SkyActiv vs. The Traditional Fuel Injected Motor

After releasing the CorkSport Mazda 3 SkyActiv Power Series Intake, we received several questions about the differences between the SkyActiv and traditional motors. We are writing this technical post to provide some insights into the differences we have seen while testing and developing new parts for the SkyActiv engine.

“SkyActiv engine” is a phrase from Mazda that denotes their direct injected, high-compression motors. This is a technology similar to how diesel engines run, in that it is direct injected and one of the many reasons the SkyActiv engine is able to get such high gas mileage.

Your average fuel injected motor runs 10.0:1 compression and fuel pressures of around 45psi whereas the SkyActiv engine runs a very high-compression of 14.0:1 and extremely high fuel pressure of up to 3000psi. Most people will think 3000psi is a typo, but I assure you it is not.

The piston pictured to the right shows how different SkyActiv pistons are compared to a conventional motor. It is a much more complex piston shape that includes a cavity in the center where the spark plug fires to provide a heat-loss reduction. Fuel is sprayed at the piston in order to prevent detonation or “knock”, allowing the engine to run leaner while making more power.

Another big difference is that the fuel is dispersed into the air inside the cylinder. A conventional fuel injected motor will mix the fuel and air in the intake manifold or in the intake manifold runners. Because fuel normally acts as a cleaning agent for the valves, this could be seen as a negative for the SkyActiv engine design.

We have all seen the commercials about how the gas cleans your engine. This is true, but when we move the fuel out of the intake manifold and into the cylinders, this benefit no longer exists making it more critical to maintain the engine. Adding a CorkSport SkyActiv intake will help with this by keeping the engine clean of dust and pollutants and the filter can be reused time and time again.

There are many great benefits to both the design and functionality of Mazda’s new SkyActiv engines. In initial testing our CX-5 saw increased torque and almost 40mpg.

We are looking forward to developing many more aftermarket performance parts to support this new technology!


Related SkyActive Parts

21 Replies to “SkyActiv vs. The Traditional Fuel Injected Motor”

  1. Why does the regular 2012 Mazda 3 engine use a different cold air intake pipe assembly, than the skyactiv type? I found, that just by removing the filter housing y pipe and leaving the hole at the side of the filter housing open, I gained a tremendous boost in performance. If you calculate out the diameter of the two orifices, they are just over half the area of the hole at the side of the housing. The regular mazda 3 engine has a much larger diameter cold air intake pipe and maybe converting the skyactiv one may make a big improvement in performance. The present system seems to be starving the engine.

  2. We can only guess what Mazda was up to when the designed the intakes for the Mazda 3 in the standard and skyactiv models. I am guessing it was changed on he Skyactiv to change the sound of the intake to make it quieter.

  3. Is CorkSport thinking of cold air intake for the Skyactiv ??? Or perhaps some sort ofchip or pretty blue ( any color ) engine pulleys

  4. The skyactiv engine seems louder when you first start it when it’s cold then the regular engine!! can any one tell me why?

  5. The engine is louder to heat it up quicker since the engine is smaller. You can google it and get a more detailed description.

  6. I have a 2012 mazda3 skyactive car and I’ve done a full intake system not a short ram a volo chip to increase everything. It has made a huge change to the car in gas miles and all. I’m getting 38mpg in town now and 52 on the hwy. yes it’s true. The sound of the intake and exhaust on the car is amazing not the over grown bumble sound like Hondas and all. What to get the best performance and increase the gas miles too do what I did.

  7. Brandon, I also have a 2012 skyactiv. I have a 2.0L and am looking to get a cold air intake. I know that no one sells it for the skyactiv specifically, but what all did you buy and would it work with the 2.0L?

  8. Will you guys develop after market headers for the first generation skyactiv 2.0 engine? I know that 2012-2013 Mazda 3 skyactiv did not receive the 4-2-1 header due to the limited space behind the engine, but i believe it is something possible to achieve if the design of the header is compact enough.

  9. i have a 14′ mazda 3 2.0 and can’t find a suitable ram air because of a air box mounted sensor. did you know they used a 2 to 1 race header on the new sky active sweet engineering

  10. Well i have a 2013 mazda 3 2.0l. What i did and it wasnt difficult and relitivly non expincive was i completely took out the air box snorkel and made some room. I went out and bought an intercooler for a turbo, front mount. Got some pipeing. Attached the inner cooler between the bumper and the raditor then i ran the piping from the throttle body then drilled out a hole for the air flow sensor. It is required ur car wont start without it… i tried lol. Then on the opposite side of the innercooler i ran piping then attached a cheepo spector cone filter. This is time consuming but really worth it

  11. That way too much time consuming check out my instagram mz3pastkunana and u we’ll see how I did. My cai with a velocity filter and safe measures I put on a by pass filter all my pipping is 2 and half inches wide all I used was an adapter for sensor for mazda6 and drilled new holes to match the pattern on my sensor and and high adapters and some of my unused intake piping cuttem up and have my cai velocity filter facing out on my driver side fog light area but I removed my fog light cover to expose my filter but never fear I have a really nice n big bypass filter to prevent water from entering…

  12. HELLO,
    I have a 2015 mazda 3 2.0l and i just bought the short ram intake. can you tell me if it will affect my car in any negative way?
    will i gaIn mpg also?
    and the guy at the dealer told me that if i change the intake i will need to change the exhaust system because the engine is tune in a particular way with the stock intake? IS THERE ANY TRUE TO THAT

  13. It retards ignition timing and ups rpm to force the cat to heat up to pass cold start emissions standards. It does this every cold start for 25 seconds

  14. I have put the Corksport SRI on my 2012 Mazda 3 skyactiv and just did a 400 mile drive. It drastically improved my MPGs. I got an average of 47.3 mpg on my trip. The best I have ever gotten.

  15. Hi guys,

    I see it’s been a bit since any more comments. Hopefully I can stir an answer here.

    I have a 2013 mazda 3 with the skyactiv engine, i’m not trying to go crazy with it, but i would like to improve what I can and the great gas mileage I see people have been getting is awesome. Could someone fill me in on what I should be looking at to improve power and mileage, or one of the two if thats necessary.

    Not familiar with cars too much, trying to understand what I can, hopefully someone from Corksport can help, i see you guys in the forums mentioned a bunch!


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