I've been using
Castrol Edge, a.k.a., "
German Castrol" in my 2006 Mazdaspeed 6 sedan ever since I found out that "
German Castrol" had it's very own (cult?) thread here in
BITOG!
However, for me it was the
GC 0W-30 weight for all those years...at least up until this July. That's when the dreaded 'smoking turbo' issue hit my
MS6 at ~49,800 miles. Ugh. So I read up on
Mazda's SSP #86 (Special Service Program) for MS3/MS6 smoking turbos...and it instructed dealers to
first change the oil to a full synthetic 40 weight on customer's cars to see if that stopped the turbo from smoking at extended idle.
So...I changed my
Edge 0W-30 out to
Edge 0W-40...just to see what would happen. No luck...still smoked at extended idle like a mosquito abatement truck! So I ended up replacing my OEM 2006 MS6 K04 turbo to a brand new K0422-881 spec'd for a 2013 Mazdaspeed 3, along with some other 'enhancements' (3" catted downpipe, tubular SS header, upgraded top mounted intercooler, HP fuel pump, etc...) Of course that included a new
Cobb Accessport-enabled 'tune' from one of the top tier Mazdaspeed/Focus ST/RS tuners in order to make it all work properly.
Nevertheless, I'm going to keep running the
0W-40 GC until further notice.
(Note: FWIW, I've heard that a lot of MS3 and MS6 owners have switched to
15W-40 Shell Rotella T6 in their engines...especially the folks that have highly modified their
MZR engines. And that is kinda' why I am staying with the
Edge 0W-40 instead of going back to the
0W-30 formulation.
P.S.: I also have the spin-on oil filter conversion for the MZR as well, and am running a
Purolator PureOne #PL20195 filter. So far, so good.
My $0.02 worth...