I have a 2002 2.4L Eclipse GS with 192k miles on it. Its got the 5spd manual transmission. So I stripped the hole for the drain plug on the (lower?) oil pan while changing the oil and decided I would drill and tap the hole, from 14mm to 16mm, and install one of those EZ Oil Drain Valves. I...

I just rebuilt my engine and am running the sds system stage 2.5. I got around 1,200 miles on the engine. I'm getting different opinions on when to switch to synthetic oil. When should I change to it?