In the case of a straightforward pushrod V8 like the LS3, tuning for outright high-r.p.m. power will cause the motor to shake at idle like an unbalanced washing machine. If you tune for a smooth idle and more low-r.p.m. torque, then your V8 gets wheezy at higher engine speeds. Most pushrod V8s thus occupy a middle ground, and the SS strikes a logical compromise between refinement and high-revving horsepower.

Fire the ignition and the SS rocks ever so softly from side to side at idle, like a boxer ready to charge from his corner of the ring. At low engine speeds, the car can feel a bit sleepy — an LS3 trait shared with the Camaro SS — and maybe less powerful than its 0-to-60 m.p.h. time, about five seconds, would suggest.

But by 4,000 r.p.m. you feel as if you’ve strapped a chair to a controlled demolition. Passing power is immense, with the 6-speed automatic transmission delivering a quick downshift if your right foot so much as grazes the accelerator.

With a manual transmission, the Pontiac G8 GXP got off the line with slightly more urgency, probably as a function of its 3.70 final drive ratio. The SS, like the GXP with an automatic, uses a taller 3.27 final gear, presumably to salvage some shred of fuel efficiency.

And it’s the barest of threads. The SS’s gas mileage is thoroughly horrible, saddling buyers with a $1,300 gas-guzzler tax. The car’s E.P.A. rating of 14 miles per gallon in the city, and 21 on the highway, makes it a little bit better than a Rolls-Royce Wraith (13 city, 21 highway) and a little bit worse than a 4-wheel-drive Chevy Suburban (15/22). Does this thing have pilot lights in the tailpipes?

The upshot is that your fuel bill is offset by a reasonable base price. The SS starts at $45,770 (including the guzzler tax), and it’s essentially loaded: standard features include high-intensity headlights, a rear-view camera and a full suite of electronic safety aids. This is also the first Chevy with a hands-free self-parking feature. The only options are a sunroof ($900) and a full-size spare tire and wheel ($500). The SS’s main competitor would seem to be the SRT Charger, which checks in at about the same price in no-frills Super Bee trim. On paper they look comparable, but the Charger is a big, extroverted lunkhead. I mean, you can get it painted purple, for goodness’ sake. The Chevy’s buyers might otherwise spend their money on a BMW, whereas the Charger’s buyers might otherwise spend theirs following Motley Crüe on tour for a year.