The Tribute's drivetrain consists of a modified 2.5-liter gas engine which works in combination with an electric motor. Power is delivered through a continuously variable automatic transmission. Available in both two and four wheel drive, the Tribute HEV can be driven at speeds up to 25 mph on electric power alone, and regenerative braking helps to recharge the battery in traffic. Standard safety features include four-wheel anti-lock brakes, front, side and curtain airbags, and tire pressure monitoring. For 2009, The Mazda Tribute Hybrid comes standard with traction control, electronic stability control with roll control, daytime running lights, and satellite radio.