Yeah, I can see this as a big quality problem, or maybe not... My MS6 is stock and doesn't blow smoke so far at 5k miles. If it started to smoke tomorrow, I'd be all kinds of pissed and take it in and insist on repair. We've seen two guys in this thread get new turbos, and quite a few bitchin about it without follow up threads saying whether their problem was fixed or even if they'd been to the dealer at all yet. We've also seen some who say that the dealer's telling them it's normal, and one who seems to be made to jump through hoops verifying oil consumption, maybe in a buildup to be told "Sorry, there's nothing we can do, eh?" So we see the scattering of good and not so good treatment from dealers, which is pretty normal. The far extremes of dealerships actually have to be discarded in terms of figuring out if there's a problem Mazda can and should fix. Finally, (to me) the key to understanding the entire problem is the MS3 owner who reinstalled his stock pipes and the smoking actually went away.
On the one hand, if I were Mazda I'd tell you it should be expected, and recommend turbo upgrade in conjunction with exhaust mods. On the other hand, perhaps if I were Mazda I'd have done a right big exhaust in the first place and spec'd out a turbo with seals that matched. But, that wouldn't allow me to manufacture a car like the MS6/MS3 at the price, then would it? ...and guys would toss on an even bigger set of pipes and I might be facing the same problem anyhow. Of course, if I had three hands, there's the part where it sucks that you can't do basic warranty-safe mods and get more power without looking like a mosquito sprayer, and that hurts Mazdaspeed's rep from a tuning perspective. I would see this as most important, but it would be a tough sell to increase the performance of a part in case someone decided to modify another part of the system.
Bottom line is this: You mod your car, you go outside engineering specs. Exhaust mods on a MS6/MS3 will reduce the turbo seal pressure too far out of spec, and cause oil bypass and smoke. This may be surprising to some, but others, having done research have offered that it shouldn't be. IMO, unless you have a stock exhaust and your turbo leaks, Mazda shouldn't be responsible. If you installed a bigger turbo and blew up your motor because you didn't control the extra boost you wouldn't expect Mazda to cough up a new one. Technically, this is the same thing, and for that reason I have to disagree with the intent of the thread. I don't believe Mazda's seal design is responsible, at least not at this point in time.
Argue that an Evo or Subie wouldn't have this problem, and I say these aren't either one, they're Mazdas. Mod within limits or mod the limiting factors to compensate.
Not knocking the desire to mod, I have a modded 74 Vette. But with every mod I've done, I've taken into consideration the consequences of each, and built or beefed accordingly. I also base my decisions on lessons learned by Vette owners over the years. We're now learning those consequences, and how to base mod decisions in the MS6/MS3.
