Regarding the 1998 to 2002 Eldos, I read that 1998 & 1999 required Premium gas while the "new" 2000 Eldo made less polution and would not require premium though Cadillac did not get to change the fuel warning on the dash that said premium fuel required as they continued to use the 1999 dash on the 2000. I also read elsewhere that the Eldos required premium until 2001 when fuel was switched to regular. Can anyone advise when the the fuel requirement went from premium to regular for 1998 to 2002. Also, would I be correct to say that the fuel requirements for any specific year (1998 to 2002) would apply to both the ETC and ESC together. Thanks, Wally