Even from a small pinhole leak that may just drip down on top of a suspension member and evaporate before dripping to the ground??? That would mean thousands of cars that are 15 or 20 years old or older with rusty fuel lines and that are experiancing rough running and low power may have this problem and not even know about it. If it wasn't for my similar experiance with an Eldorado diesel I had, I would never have thought about it and would have wasted money with replacing injectors, the injection pump and who knows how much else!!!