Motor Trend’s Johnny Lieberman brings us the latest in German executive express cars for this episode of Head 2 Head. BMW has been setting the benchmark standard for this class for a long time just like it’s done with the M3 and sport luxury sedans. The M5 has always been the perfect combination of size, comfort, outright speed and agile handling. This year’s model features the first turbocharged engine for the M5 line downsizing from the previous model’s V10 to a 5.5 liter twin turbo V8. The airflow through the heads has been reversed so that the two turbos sit in the valley of the V to improve efficiency. The turbocharged engine provides more power and a lot more torque while using less fuel than the V10. Porsche’s Panamera has been out for a while now and the GTS is their latest trim combination for it. As with many of their other GTS cars, the Panamera features a naturally aspirated engine with a lot of the goodies from the turbo model. Johnny does a good job explaining the nature of the two cars and picking a winner.