ever since i got this car, 3200 miles on it now) ive used highest octane gas at national chain stations religiously (few tanks not due to location). anywho, ive ran the tank down to near nothing everytime, filling all the way up after. soo, the sediments really get pushed thru before they collect-sound like a decent theory?

Actually, the fuel is what cools your fuel pump. Running the tank dry can overheat it. You have a fuel filter to look after any sediment.

+1 Don't run your tank dry, you'll be buying an expensive fuel pump replacement some day!

I run it to the light goes on quite often, is that considered riding it until it's empty?

No. that should be fine since there's still 3 gallons or more in the tank.

Usual_suspect has a point.....the fuel keeps the pump cool. If you run the level down too far, then there's little to cool the pump.
C.

It usually isn't a problem until the car gets a bit older, when over time, sediments can drop to the bottom of the tank. If you run the car down to the last bit of gas at that point, the sediments can get pushed through the pump, but even at that point, unless there's not enough gas to lube and cool the pump, not really a problem.

What is a problem is that the sediments then start to clog the fuel filter, which make the fuel pump work much harder. It's the increased strain on the pump because of the back-pressure that can cause premature failure.

This is what I was told way back by an engineer, and it makes sense to me.

IMHO the sediment thing is for old cars. I was parting out my old 1992 Nissan maxima. I pulled the tank to drain the gas. I pulled out 15 gal of super. Now when I looked inside, the tank was perfectly clean. I mean sparkling. ie.. brand new.

I agree running the gas down to fumes is not good for the fuel pump, I don't think there's much sediment to worry about.

This seems to be a common discussion now, how many miles does someone get on one tank of gas, running fuel down to E, why is the fuel door on the passengers side etc. (all linked to "running out of gas"). I think the biggest question I have is why do people let their fuel levels get so low? I'll agree, I'm a bit ****....but I tend to fill up no later than reaching 1/4 or 1/8 of a tank. I have 34K miles on my car and I think I've only had the light come on once. I personally don't think it's worth the risk of 1) getting stuck on the highway due to bad traffic or an accident, thereby using more gas than you thought you would need to make it to you next refill and 2) risk overburdening your fuel pump and 3) I like to try to save $ by only filling at my local gas station, where it's always cheaper than everywhere else. I use my car for work to go to meetings throughout the day sometimes (for example this week). I filled up Tuesday AM at my regularly visited station with 93 octane for $2.40/gallon. I then drove to work, to a meeting in western MA and then back home again (probably used 1/2 a tank)...and I filled back up again, knowing I had to go to a night meeting in NH 80 miles away from my office the next day (Wed.). (I don't like to have to go buy gas somewhere else while I'm on the road, because chances are, I'll be paying $2.55 or higher). I then went to my meeting and on my way home, guess what...I filled up again (because I have to go to yet another meeting today down in CT (Thurs.). I'll admit, I don't usually have this many meetings back to back, so 3 trips in one week is quite a bit, but IMO, well worth it. Just my $0.02.

I'm curious though, as to why people let their light come on every time. Maybe it's not a big deal and I'm just ****...who knows.

I don't think you have to worry about garbage in the tank unless you are filling up at old, el-cheapo gas stations for a long, long period of time. I don't think it's good to run past empty, not because it will hurt the car, but you never know when an emergency may come up and you need to be somewhere fast.