78 SC... 17mpg???
08-05-2008, 08:06 PM
#34
Team Owner
Now that's two of you with this handy tip. I shoulda posted a question about this last summer when I got the car!!! Gassing my car up for 45 minutes, squeeze, click, squeeze, click, squeeze, click, curse curse curse....
Drive spiritedly, but fuel gently!
Hey, in deference to Iceman, when I rotate the gas pump 180 degrees...I'll do it counter clockwise!
Brent
Drive spiritedly, but fuel gently!
Hey, in deference to Iceman, when I rotate the gas pump 180 degrees...I'll do it counter clockwise!
Brent
that was actually pretty good. But more seriously I don't rotate it after it is in. I flip the hoseover and insert it this way .. she likes it better this way ...... BABY !!!!
08-06-2008, 11:23 AM
#35
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The 1978 911SC owners manual recommends "Regular with at least 91 octane RON (87 CLC rating on fuel pumps in USA)". The CLC octane numbering system shown on US pumps is typically 4 numbers lower than the RON rating, being an average of the "Research Octane Number" and the "Motor Octane Number".
Paul Frere confirms this in his book, explaining the compression ratio was dropped
"mainly to lower the octane requirement of the engine in view of the reduction of the lead content which, at the time, was soon to be made compulsory in Germany. It had been feared that the octane rating of 98 might be reduced so the engines were all tuned to run on Regular fuel of 91 octane rating. ..for the 1981 model 911 SC, known internally ast 911 SC, B-series, the compression ratio was raised back to 9.8:1 with 98 octane fuel mandatory." (Porsche 911 Story 7th ed. p76)
Compression ratio of the 78 SC engine is 8.5:1.
Such are the wonderful anachronisms of owning and operating a car from the '70s. Of course you have the final decision on what gas you put in your car.
Paul Frere confirms this in his book, explaining the compression ratio was dropped
"mainly to lower the octane requirement of the engine in view of the reduction of the lead content which, at the time, was soon to be made compulsory in Germany. It had been feared that the octane rating of 98 might be reduced so the engines were all tuned to run on Regular fuel of 91 octane rating. ..for the 1981 model 911 SC, known internally ast 911 SC, B-series, the compression ratio was raised back to 9.8:1 with 98 octane fuel mandatory." (Porsche 911 Story 7th ed. p76)
Compression ratio of the 78 SC engine is 8.5:1.
Such are the wonderful anachronisms of owning and operating a car from the '70s. Of course you have the final decision on what gas you put in your car.
