Date: 3 Mar 2005 12:36:35 -0800 From: "R. Frist" <fristnospamt.edu> Subject: Re: Saab 9-3: What octane to tank?
Just a thought: Is it not true that in order for the knock sensor to work it must sense a knock? If so, it follows that running lower octane in a turbo must cause a little more wear and tear than high octane fuel. I suppose it depends on how often the knock sensor lets the ignition and boost advance until another knock is detected. Another consideration may be carbon deposits. A friend of mine has a Cadillac with signs "Use only premium fuel" all over it. He claims that using premium is a waste and has only used 87 for the last 10,000 miles. He now complains that the car keeps running on roughly after turning off the ignition. Granted, the Cadillac is not a turbo and has a higher compression ratio then turbo engines at atmospheric pressure. Maybe this is not a problem with turbo engines. Does anyone have any data?