[RallySnake]

Fuel/water separators are necessary on diesel systems. They get a lot water in the tank and it sinks to the bottom. On 18 wheeler truck's and railroad locomotives, they periodically have to drain the water from the bottom of the fuel tanks because there's no room left for the fuel.

They are not necessary on car's gasoline systems because the water stays mixed with the fuel and the engine can burn the water. They even make water injection systems for more power.

I have given up on aftermarket fuel filters. They are too small. I buy the largest stock type filter I can find in the auto parts store (with 3/8th inch in and out tubes) and mount it before the electric fuel pumps (I always have two). I have had 6 or 7 electric pumps fail over the years before I did this and am tired of buying them. I use another fuel filter between the pumps and the carburetor. I take my fuel tank out of the car about every 10 years and use a garden hose to wash it out. It is amazing how much sand and rust comes out. You would think that branded filling station fuel (I usually use Shell) would be pretty clean, but it's not.