I have a 2017 Honda Accord Hybrid. Like to know what each bar indicates on the gas gauge as to how much gas each are worth. It holds 15.8 gallons so I am guessing each bar is 0.8th of a gallon? So almost 1 gallon each bar?

 

I'm not sure, because the bars are moved by the PCM based on the fuel level. If the PCM is programmed linearly, then you are correct. My TSX or old Accord gauge dropped pretty quickly after 1/4 of a tank.

There are few ways to verify. Next time you fill up your tank (assuming your driving is consistent) write down the miles traveled when the gauge drops one light until you get to empty. See if the miles are linear.

You can also fill up your gas tank when the light is at different levels to see how much gas it takes to get full.