That's the problem- seems no two cars are alike. Some are worse than others so when you get used to one it rarely transfers over. One thing I've never come across, though, is a gauge that goes faster through the first half than the second.
Accuracy must be a low, low priority for the mfg's.
I have noticed on the TSX that it's actually linear. It doesn't hang at "F" forever and then move -- it moves steadily downward. I haven't let the fuel-light come on yet -- a little less than 1/4 and it's time to fill. Now, on the 'Teg, I let it go until the light is on for a while. I think the deal is that they don't want people to know how much fuel they actually have so they don't run out of gas. I've rented cars that had the "Miles to Empty" meter and it just goes to "Low Fuel" below 50 miles instead of give a number. I've gotten 75-80 more miles out of it, for example. A rule of thumb: as soon as the light comes on, you have 50 miles left (on the average).