At the risk of continuing what was only a marginally interesting thread at its best that is degrading rapidly...

I see references to 3K changes all over the place, including on this board. For example the first thing you often hear about a used car is "changed the oil every 3000 miles" like that is the holy grail of automotive maintenance. This piece of wisdom has quite a following, no? Shoot, there are people on this board who say they use Mobil 1 synthetic and change it at 3K.

One of the supposed concerns about infrequent oil changes is that even if the oil additives don't break down like they used to the oil still gets contaminated with combustion by-products, especially during cold starts, and this stuff needs to be removed by changing the oil.

OTOH there are posts on this board about changing synthetic at 10K, 15K, 25K, pick your high mileage.

And of course there is the recommendation in the manual, which we all now know is 7500 for non-turbo engines. But I've heard that the manufacturers started using longer oil change intervals in order to reduce the cost of scheduled maintenance for the first 30K miles, a number apparently tracked by Consumer Reports-like magazines. And as I said that is the same manual that says you don't need to change tranny fluid.

So whadaya gonna do? There's lots of conflicting info out there about oil change intervals. I come to this board to get real world info and to share experiences of people who know how to take care of Volvos, not marketing stuff from Volvo or Jiffy lube or Amsoil or Slick 50 or STP or whatever. When I read that BMW's engine computer in one particular case decided 18K was a good oil change interval it said a lot toward debunking the 3K "myth", so I posted it. Not that big a deal, I guess it wasn't clear.

Thanks for responding, but if you are arguing with me that 3K miles oil changes are not necessary you are preaching to the choir.

In the meantime via another thread my mind is made up for my next oil change. "John O" (I think it was him, one of Volvo techs) said he uses Amsoil. That works for me. Maybe I should have just asked what he uses in the first place.