Having spent too much on suspension, CV axles and now brakes on my 2006 2.5i, I'm going to try RP at next oil change, probably before winter, rather than doing head gaskets sooner.
I haven't measured oil loss (but can at next change), but I have wet head seams and a permanent drip on the filter, as well as occasional spots on the ground. That's with Castrol GTX 5/30 high mileage, and Mobil1 5/30 high mileage.
With about 400 miles after using RP, and having cleaned the heads at the seam using brake cleaner, heads are now wet with oil and there’s a drip on the filter. I conclude RP makes no difference to leaking head gaskets.
@mnussbau 400 miles and you have oil underneath, then I can assume you had a fairly heavy leak to start with and nothing will stop that. Either that or your oil filter gasket is leaking.
I'm still moving forward with it because there is something to it. Neither of my cars use the normal amount of oil. The minor leakage on the head has stopped. It's dry. I don't think it's just because I'm anal about keeping the cars maintained either. The VDC is coming up on 3k miles since I changed it last and I checked it this morning with the Impreza and it's still full. And I run the boost on that one up to 10 psi.