Under the bonnet, the Civic Si features a more powerful version of the 1.5-litre turbocharged direct-injection four-cylinder engine used elsewhere within the Civic range.
The uprated motor develops 153kW of power at 5700rpm, and 260Nm of torque between 2100 and 5000rpm, and is paired with short-throw six-speed manual transmission.
That's an increase of 26kW and 40Nm over the regular 1.5-litre turbo, which cranks out 127kW of power at 5500rpm, and 220Nm of torque between 1700 and 5500rpm.
Naturally these figures pale in comparison to the new Type R hatch, which is endowed with a 235kW/400Nm 2.0-litre turbo driving the front wheels.
In addition to the gutsier engine, the Civic Si has been fitted with a dual-pinion variable ratio electric power steering system, stiffer suspension, more rigid stabiliser bars, solid front and rear compliance bushes, front upper control arms from the Type R, and adaptive dampers.
As standard, the Si rides on 18-inch alloy wheels shod with 235/40 tyres. At the front, the car features 12.3-inch disc brakes. On the inside, the Si is equipped with more heavily bolstered front seats, plenty of red stitching and highlights, and an aluminium shift knob.
Up front, the Si models are distinguished by more aggressive bumpers inspired by the ones used on the new Civic hatchback. At the rear, the Si sedan has larger faux vents and a deck lid spoiler, while the coupe is set apart by a more prominent rear wing.
The Civic Si goes on sale in US from May, with prices expected to be around a grand or two more than the current top-of-the-range Civic models.
It's unknown if Honda Australia plans on unveiling a variant of the new Civic equipped with the more powerful 1.5-litre turbo engine. If such a model comes about, it could help to bridge the performance and price gap between the regular Civic range and the Type R hot hatch.