Soichiro Honda's fuel of choice in his youth was high-test sake. He marked his wedding by dancing naked, raced through a life-threatening crash and drove a car filled with geishas off a bridge. (Everyone lived.) Then he founded Honda and found his greatest success breaking convention.

Yet here sits the 2012 Honda Civic Si, a car that defines more conventions than the Oxford Unabridged Dictionary, a design turned in a year late with nary an apology, a vehicle relying on an untold Newtonian law of motion to bring buyers past a Honda dealer every few years like asteroids in need of bigger cupholders. With so many new forces pushing for its buyers, Honda shouldn't have counted so much on inertia.

Let's dispense with the non-Si flavors thusly: If you are one of the 247,000 buyers who buy more Honda Civics than all Volkswagens sold in the U.S. combined, you may need a jewler's loup to notice the changes. I could give you ten paragraphs about the 9% thinner A-pillar for better visibility or the slightly revised engine timing, but the result is the same: The current generation Civic given a lick and a promise.

Here's the fuel economy tale of the tape: Using a tweaked version of the 1.8-liter four-cylinder, in most cases, the Civic will get 28 mpg in the city and 38 mpg on the highway; a HF high-efficiency gas version adds 1 mpg city and 2 mpg on the interstates, while the hybrid — now with lithium-ion batteries — will go 44 mpg city and highway. While the HF barely edges the Hyundai Elantra, it's the lowest-volume model in the lineup; the anodyne versions (from the loaded $23,905 EX-L sedan to the dollar-store quality $15,805 DX that comes without air conditioning or a radio) fall just short.

As with the rest of the new Civics, the Si's two-tiered dash now sports 5-inch LCD screen that offers several displays, from album art for the song playing on the iPod to a Power Meter, which ticks off just how much of the engine's power is at hand. But for those who don't want such details, there's also now a VTEC meter: six lights that act as a mini-tachometer, and another to show when the engine's higher-rev timing has engaged. Yes, Honda saw the faux-Successories posters of "VTEC just kicked in, yo!" and built an Internet meme into its dashboard.

The most important change comes from the enlistment of the 2.4-liter engine from the Acura TSX, retiring the 2-liter in the old model. Top horsepower only rises 4 ponies to 201 hp, reached at the 7,000 RPM summit as Mr. Honda himself often intended. The major modification comes from 170 lb-ft. of torque, a 31 lb-ft boost from the previous version, on call from 1,700 RPM upward.

Combined with the sweetness of the Honda six-speed manual transmission - and let the record reflect that the Civic Si is the only mass-market sedan upon these shores available solely to those who know what a third pedal is for - the Si can spin some sugar. In a tight corners where its all-seasons give out before its multi-link rear suspension, the Civic Si echoes the call-and-response hellraising of Sochiro Honda's youth.

The trouble is outside of those brief moments, the Si has not just turned in late homework, but been kicked out of the honors class. While the steering wheel controls have been tweaked and the seats remain well done, the Civic's dash plastics look bleaker than a conclave of emo kids in a Hallmark store. Stepping into a new Elantra immediately after exiting a new Civic only heightened how nice the Hyundai's interior is.

And power remains a concern. The chief engineer of the 2012 Civic drives a Civic Type R; I asked via a translator what it would take to bring such a model back to the United States. The reply: Doing so would hurt fuel economy, which is our main focus.

Soichiro Honda famously said "the value of life can be measured by how many times your soul has been deeply stirred." The new Civic is slightly better in every dimension, but if you soul is at rest, it lacks sufficient force to put it in motion.