A dual-scroll turbocharger like the one in the Saturn Sky Red Line and Pontiac Solstice GXP would help the Mazdaspeed 3 in increasing its usable rev range. As you can see in the comparison graph between the 3 and the Sky Red Line, peak numbers are similar, but the shapes of the torque curves tell two very different stories. GM's dual-scroll turbo builds boost much earlier, and has almost reached its torque peak by 2000 rpm. At that speed, the Saturn's 2.0-liter generates 210 lb-ft, compared to the larger Mazda engine's 128. Torque is similar throughout the midrange once the Mazda finally wakes up at 3000. By 6000, Mazda's engine is running out of breath, putting out 138 lb-ft while the smaller GM engine still manages 168.

Punch the accelerator at 3000 rpm in a Mazdaspeed 3 and you'll probably smile, too. But if you compare it to the more sophisticated engines of the other cars here, you may find it lacking the linearity and broad-range power delivery that set apart the merely powerful engines from the truly magnificent.