A V8 engine uses 8 cylinders that are connected to the crankcase. The name V comes from the formation of the cylinders as they are in a V shape with 4 cylinders on each side. This type of engine requires more fuel so you want to try to make it as fuel efficient as possible. This is a large engine that is used for large cars and no matter which model you drive you can increase the fuel efficiency.
The first step to improving fuel efficiency is ensuring that your engine is all in working order and very good shape. This means you should properly maintain it and make sure you regularly change the air filter, oil, spark plugs, oil filters and other components. Make sure it is regularly checked as this will make it run at its best. If you have an older carburetor system then you should see about purchasing an aftermarket or original fuel injection unit that is electronic. These electronic systems are much more fuel efficient than the old ones.
If you can you may also want to see about upgrading your exhaust system for a performance version this makes it much easier to get rid of the fumes and your engine will use less gas to expel the exhaust. You may also find that a performance air filter also increases the fuel efficiency as this lets in a greater amount of clean air that help the engine to run properly.
Aerodynamics & Tires
It is also important that your car has the least friction when driving as this will take up more fuel. It is like the car is pushing against something and the way to minimize air friction is to regularly wash and wax your vehicle. There are many other steps you can take to promote better aerodynamics. You also want to make sure the tires are filled properly as low or flat tires make the engine work harder which reduces the fuel efficiency.
You also should try to use cruise control when possible as deceleration and acceleration use more fuel and cruise control keeps you at a constant speed. You also want to accelerate slowly and try to drive the speed limit. The speed limit was set as this is the optimal speed for highway driving.
You also want to avoid using the air conditioning when you can as this greatly taxes the engine. If you do use the air conditioning then at least turn it off when going up tall hills and mountains. If you find that you are going to be idling for some time, such as with stop and go traffic, then it is recommended that you turn off the engine.
It is important that you use the proper fuel. Some V8 engines may require premium fuel. You may find that the engine will run fine on a lower grade of gas but it will not have very good performance and you will not get very good fuel economy. Make sure you use the octane that is specified by the maker.