I'm about to switch to synthetic oil on my 2007 stage 1 STi and have been reading up on the oil issues people seem to be having with modified cars and 5w30 oil. I have been advised by some friends/techs to look into a 5w40 synthetic oil but haven't been able to find any recent UOA on them. I searched but did not see what I was looking for that was newer then a year old.

Does anyone have a UOA on Royal Purple 5w40? I'm also looking for UOA on 5w40 valvoline and even mobil 1. I did find a 5w40 UOA on valvoline but the thread was about a year old lol.

Any thoughts, advise and UOA you all can give me would be appreciated. My 07 is stage 1 for now. But that will change.

No. People hate facts so you're not going to find one. :p

There was a recent Redline 5W40 uoa. I know mikeythejew was running the Synpower 5w40, but I don't think he did a uoa on it.

Maybe you could find one on bitog. I know someone did an RP 5W40 uoa there in a Honda Pilot, but that doesn't help much. :D There are probably more Valvoline fans there than RP fans. FWIW, here are the Product Data Sheets:

http://www.royalpurple.com/motor-oil-pp.html

http://www.valvoline.com/products/Synpower.pdf

They're both ACEA A3 rated, so that's a good thing IMO.

-Dennis

Thanks a lot :) those will help me. I'm leaning towards synpower over rp.

Found the Honda Pilot RP 5W40 UOA with a VOA (http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1016036#Post1016036).
I see by his signature that he's now using Renewable Lubricant's Inc instead of RP.

A Synpower thread on bitog. (http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Board=1&Number=1020020)

-Dennis

try iwsti.com as well