Is premium better for Skyactiv?

[alarmguy]

Originally Posted by PimTac
The Toyota Mazda agreement included Mazda sharing SkyActiv technology to Toyota and in return Mazda got access to Toyota hybrid and battery technology.

The new MTMUS will assemble both Mazda and Toyota vehicles. The bigger benefit for Mazda is Toyota's supply stream.


Thank you for this information. Wow, how ironic, I was just taking a shot at the Toyota compression thing because I remember the Skyactiv was patented and remember someplace, maybe the financial news that it might be licensed.

Great post, thanks for the update.

 

[DBMaster]

Originally Posted by wolf_06
I just filled up with 87 octane at shell today. 87 octane and up to 10% ethanol. Last week was on 91 octane at shell as well, no ethanol here with premium in Canada.

I wonder if ethanol as an impact on skyactive??


I've been using E15 in mine for about a year. It is 88 octane instead of 87. The car "seems" to have a little better launch from a stop, but that is unscientific. It runs fine and the fuel economy seems unchanged.

 

[Ws6]

Originally Posted by BMWTurboDzl
Originally Posted by DBMaster
Originally Posted by BMWTurboDzl
EDIT: Per the Mazda DE (Germany) the fuel requirements for the 2.0 Sky-Active "Super lead-free according to DIN EN 228 (at least 95 RON) suitable for E10"


That would be because the Skyactiv engines sold outside the U.S. have higher compression than the U.S. models. Mazda determined that people in the U.S. would be unwilling to spend the extra money for higher octane fuel in a supposedly "economy car."


Ya, as I mentioned a few posts above, I'm wondering if Mazda modified the compression ratio via software or with parts.

You cannot modify static compression ratios with software, which is what is being quoted here.

 

[circuitsmith]

Originally Posted by JOD
I noticed that the car pulled timing in certain situations, significantly, on 87 octane. ---- So, there is definitely a "difference". Will it impact performance? Yeah, under WOT it will, particularly when IAT's rise.


When I know a summer heat wave is coming I'll sometimes add a half tank of premium to the 87 I normally use.
It helps engine response, and not just at WOT. No difference in MPGs though.

 

[Cdn17Sport6MT]

Originally Posted by Ws6
Originally Posted by BMWTurboDzl
Originally Posted by DBMaster
Originally Posted by BMWTurboDzl
EDIT: Per the Mazda DE (Germany) the fuel requirements for the 2.0 Sky-Active "Super lead-free according to DIN EN 228 (at least 95 RON) suitable for E10"


That would be because the Skyactiv engines sold outside the U.S. have higher compression than the U.S. models. Mazda determined that people in the U.S. would be unwilling to spend the extra money for higher octane fuel in a supposedly "economy car."


Ya, as I mentioned a few posts above, I'm wondering if Mazda modified the compression ratio via software or with parts.

You cannot modify static compression ratios with software, which is what is being quoted here.


Quite right...Mazda did raise the ratio of: "displacement divided by combustion chamber volume (the latter at TDC)" by one point... 13:1 up to 14:1 (I think)...but having said that - Mazda Skyactiv engines can delay intake valve closure quite a bit. So the effective CR can indeed be varied by the PCM.