The 2014 Chevrolet Sonic continues with the two engines and two transmissions it's offered since launch, which are essentially the same ones used in the Sonic's big brother, the Cruze compact sedan.
The base engine is a 138-horsepower 1.8-liter four-cylinder, which can be paired with either a five-speed manual gearbox or a six-speed automatic. If you're thinking of getting a Sonic with the 1.8, make sure you take it out on the highway. It gets coarse and boomy at higher revs, and can feel tapped out under heavy loads.
The more desirable option is the turbocharged 1.4-liter four, which is more refined and flexible, delivers more torque, and is more fuel-efficient to boot. It elevates the Sonic and makes it feel closer to a premium vehicle, against the rough, econocar character of the 1.8. The smaller engine is also rated at 138 hp, and our only quibble is that throttle response sometimes feels like it lags the input for a fraction of a second.
The 1.4 can be ordered with the same six-speed automatic or a six-speed manual gearbox. While automatics will likely make up the majority for both engines, the manual is actually fun to drive with the smaller engine--it offers precise, direct shift action with pleasingly short throws. And the clutch is smooth and almost impossible to get wrong. The automatic for the engine offers up- and down-shift buttons on the side of the lever, though leaving it in Drive is fine--as long as you know that it may end up shifting more often to stay in the most efficient power zone.
Otherwise, the Sonic holds the road well and has decent feel through its electric power steering, far better than some Asian competitors. About the worst thing we can say about its driving dynamics is that all the Sonics we've driven have braked fine, but have had mushy pedal feel.
Note that the Sonic RS model, while it uses the same 1.4-liter engine and pair of transmissions as any other Sonic (except the base LS) has a lowered and retuned suspension, as well as lower gear ratios. These should give it slightly more acceleration, and its retuned exhaust system certainly makes for a sporty soundtrack--even if the difference in performance is slight at best.