Some motorists think of adventure when they see a sport utility vehicle,while others consider them monstrous gas guzzlers. We tested two models that set themselves apart from the rest of the crowd. The Lexus 450h is equipped with an electric engine which operates on its own at speeds up to 40 kilometers per hour. The Porsche Cayenne has a fuel-efficient diesel under the hood. The 240 horsepower Cayenne Diesel starts at 56,859 euros in Germany. The Lexus 450h generates 299 horsepower and starts at 59,690 euros.