A lot of factors to consider.
Highway driving would be less than city (stop and go) so would flat terrain driving as opposed to mountain driving. Is it a hybrid vehicle? It would roughly use about 100 gallons of gasoline with your traditional combustion engine.
Air/fuel filter? Timing chain sloppy? Fuel pump?
from unburned fuel in the cylinder
plugged up fuel injector or bad injector itself.
It could.
A 4 cylinder is more fuel efficient than a V6. Less cylinders, better gas mileage.
It could be very bad, it will eventually cook the motor. Gases and fuel keep trying to go into the cylinder making the cylinder have no place to put eventually bending valves or breaking a rod. (neither of which are good thing)
Fuel supply problem, possible plugged fuel filter or fuel pump failure..
yes.
No spark .no fuel.
check for a spark from you r#1 cylinder and if it is fine then it is fuel related. If it's not fine check your distributor cap for wear
There would be a number of reasons why a car might jerk while you are driving. Your fuel filter could be clogged, something might be wrong with your carburetor, or your fuel pump.
The fuel lines connect to a fuel rail that is bolted onto engine. The fuel rail holds the fuel injectors that enter into the intake manifold. The fuel injectors then spray the fuel into the intake manifold by where it meets the cylinder head. On the intake stoke of the cylinder the fuel injector will spray allowing the mist of gas to pass into cylinder via the cylinder head intake port.