My B200's first oil change is computer scheduled for 23000 kms. Not bad for the fine little paper filter that is used. Normal consumption on any motor should be around .5 to .75 liter per 5000 k. So raise that bonnet often and check your oil level between oil changes. A good synthetic oil filter has many filtering membranes. Our "B" filter does not. Purchase one from the dealer and see what I mean. I change my oil on a more regular basis than the computer recommends. I always use Mobil 1 full synthetic and if you know of a better oil than this, please let me know! Regular car filters remove particles and such but they don't address fuel and water dilution in our oil. Heat brakes down these long chain molecules in our oil and offers less protection as time wears on. Remember when we changed our oil depending on time or mileage,whichever came first? That wasn't a bad idea. Here where I live, north of Montreal, our weather changes from -40 C to +38 C as the seasons change and for me that's too extreme for 20000 to 23000 k of driving. Changing the oil yourself is a simple job, if you can find the oil filter and have a few long extensions and a big socket. Hint , look down from the firewall and' voila,' there it is! Be delicate because it's all plastic!!! Cheers, 