My Navigator is a twin-turbocharged 3.5-liter V6 (450 horsepower, 510 lb-ft of torque) with a 10-speed automatic transmission and does 0-60 under 6 seconds. It is very complicated under the hood and I use the dealer to perform the routine services. I did have transmission problems which resulted in Fore replacing the valve-body and all of the servos under warranty. I really want to love this car but if I knew then what I know now I probably would not have bought it. It's a beautiful car - quiet and very well appointed. The sound system is like sitting in Carnegie Hall and the massaging seats are really nice but I have this little niggling feeling in the back of my mind that “…something may go wrong.” It’s a huge rolling software platform and everything is computer controlled with literally thousands of sensors and solid state relays. With any luck, I’ll drive it another ten years and who knows, we may all be driving electrics by then!