Funny thing about the latest Asian compact sedan to reach North America: Punch the throttle after stopping at a traffic signal and, unless you meter the pedal willfully, the tires will squeal and tread will peel onto pavement. A compact economy car has enough spunk in a stoplight derby to leave rubber? It does when it's the new Sephia by Korean automaker Kia. Kia Sephia (pronounced kee-ya sehfee-ya) is strengthened this year in a tight structural package with a twin-cam four-cylinder engine producing 125 horsepower. Good gear ratios in the manual transmission and engine torque slanted to excel at lower speeds quickens the action. So the Sephia really zips away from a stoplight start. It also acts forcefully at highway speeds, which builds confidence for passing. Recent attention by Kia's engineers to tame engine vibrations and stifle sound from entering Sephia's five-passenger cabin has resulted in an enriched experience for riders and elevated the quality and tone of this car. It no longer feels or sounds like an unsubstantial tin box. Factor in the spark of Sephia's powerplant and some attractive price points skewed for several thousands of dollars below Japanese competitors like the Honda Civic and Toyota Corolla, and the Sephia shines in a crowded field of compacts.