The Sony/Etak unit seems to be very consistant with the speed indication. It is always a little higher than my vehicals speedometer. As far as I can tell with highway mile markers, it is accurate. John Ferrell 6241 Phillippi Rd Julian NC 27283 Phone: (336)685-9606 Dixie Competition Products NSRCA 479 AMA 4190 W8CCW "My Competition is Not My Enemy" > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body