I have an o6 STi and i heard that your not supposed to use synthetic till 36k miles because of break-in... when did it take 36,000 miles for break-in process??? Did i miss something here?

 

around 10k is good enough, but its better to 2 times, when u let all ur old oil out n put synthetic in, then run it for 5 mins, then let it all out again, n put new oil in. its more work, but worth it

 

so, what happens if you don't use the synthetic oil? or not all the time. I mean, they're pretty darn expensive when do it at the dealer...

 

If you want to switch to synthetic, do it whenever you feel like it. Everyone will tell you something different. The consensus is 10-20K miles. If you really want to know how the motor is responding to oil, send a sample of your used oil to a lab for an oil analysis. BTW I switched to redline synthetic after break in (3K or 3750) on my 02 wrx.

 

I switched over to Mobil at 10k.

wimpreza: if you want to save some money, find a local mechanic you trust and supply your own oil/filter. You can get a 5qt bottle of Mobil 1 synth from Wal-Mart for ~$21 and the filter from Subaru is only $9 or so.