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  1. New Mazda 3 Compression Engine

    Site News & Updates
    Thanks to @USCTrojan4JC, we have learned about a majorly revised engine coming for the Mazda 3 for 2018 (2019 model year)? The article talks about a next generation Mazda 3 then too. Source is: Exclusive: Mazda's new engine boosts fuel efficiency by 30%- Nikkei Asian Review
  2. Compression Ratio and Exhaust Note

    2010-2013 Mazda 3 Engine and Performance
    Does compression ratio affect exhaust note? I have seen a few older Mazda 3 with different cat backs that sound kind of ricey, but seems that the newer ones - specifically the Skyactiv - seem to sound deeper and less crackly... is this due to the higher compression ratio of our Skyactiv...
  3. 6MT "decides" to accelerate when compression braking...

    2010-2013 Mazda 3 Engine and Performance
    So I've got a 2012 Mazda3 Skyactiv 6MT with about 15k miles on it. During the course of our time together I have noticed something slightly distressing - when downshifting into 2nd, the engine rev's sometimes will jump unnaturally. I can attempt to speculate about how maybe the ECU has...
  4. Gas pedal compression

    2010-2013 Mazda 3 & Skyactiv Discussion
    I am still learning the ropes on driving a stick shift and my hardest point is not putting so much pressure on the pedal so I am not over-revving the engine from a stand still into 1st gear. My friend who has been helping me even noticed that it was very sensitive compared to her nissan maxima...
  5. Compression Reduction 13:1 to 12:1

    2010-2013 Mazda 3 & Skyactiv Discussion
    Hi All, Not sure if this should go in the Engine and Performance forum but it didn't seem to fit there. I'm wondering if anyone knows how the compression reduction from 14:1 to 13:1 (CX-5) to 12:1 (Mazda3) is actually achieved? Is there something physically different with the engine like...
  6. 2.5 compression test again..

    2010-2013 Mazda 3 Engine and Performance
    So did a compression test last night, warm engine but colder ambient temps First test 80~° warm engine 130 130 128 130 Last night 54° warm engine 132 133 130 133 Now this is at like 6300ft asl, but still these are really low numbers for 9.7:1 it should be in the 180+ range right? could...
  7. 2.5 Compression test results

    2010-2013 Mazda 3 Engine and Performance
    decided to check my plugs today anyway I did a compression test while I was at it, just wanted a baseline of what the cylinder pressure was. ( I know that cams have alot to do with changing it ) Now the results were interesting.. anyone care to chime in Cylinder 1 : 130 Cylinder 2 : 130...