2006 Saab 9-5 Owner's Manual - Page 146

146 Starting and driving than AON 87. However, engine performance will fall slightly and heavy loading and laboring should be avoided. For optimum performance, use the recommended grade of fuel. • The maximum boost pressure is adjusted automatically to the knocking or pinging tendency of the engine. Occasional, short-lived knocking when the engine is under a heavy load is perfectly normal; the extent will depend on the grade of fuel in the tank. • Isolated instances of knocking are more likely to occur with low-octane fuel. This controlled form of knocking, followed by a reduction in the boost pressure, is a sign that the wastegate is functioning and is perfectly safe for the engine. Important considerations for driving The engine-management system in the Saab 9-5 is called Saab Trionic T7. The system manages the ignition, fuel injection and turbo boost pressure. The Trionic T7 system developed by Saab is an intelligent engine-management system designed to achieve optimum drivability under differing driving conditions. The system makes adjustments automatically, for instance, if the car is being driven at altitude (oxygen-deficient air), for different grades of fuel (AON 87-93) and for different load conditions. 1 Starting and driving • Refrain from using full throttle before the engine has warmed up (before needle in mid-range on temperature gauge). • A safety function prevents the engine from revving faster than 6,000 rpm by limiting the induction air. 2 Stopping the engine • Do not rev the engine immediately before switching it off - stop the engine when it is idling. 3 Regulating the boost pressure • One of the advantages of boost pressure regulation is that the engine can also be run safely on gasoline with a lower octane rating, although not lower WARNING If the engine is being run with the car on a rolling road or dynamometer, longer than for a standard state emission inspection, to ensure adequate cooling, air must be blown into the engine compartment and under the car at a rate equivalent to the ram-air effect that would be obtained at the corresponding road speed. NOTICE • If the engine sounds strange there is a fault in the system. Have the car checked without delay by a workshop. We recommend that you contact an authorized Saab dealer. • The use of fuel with too low an octane rating can cause serious engine damage.