Update on readings. Filled the tank to the brim and went out. The gauge didn't seem to stay on the full mark for as long as before, although this is a guesstimate. The gauge did in fact for the 1st time since I've owned the car drop below the 1/4 full mark, I filled her back up when the needle hit the top of the red zone. I'm very happy with these results, no more guess work when on the 1/4 full mark. Stu.