i have a 1.8t and the turbo is bad, i know it has a k01 turbo, but was wonder can i put a k03 or a k04 as a replacement with out alot of trouble. or what turbo would be better for that engine and where could i fine one for a good price. i also wanted to know if using royal purple syhthetic oil be the best for this egein or would another brand be better?