I think the correlation with oxygenated fuels is a good one.  Here in 
San Diego they went to oxygenating year round at about the same time 
as my odometer died.  I was getting 19-20mpg before and am now getting 
about 16mpg (now that I figured out how to get the odometer working 
again).  The test will be when we go on vacation this summer, when we 
have always gotten 24-25mpg in years past.

Dan Fuller
'90 Carat
'63 Bug Ragtop
'95 BMW 318i conv.