My 1996 850 Turbo has always used a little oil and leaked a little too. I've had to top it off before oil changes....but only about 1/2qt. over 3,000 miles. Not bad for an engine with 200,000 miles on it. Starting in August I started noticing that, not consistently, but every now and then, there would be a large blue cloud in the rear view mirror. At first it was an infrequent occurrence, now it seems to happen more regularly. I am using more oil but the engine still has plenty of pep. It doesn't seem to be fouling the plugs at all. Anyone have any ideas? It's too bad because I love this ride. Help!! Thanks.