last time a car made in this country had iron
pistons?   And iron expanding more than aluminum?