A 138-horsepower, 2.0L four-cylinder engine powers all 2008 Hyundai Elantras, and this powerplant is paired with either a five-speed manual or four-speed automatic transmission. The engine has variable valve timing for responsiveness and efficiency; fuel economy rates up to 25 city, 33 highway. The Elantra has a four-wheel independent suspension, with MacPherson struts in front and a multi-link setup with twin-tube shocks in back, along with stabilizer bars both in front and rear for responsive handling. Six air bags are standard on all Elantras, including front seat-mounted side air bags and full-length side-curtain air bags protecting all four outward occupants. Front-seat active head restraints and four-wheel anti-lock disc brakes with electronic brakeforce distribution (EBD) are also standard across the line. Elantra is offered in two different trims, GLS and SE. In addition to the safety equipment, the GLS has standard power windows and locks, remote entry, tilt steering, and a split-folding rear seat, while the sporty-themed SE adds 16-inch alloy wheels, a trip computer, a telescoping steering wheel with audio controls, air conditioning, and cruise control. Option packages including a CD player, sunroof, cruise control, and fog lights can bring more luxury to the base GLS. Option packages on the SE add heated seats, a sunroof, and leather seating.