Jim Davis well cited the classic case for required octane fuel, and by 
that logic, it would appear the lamp oil grade gas will be fully adequate 
in gas VWs.  But a factor I've heard that's hard to evaluate still agrues 
for paying the higher price.  Specically, the "detergent package" added 
to the gas above the cheapest grade has a noticable effect after long 
periods.  The source has a radio Auto show and seems to have lots of 
interesting facts and possibly fiction in his head.  I don't know, just 
thought I'd throw this cloud of dust into the rational discussion before 
I pull up to my diesel pump.

John Wakefield - more iron than I'd care to list.