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Old 07-26-2002, 10:02 AM
Ron Brooks Ron Brooks is offline
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Join Date: Jul 2002
Location: Stony Brook, NY
Posts: 160
Michael 2 quick questions

My first question can be answered simply enough if anyone has an owners' manual. I have no problem using premium gas but I'm wondering if there is confusion over the octane requirements.

My last car was an '83 944. The owner's manual stated it required premium fuel with the minumim octane rating of 91. But, it did not use the R+M/2 method of calculating octane. It used the old method of calculating octane. The old method resulted in numbers 4 points higher than the research method used today as an industry standard. The end result is that the 944 required 87 minimum octane from today's pumps (which was the old 91). Now, the later 944 models raised compression and did require 'real' 91 octane from today's pumps. My '83 944 has a compression ratio of 9.5:1 The MB 1990 3 liter engine has a 9.2:1 ratio so I find it hard to believe that 9.2:1 requires a higher octane rating than a 9.5:1 engine.

SO, does the give the octane requirements for the 3 liter engine and the method used to calculate it? The manuals usually list minimum requirements and the method used for calculation as common info.

My second question is, do you know a website that lists the features in the SE or SEL?

OK, two more: how have you found ownership so far? and How many miles have you put on?


Ron B.
Ron Brooks
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