Synthetic oil anecdote...

[the_sarge]

Here's one for you. I know a guy who transports medical stuff, usually back n forth between Tampa and Miami. He has over 300K on his Camry and hasn't changed the oil in over 100K miles. He put synthetic in it and changes the filter every 5K. He adds roughly 1 1/2 quarts of new synthetic at each filter change. I'm not sure if I want to go THAT extreme, but it's food for thought....

[Altus]

That sounds a lot like he's got a bypass filter system installed, in addition to the normal filter. With those, they use a toilet paper roll as filtration media - which is why it requires 1.5 liters/quarts of oil to replace what's still in suspension in the paper roll. They filter down to amazingly small - allowing longer times between filter changes, and pretty much elimanate the need for oil changes.

[the_sarge]

You're exactly right. I asked him about it at lunch and that's what he has. I should've guessed there was something else involved.

[redlava]

HA! A friend of mine had a Jeep Wrangler that he owned for three years, never once changed the oil or filter in it. Took it in to be serviced before he traded it in and they said the oil and filter looked fine to them. And it was just regular old standard dinosaur goo oil.