CHICAGO – The 1.4L, turbocharged 4-cyl. powering the all-new ʼ12 Chevrolet Sonic was designed for “fun, lively motoring,” according to John Buttermore, lead development engineer.

The turbo engine is the performance choice over the naturally aspirated 1.8L that's also offered.

So Buttermore is all smiles at the annual Midwest Automotive Media Assn. fall rally to unveil the industry’s new offerings for ʼ12 when media types note the turbo Sonic's spirited movement away from the stop light.

But, when asked if the little turbo Sonic might be joined in the near future by even livelier renditions, such as an SS version, he adopts a cautious demeanor. “It would take a lot more air going through that engine for an SS, and there is no SS in the works,” Buttermore says, adding, “For 2013, we do have some sportier versions coming, just not an SS.” The GM engineer says a 6-speed automatic transmission will join the 6-speed manual early next year.

Though the automatic is a late addition to the ʼ12 Sonic, he notes it could have been worse.

“Originally, the automatic wasn't coming until 2013,” Buttermore says.