Manual: 2011/2012 911

Page: 189

Octane ratings
Octane rating indicates a fuel's ability to resist detonation. Therefore, buying the correct octane gas is important to prevent engine "damage".

The RON octane rating is based on the research method. The CLC (U.S. Cost of Living Council octane rating) or AKI (antiknock index) octane rating usually displayed on U.S. fuel pumps is calculated as research octane number plus motor octane number, divided by 2, that is written as:

The CLC or AKI octane rating is usually lower than the RON rating: For example: 95 RON equals 90 CLC or AKI

Fuels containing ethanol
Do not use any fuels containing more than 10 percent ethanol by volume.

We recommend, however, to change to a different fuel or station if any of the following problems occur with your vehicle:
– Deterioration of driveability and performance.
– Substantially reduced fuel economy.
– Vapor lock and non-start problems, especially at high altitude or at high temperature.
– Engine malfunction or stalling.

Portable Fuel Containers

Transporting Filled Fuel Containers

If the fuel container is damaged in an accident and fuel escapes, it could ignite or explode.

  • Never carry additional fuel in portable containers in your vehicle.
  • Observe the relevant laws which prohibit fuel transport.

Fuel Container Vapor Hazard

Vapors from the fuel are hazardous to health.

  • Do not carry a fuel container in the occupant compartment.

Fuel Evaporation Control
Fuel tank venting
The evaporation chamber and the carbon canister prevent fuel from escaping to the atmosphere at extreme high outside temperatures, when driving abruptly around curves and when the car is parked at an incline or in any other nonlevel position.

Vapor control system and storage
When the fuel tank is filled, vapors are collected in the evaporation chamber by a vent line leading the vapors to the carbon canister where they are stored as long as the engine does not run.

Purge system
When the engine is running, the fuel vapors from the canister will be mixed with fresh air from the ambient air of the canister. This mixture will be directed to the intake air housing by the tank vent line, mixed with the intake air and burned during normal combustion.

Emission Control System
In the interest of clean air
Pollution of our environment has become a problem that is of increasing concern to all of us. We urge you to join us in our efforts for cleaner air in controlling the pollutants emitted from the automobile.

Porsche has developed an emission control system that controls or reduces those parts of the emission that can be harmful to our environment. Your Porsche is equipped with such a system.

Porsche warrants the Emission Control System in your new car under the terms and conditions set forth in the Warranty Booklet.

You, as the owner of the vehicle, have the responsibility to provide regular maintenance service for the vehicle and to keep a record of all maintenance work performed. To facilitate record keeping, have the service performed by authorized Porsche dealers. They have Porsche trained technicians and special tools to provide fast and efficient service.

To assure efficient operation of the Emission Control System:

  • Have your vehicle maintained properly and in accordance with the recommendations described in your Maintenance Booklet.
    Lack of proper maintenance, as well as improper use of the vehicle, will impair the function of the emission control system and could lead to damage.