I don't know if they've gotten any better in this respect but my friend sold his Jeep Grand Cherokee (ok, i can't spell) because gasoline eating microbes kept destroying his fuel pump (a $600 repair, NOT covered under any warrenty)...
The gas eating microbes story is the no-fooling one that the Chrysler service department gave him when they told him he needed his THIRD fuel pump in about 4 months....
I KNOW, this sounds like I'm making this up, but I promise I'm just not that clever...or funny... (ask my wife)...FWIW, there really ARE gas eating microbes but according to a specialist ( a VERY well respected scientist at a university doing lots of work with the oil companies), it would require a batch of microbes the size of a basketball to generate enough acid (what they excrete) to eat up a fuel pump on a car.
My advice? pass on the Jeep..Get the Nissan.