Say a manufacturer builds a small car that doesn’t match the current marketing holy grail of getting EPA highway fuel economy of 40 mpg. What do they do? Well, they introduce a model that does. Maybe it’s a special esoteric fuel economy model. Or maybe the changes go deeper.

Mazda falls into the later camp. Our last Mazda3i sedan was no fuel economy slouch, recording 28 mpg overall in our tests, but the EPA numbers fell below current competitive levels at 25 mpg city/33 mpg highway. To counter that deficiency, the 2012 Mazda3 can be equipped with their new SKYACTIV-G engine for an impressive 28 mpg city/40 mpg highway.

Rather than being a special fuel-efficiency model, this engine is standard on popular mid-level Touring and up-level Grand Touring models equipped with the 2.0-liter four-cylinder and an automatic transmission. (With three trim levels, three engines, three transmissions, and two body styles, the 3 line-up is convoluted at best.) Rather than an automated-manual gearbox or a CVT, SKYACTIV-G comes with a relatively conventional six-speed automatic, boasting one ratio more than the car’s other automatic offerings.

We bought a 3i Touring sedan to see what the new engine brings. It stickered at $20,145 with no options other than wheel locks. Our last Mazda3i was enjoyable to drive, thanks to agile handling, but road noise and a tight rear seat were shortcomings that a new engine probably won’t fix. Hopefully the long braking distances were improved in the update.

Can the 3i rival the Hyundai Elantra at the top of our small car Ratings? We’ll see how the car has improved as we rack up break-in miles and fully test it here at our track.