My 1998 will tell you how many miles are left.

Also, when I changed out my fuel pump there wasn't any crap in the tank. There was about 130k mies on the pump and the filters were light brown but not plugged.

So before we get into crap in the tank lets first go to the pump.

1. Pumps have filters on them. Look up at the hose bib on the top of the hose.
2. Unless you use dirty gloves when opening your tank........ No dirt should be in there.
3. Don't get gas when a station is filling there tanks........ VERY BAD!
4. Buy good fuel.
5. These are Polyurethane tanks, so no rotting.

If you follow these rules there souldn't be much in the tank other than approx. 10 micron particals. These should get picked up in the 3 huge filters on the trucks pump.

Now everyones got a 25 gallon tank period. It's all OEM made.

Also if you look at the pump the float cannot rise to the top of the tank making a full tank beyond measuring. This is why one can drive 50-100 miles without the fuel gage moving. Same thing applys to the bottom of the tank. The float doesn't touch. Also there is no support so the Polyurethane tank can float lower, because of outside heat, the pump is in the middle and the bottom can flex downward creating different readings in different vehicals. There are only 2 fuel straps located 1/3 from each sides leaving the middle floating. Also the pumps can read different voltage just like a TPS sensor. None are accurate unless tuned. The overhead uses mileage, gas mileage calculations, pump electric output to come up with a figure.....Thats all, a figure and not reallity........Mine comes on at 1/8 a tank constantly.

 

MIght this shed some light on the situation?

 

^ ^

Re-read my last post.

 

1 & 3 - Since pumps have filters, why not get gas when station is filling tanks?

4 - How do I identify good fuel from bad fuel?

 

I always understood the reason for not getting fuel when truck is there, is because that is when all the algae/bacteria/sediment in the bottom of the underground storage tanks is getting stirred up and mixed possibly allowing it to enter the underground pump. Yes it should get caught by their filters, and if not there, by the filters on the filling pump. This maybe an old wives tale but I try not to take chances. Another reason is for some of the smaller stations, the fuel truck makes one more obstacle in the way for a narrow driveway, but the big reason is getting stirred up sediment. You have a chance of getting contaminated fuel from one or all of the following ways.

1. Sediment/moisture/algae/bacteria flowing from truck to underground storage pump.
2. Sediment/moisture/algae/bacteria flowing from underground storage pump to filling pump 3. Sediment/moisture/algae/bacteria flowing from filling pump to your vehicles tank. Yes all the filters are supposed to catch this, but nothing is 100% and I would almost bet that one of the cost cutting moves of gas stations is to decrease the frequency of filter changes for the pumps. Despite regulations and filter changes it is still possible. I would not risk it if at all possible, but that is just my opinion. (IMHO, I believe is the term used frequently on this forum) Bad gas is less common but still not worth the cost of a engine, or at the very least draining a fuel tank and replacing.

Steve

 

^ you got it ^

In older underground fuel tanks they rot adding rust to the picture. Ma and Pa facilities don't have the cash to replace tanks so they do what they can to stay a float.

Bad gas is usually for leaky underground tanks from ground water and not moving fresh quantities. Stale fuel is fuel not used within 3 months can start to gum and oxidize or varnish.

Try to buy fuel from newer establishment with vehicles that fill frequent. Semi-larger facilities with traffic is a sure sign of fresh fuel. Now as far as getting fuel while a delivery is being completed; This is a problem because ANYTHING on the bottom of the tank is agitated and if you pump fuel during this time it's going right into your tank. Sure the larger particles are going are get caught in the hose filter but not all. You'll be lucky if it's just a 20 micron filter meaning anything under that size can still come through into your low volume pump. The lower volume means that it will not only get stuck in your smaller filters but create a dust cloud on the filter surface. If you open the throttle lets say full, the particles let go and are forced into you engine clogging as it moves. Sure the larger particles will be still in the filter of your pump but the smaller ones that don't get caught make it right in. Remember that the vehicle is only like 10 micron so anything under can still make it 's way through.

Also, during full drops the varnish, sludge, algae and any other deposit is getting mixed up as well. Also I've never seen a trucker vacuum and clean the filler neck before dropping his delivery have you? Dirts going right in!

Now hi volume establishments and newer establishments are a good place to start as they need to commit to the new Polyurathane tanks instead of the old metal ones that are being pulled because of corrosion. Still even with a good tank you still need to worry about the deposits in low volume establishments.

I prefer Chevron Premium fuel with Techron in my rig in a new facility as talked about here especially for towing. Just seems to work and burn great.

 

There is no governmental regulation on fuel gage reading except to read full when full and empty when reading empty. My D when says near empty I have a good 5-6 gallons left (I would prefer it that way then running out,also prevents going all the way empty and sucking up any dirt if in the tank) Now I have an old Ford explorer out back (1991) when that hits empty i mean right when it hits empty your out and walking.

 

No such law that I'm aware of!

As being a law/regulation official and advance knowlage in the way there writtin according to the law it DOES do it's intended job. It might not be the way everyone likes it but it does it's job. If it hit the top or bottom then everytime you hit a big pot hole then it would smack the top or bottom of the tank and cause the shock wave to slam into the electronic sending unit disrupting it's signal and posibly causing an arch. The float arm is cushioned to control that.

Here is some basic info:
http://auto.howstuffworks.com/fuel-gauge1.htm

 

Like I said, I am sure that pump filters are one of the last things to get replaced, and of course they are probably not going to advertise that fact. I work a lot with JET A of course there is a lot more inspection and oversight of aviation fuel including inspections, filter changes and inspection/replacement dates clearly marked.

Speaking of the full when full and empty when empty, there was a fairly recent article (I found it on yahoo news but google, I am sure it is still available somewhere online) about not the fuel gauges of cars, but the oversight of the stations. Simply put there are not enough inspectors to go around, to do station visits and ensure 100 compliance with weights and measures so it is possible in addition to getting bad fuel, but not enough and possibly the meter flowing faster than the pump. Essentially indicating and paying for 5 gallons but in really only getting 4.5, not exact numbers but you get the idea.

Another possible old wives tales is DO NOT FILL DURING THE HEAT of the day, essentially the fuel expands with heat and you may possibly be paying for vapor.

Sounds like we might have another episode of "MYTHBUSTERS"

 

I beleive fuel stays ruffly the same temperature at least the temperature in general. The fumes on the other hand expand but don't quote me on that. I want to get an actual temp on the fuel in different areas temps to test it but to this day I haven't got -r-dun!

I have heared the wize tails but unsure of the out come?

As for inspection personel....... There isn't enough people to go around at least with weights and measures. I knew an old station that after the inspectors would leave they'd slow the counter to make you think you got your fuel but in reallity you got 3 gallons instead of 4 but paid for 4. Then about the same time of year they would change it back. They would come around like clock work. One thing is to look at the seal of weight and measures located directly on each pump to see when it was completed.