2012 Jeep Wrangler to Moab: Now That's A Linear Fuel Gauge
March 29, 2012
Once you clear Tejon pass, the run up California's Interstate 5 between LA and San Francisco is mostly straight and entirely dull. You pretty much head north and set the cruise, then settle in and pass the time while the odometer rolls up and the fuel gauge sinks down.
Most such gauges are hopelessly non-linear. The majority of cars I've owned seemed to stay bolted near "F" for the first hunderd miles and then plummet before hanging out near E for awhile. Not so in our 2012 Jeep Wrangler.
Here I'm at the half-tank mark -- it may look a shade low but the needle is actually dead-nuts on the line with my eye square with the gauge. At this point the trip meter and distance to empty (DTE) meter read more or less the same. The number of miles I've come equaled the number of miles I could still go, which is what every geeky engineer like me wants to see when the gauge reads half full (or half empty.)
It gets better. Said linerarity (or accuracy, or truthfulness -- whatever you want to call it) was still in play at a quarter tank. 79 miles is exactly one fourth of the total you get when you add DTE to the trip odometer reading.
The low fuel warning came on at 1/8th of a tank, and those numbers worked out, too.
Of course it did help that I spent the entire tank on cruise control over flat ground. Big throttle fluctuations or changes in engine load, had I made them, would have caused the DTE number to dance around and perhaps plummet as the computer re-evaluated my driving and delivered a more pessimistic prediction that would have screwed up my perfect ratios.
Dan Edmunds, Director of Vehicle Testing @ 11,777 miles