I have a 1988 244 Dl M47 that had ran synthetic Ams Oil with the Volvo filter since 75000 and it now has 165000 almost. I have been changing the oil every 2500 miles. I have been told by several people that this is overkill. I'm not sure if they know that it takes me five monts to go 3 thousand miles in my car, so is the oil already broke down by the time it reaces that magic number even though its synthetic? How often do other people change their oil? I also have no plans on ever selling the car, so I willing to change the oil at closer intervals if it means that I can get 400k and hopefully more instead of only 300k out of the engene. I have kind of heard that things start to go down hill at 300k so I'm trying to do everything I can to prevent that. Any suggestions?

Also, how the Volvo fileter compare with the Mann. If there is no difference why would people spen the extra $1.50 for the Volvo one? I did have a Volvo one come with a leak at one time. Still the best filter for the car?
Thanks and Happy Bricking?

If you are still running AMSOIL (or Mobil 1), then a yearly change should be just fine for you, assuming you only put on 10K or less.
If you are using junk oil, then every 6 months should be fine.

If you really want the engine to last another 25 years (to get to 300K at 6K per year), fine. By that time, everything else will probably have crumbled away. To get to 400K will be another another 16 years.

if you want to be absolutely sure that your oil is still good, you should do oil analysis, but that costs money.

personally, i run mobil 1 synthetic. on average, i do only about 7500-9000 miles per year. i change my oil every 6k miles, and the filter every 3k miles. i've been meaning to send in the oil for analysis to be safe, but i have heard from many other people that mobil 1 and amsoil are easily capable of doing over 10,000 miles and still not breaking down.

volvo and mann filters are the same. in other words, volvo buys their filters from mann, and then sticks the volvo label/print on it.
--
Kenric Tam
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'