Re: Proper gas for 374 engine

Posted by Owen_Dyneto On 2011/2/26 13:24:52

One thing to keep in mind about those "over 100 octane" pump gasolines of the 60s is that the octane rating was derived by the ASTM "motor" method, and hence the ratings would be different if done by todays average of "motor" plus "research" method.

PS - One of the examples cited in Wikipedia's discussion of various octane methods is "BP Ultimate 102" which had a motor octane # of 93-94, and a research octane # of 102. So by today's R+M/2 method it would have been rated at a bit above 98 octane. The Wikipedia read is a good one if you're interested in that, especially the differences available in different parts of the world, a regional differences in the US.http://en.wikipedia.org/wiki/Octane_rating