The X5 delivers a refined driving experience. Its 3.0-liter turbo six-cylinder, paired to a silky-smooth eight-speed automatic, supplies effortless acceleration and a good 21 mpg overall. In our tests we found the ride to be steady, with handling responsive and secure. The interior is super-quiet and impeccably finished, but the third-row seat is suitable only for kids. BMW's iDrive infotainment system is more intuitive now, but still requires a learning curve. Optional safety systems are comprehensive. A 4.4-liter V8 and a diesel are available. A plug-in hybrid with a 2.0-liter twin-turbo four-cylinder can drive on electric power for short distances. Reliability has dropped to below average.