One of the traditional reasons to downsize is to get better fuel economy. But if you get the 2012 Chevrolet Sonic with the base 1.8-liter engine, its gas mileage ratings, surprisingly, aren't that much better than those of a base, mid-size 2012 Toyota Camry. The 1.4T engine, which is a $700 option in LT and LTZ models, gets better ratings of 29 mpg city, 40 highway, although its ratings with the automatic—not available until later in the year—haven't yet been released.
Even though that places the premium for the 1.4T Sonic to be about $1,400 more than the base Sonic LS, it's a choice that's likely to pay off in the long run, especially if you're planning to keep the car over the long term or if you were already planning to get a better-equipped LT or LTZ. The 1.4T, unlike many turbocharged engines, has been tuned and engineered to run on regular unleaded fuel as well.
On a route that included a mix of city stop-and-go followed by more aggressive driving on winding two-lane roads, we observed that the 1.4T also proves considerably more fuel-efficient in real-world driving. We first managed about 28 mpg in an automatic 1.8-liter Sonic. But in a manual 1.4T in about the same conditions we saw 31 mpg, then 33 mpg in another car, mostly on the highway.