[mmcpeck]

Wow, there are a lot of theories and ideas on here, if I didn't know any better, I would think I was reading a boating forum or one on older cars.

I would agree with everything that Brian R. just said, modern fuel systems have almost no exposure to air and don't vent to the atmosphere. Going below 1/4 tank will do absolutely nothing to your car or fuel system, and also agree that taking your tank to Empty is actually better. In all the years I've worked on cars, I would have to think really hard to think about any rusted fuel tanks I have ever seen. Boats are a different story, I see them a lot on boats, but we're talking a whole different environment.

There is no chance of vapor lock in a modern pressurized fuel system, and fuel injection doesn't run off gravity feed from the tank, or mechanical vaccum diaphram fuel pump, so extra fuel is not helping anything run better.

Cars are made now to be almost idiot proof, if the average person had to worry about any of these issues, or even know what they were, you'd need to give a course in owning a car.

Change you rfilter every 30K miles and use a fuel additive every now and then and you will fine for the life of the car, no matter when you fill or how empty you let it get. And I can confidently say you will never have a rust problem in your fuel tank.