see... coyote's site says XFi's were made from 91-94... so whether it's an XFi or not, based on the epa numbers for mpg, it appears as though the 89 gets the same mpg as an XFi model. epa has no listing for an XFi for 89... it does have an XFi (along with base model) for 90-94.
based on the description from
http://gtkgeo.50megs.com/ however, the XFi's were made from 89-94. that said, even though mine isn't branded, it has the all black bumper instead of the two tone. it also has the shift indicator light, which though not listed as a distinguishing feature on either site... i thought was an sign of an XFi model - no?