The 2.5NA in the Mazda3,
The 2.5NA in the Mazda3, while standard across the line for the latest 3, was previously available as an upgrade in the previous 3. It is also used on multiple vehicles across the Mazda line, including the CX-5, and hardly new. I await a better optional engine in the 3, as otherwise the 2.5NA is kind of vanilla, and gets buzzy in the higher revs.