Fuel Supply System: Notes

The E72 has a pressurized fuel tank made of stainless steel with two chambers and a tank capacity of 85 liters. The reasons for introducing the pressurized fuel tank are based on US legislation, which provides very strict limit values for HC emissions.

In a vehicle with a conventional tank, the fuel vapors collect in the carbon canister. While driving, fresh air is sucked through the carbon canister for purging and burned in the engine. In the E72, there are driving situations in which the combustion engine does not run (driving is supported only by the electric machines). This means that in such cases, the fuel vapors could not be guided out of the carbon canister to the combustion engine for burning. Therefore, the pressurized fuel tank is used in the E72 to prevent vapors from exiting the pressurized fuel tank. This pressurized fuel tank is designed for an excess pressure of 350 millibars while stopped and 100 millibars while driving.