Originally Posted By: Nickdfresh
This might interest you nyzman:
http://www.bobistheoilguy.com/forums/ubb...616#Post1354532
Looks like M1 5W-30 did a very good job in this guy's MazdaSPEED3...
For those following, please see my response in the thread referenced above.
Also:
1. I've spent dozens of hours looking into lubricant choices for the MS3 (and 2.3 MZR DISI for that matter). Indeed, there is rumor of the factory fill being semi-synth, but no reliable sources for this whatsoever. Besides, we know that semi-synth could mean 1% synth in 99% non-synth anyhow. The factory manual does not specify.
2. This is the first thread where I've read about special non-scuffing additives in the factory fill. I'd love to see a solid source on this. The factory manual does not make mention of it.
3. The old "synth is not recommended for Mazda" rumor indeed only relates to rotaries and has to do with their sensitive apex seals. Again, I have not seen anything to substantiate this claim for other Mazda vehicles.
4. The 2007 and 2008 MS3's also had the 5W-20 vs. 5W-30 issue. As I understand, Mazda was leaning towards 5W-20 to help meet CAFE standards but decided late in the game it would not suffice for turbo longevity. Inquiries to Mazda North America indicate the "correct" specified lubricant is indeed 5W-30.
5. Most of us posting UOA's for this motor use Blackstone or other labs using the open-cup method for testing flash point, from which fuel dilution data is derived (along with viscosity data). This is arguably an unreliable test method. Thus I prefer to look first at wear data, and then at shearing on UOA's I've seen for this engine.
6. I've had very good luck with PP 5W-30 and intend to keep my MS3 for a very long time, knowing that the FI and DISI nature may be weak links from a longevity stand-point, and both of which are tied closely to proper lubrication. Hence, I try to be very objective and thoughtful here and would gladly support a lube that would help me come ahead in the long-term.
Thanks,
Nick
