Octane Rating Diesel? [Archive] - SaabCentral Forums

: Octane Rating Diesel?

18th August 2004, 07:12 PM
Yeah, I know, stupid statement, but, why is it that there are differences in diesel fuel? My 9-5 3.0 TiD was somewhat sluggish following several fill ups using diesel purchased from my local Sainsbury's supermarket. For no reason except that I had shopped there last weekend, I filled up at Tesco's. The difference is astounding, watch out all you Aero drivers..... But seriously, I always thought that diesel was diesel was diesel, if you know what I mean. Is it possible that the fuel supplied by Sainsbury's is inferior to that provided by Tesco. I experienced a similar situation earlier this year, Shell diesel seems "faster" than some others. Any chemists out there wish to comment.For the record, 70 to 110 (mph, where legal!) comes up in not much more than 10 seconds in 5th... :-??

18th August 2004, 09:38 PM
Strange, because I have read in the manual of the 9-5 3.0 TiD that the cetane number (= self-ignition-capability, this I translated directly out of dutch) should be 45 minimum. Most cars have a cetane number of 49 or 51 (the EN 590 standard).
So the 3.0 TiD should be able to handle diesel with a lower cetane number ( less self-ignition-capability).

Maybe it has nothing to do with this, I think cetane number is only critical when the engine is cold.

If you find out more keep us posted.