Date: 6 Sep 2000 18:26:18 -0400 From: Jack B <jacknopsamdoche.net> Subject: Re: How does SID work?
Philip G. Schroeder <schroedpnopsamyette.edu> wrote: > how often, is the DTE (distance to empty) calculated? My fuel gauge > stays on full for the first third or so of a tank and then drops > relatively fast to empty for the rest of the tank. So, the 3/4, half and > 1/4 readings seem meaningless. I wonder if that's the GM influence creeping up. I read several years ago that when Cadillac introduced digital gauges, they received a rash of customer complaints regarding fuel economy. You see, the digital gauge was so accurate that it had one "bar" for each gallon in the tank. It's almost impossible to completely fill a tank with the vapor-recovery hoses... so, about five or six miles after driving away from the pump, the tank would drop below one gallon "gone"... and customers were bewildered to see the gauge drop from "F" so quickly. GM consulted psychologists about the problem, and their "fix" was to put a bit of logic into the gauge. For the first quarter of the tank, the gauge reported 1/4 of the actual consumption. For the second quarter, it was half - so the gauge showed 3/4 when the tank was 1/2 full. After the half-tank mark, the gauge became progressively more "pessimistic" until, at the 1/8 tank level, it was showing "E". The customers were thrilled.