Under the Quest's hood is a 3.5-liter V6, a similar yet detuned version of the engine Nissan uses in several other models. With 235 horses on tap, there's plenty of power for confident highway passes, though the throttle can be touchy and the Quest feels less energetic than the relatively sporty Honda Odyssey. After a week of driving, including more than 500 miles to and from Las Vegas, we recorded 17.8 mpg (the EPA estimates 21 mpg in mixed driving). Some drivers complained about occasional hard shifts from the five-speed transmission – others never experienced any issues, and except for a few instances of hunting for the appropriate gear, found the tranny's operation to be smooth and seamless.