The new 911 model began production in 1995, setting new limits in the production of supercars. It is the first 911 turbo to have a permanent all-wheel drive system that has provided greater active safety as well as driving dynamics. This system retained Porsche's typical driving characteristics, and for the first time, the two turbines used in the Porsche gave the engine harmonious and powerful power. This is the latest 911 Turbo to have an air-cooled engine with 408 hp from a relatively small 3.6-liter engine. The 911 Turbo models are highly valued for their wild power, reliability and the fact that they were the last air-cooled 911.