The 2006 Honda Civic Si packs an impressive amount of technology into the drivetrain of what is essentially an economy car. First and foremost is the engine, a small-displacement gem that spins its way to 8,000rpm with a howl befitting the distant cousin of a Formula One contender.
From a 2.0-liter, all-aluminum, in-line four-cylinder configuration, Honda squeezes 197 horsepower and 132 pound-feet of torque using a high-volume intake manifold and iVTEC, which encompasses its full arsenal of computer-controlled variable-valve timing and lift-control programs. These systems maximize efficiency and low-end torque, giving sparkling performance while also maintaining EPA-rated mileage figures of 23mpg in the city and 32mpg on the highway, as well as a LEV-2 CARB emissions rating.
Falling (perhaps deliberately) just short of the revered 100-horsepower/liter figure achieved by its pricier stablemate, the, the 2006 Honda Civic Si is still the more engaging drive of the two. This may have been partially due to the more aggressive rubber found on our Si's 17-inch alloy wheels. We enjoyed our week last summer with the Type-S, but the new Si will certainly cannibalize its sales from below.
What sets the handling of the two apart is the 2006 Honda Civic Si's limited-slip differential (LSD), which gives it a clear advantage in lateral acceleration. The LSD acts to send torque to the front wheel with the most grip, allowing the outside loaded wheel to pull the car through in a turn and avoiding wasteful spinning of the inside wheel, which is traveling a shorter distance. Especially in a powerful front-wheel-drive car, this makes a big difference in cornering feel, and with it, the Civic Si has the edge on both the Type-S and the new Volkswagen GTI. Torque steer from rest in a straight line is evident but not intrusive.
The six-speed manual transmission has well-spaced ratios, and the throws are short, inspiring frequent use. But as we noted after our first drive of the Civic Si a couple of months back, the notchiness we loved in the RSX Type-S gearbox is somehow missing in the Si. It's not enough to detract from the driving experience, but we would enjoy a slightly more direct feel to the shifter.
Another mild annoyance that we didn't notice on the, ahem, aggressive short intro drive was the drive-by-wire throttle's lack of response when getting off the pedal. Rather than dropping as the pedal is released, the revs hold level for a solid second before beginning to fall. In our week's experience, we never quite mastered the rhythm of mellow midrev upshifts. The short throws mean you're into the next gear before the engine falls to where it would have been without the delay; it takes some getting used to. One of our testers also complained of high-pitched valve-train whine becoming tiresome during sustained cruising, but this wasn't noticed by everyone.
The 2006 Honda Civic Si offers the usual standard passive safety features: dual-stage, dual-threshold front air bags; front side air bags with an occupant-position sensor; and side curtain air bags. ABS is standard on the Si's four disc brakes; rear drums are standard on the base-model Civics. The Si gets larger ventilated front discs than the next cheapest EX, at 11.8 inches to 10.3. Electronic brake-force distribution is standard on all Civics.
Front and rear crumple zones help the 2006 Honda Civic Si achieve five-star NHTSA frontal crash ratings. Side crash ratings are not yet available, but side-impact door beams come standard on Civics. Daytime running lights are also standard.
Honda's new-vehicle warranty is good for three years/36,000 miles, with rust-perforation protection extending to five years and unlimited miles.