Auto Parts: Fuel Digital Display, fuel gauge, digital displays

Question
I want to know a few stuff regarding the project im workin on...
1) There is Analog Fuel Gauge in all Cars, why not Digital?
2) What is the problem with using Digital displays instead of analog?
3) Is it possible to know the distance yet to travel with the amount of fuel
present in the tank?
4) why is the above pt 3 not implemented in all the vehicles as it is useful for
the customers?
Looking forward for your reply as it would be of great help.
Thank you.

Answer
Things have not gone completely digital yet due to cost.  This is the biggest factor in keeping the prices down on the vehicles we know and love.  Eventually, the "new" technology will drop in price and you'll see it in more vehicles as standard equipment.

As far as your Question #3 goes, refer to my answer above.  Again, I don't see it as impossible to find as standard equipment in the years to come, although I've enjoyed that feature in a few cars I've owned the last several years.  :)