All cars are "top weighted" in regard to the fuel gauge. That (having 211 miles by 3/4 tank) does not mean that you are going to get 844 miles on your tank !!!

This stems from a practice in the "old days" when car companies intentionally mis-calibrated the fuel tank gauge in new cars so that new car buyers would see their cars go a LONG WAY on that first half tank of fuel and be proud of what great gas mileage they got.

My ex-wife was so fooled by this that she ACTUALLY BELIEVED that cars got better gas mileage when the tank was full; her (false) logic being "if I get 350 miles when the gauge sits at half-tank and then only 600 miles in that tank, then I got 350 miles with the "top half" of gas and only 250 miles with the "bottom half," so my car got better gas mileage in the top half of the tank." It took me a long time to convince her that her thinking was faulty.

My 2007 TCH fuel consumption display is accurate to the gallons pumped/miles in the tank to within about 1.6 MPG, which is pretty close.

As far as "guessing" how many more miles to empty, here's how I do it with the non-NAV version of the car:

1. When the "orange gas tank" comes on, I have about three gallons left in the tank.

I figure the worst I can possibly get is about 3 MPG below what the tank average number shows me. Multiply 3 by that number, and that's how many more miles I figure I can drive before using 17 gallons.

Has yet to fail me......D