Just how bad is it to always run the fuel tank down to near empty on these cars?

[JimVonBaden]

Originally Posted by Tommm

I have a relative in Michigan who was an engineer at the big three in the warranty department. He suggested I fill the tank when it hits half full because of the cooling issue mentioned above. Based on warranty work he has seen it is not a wives tale. .

I usually do it around a quarter because I drive too many miles each day, and I don't want to fill it up every other day. Twice a week is enough.

No offense to your relative, but even engineers are subject to old wives tales.

[Esteban]

Originally Posted by JimVonBaden

No offense to your relative, but even engineers are subject to old wives tales.

Who are these old wives and why do they tell these tales?

[blue135]

The other question: can old engineers be subject to young wives tails?

[Esteban]

Originally Posted by blue135

The other question: can old engineers be subject to young wives tails?

Touché

[Tommm]

Originally Posted by Tommm

I have a relative in Michigan who was an engineer at the big three in the warranty department. He suggested I fill the tank when it hits half full because of the cooling issue mentioned above. Based on warranty work he has seen it is not a wives tale. .

I usually do it around a quarter because I drive too many miles each day, and I don't want to fill it up every other day. Twice a week is enough.

Originally Posted by JimVonBaden

No offense to your relative, but even engineers are subject to old wives tales.

Numbers don't lie. He gathered the data when he worked in the warranty dept.

But since this is the interwebz, and you have your butt dyno, you must be right.

[JimVonBaden]

Originally Posted by Tommm

Numbers don't lie. He gathered the data when he worked in the warranty dept.

But since this is the interwebz, and you have your butt dyno, you must be right.

Care to post up these numbers? If not, your uncle is no more than a 5 year old with crayons! See how this works?

[zx10guy]

Here's a really good in depth explanation on fuel pump failures:

http://www.agcoauto.com/content/news/p2_articleid/195

It further reinforces the premise that fuel pumps are cooled and lubricated by the fuel passing through it versus being submerged in fuel. It also goes over water and contaminants causing failures too.

[Tommm]

Originally Posted by JimVonBaden

Care to post up these numbers? If not, your uncle is no more than a 5 year old with crayons! See how this works?

It not my uncle, its my cousin. And no, I don't care to post up numbers because I didn't write them down. In fact, he didn't read me the exact numbers, he told me the results of the study. It was proprietary warranty information. See how life works for grownups?

I guess he is no more than a kid with crayons, which is more than he would say about you.

[zx10guy]

Originally Posted by Tommm

I have a relative in Michigan who was an engineer at the big three in the warranty department. He suggested I fill the tank when it hits half full because of the cooling issue mentioned above. Based on warranty work he has seen it is not a wives tale. .

I usually do it around a quarter because I drive too many miles each day, and I don't want to fill it up every other day. Twice a week is enough.

Originally Posted by Tommm

Numbers don't lie. He gathered the data when he worked in the warranty dept.

But since this is the interwebz, and you have your butt dyno, you must be right.

Originally Posted by Tommm

It not my uncle, its my cousin. And no, I don't care to post up numbers because I didn't write them down. In fact, he didn't read me the exact numbers, he told me the results of the study. It was proprietary warranty information. See how business works?

I guess he is no more than a kid with crayons, which is more than he would say about you.

I wonder if the place your cousin worked at bothered to spend the time to tear down the faulty fuel pumps to determine what the actual failure was. I would bank on no as it's time consuming. Unless there's a huge rash of failures I just don't see any manufacturer spending that much time and money doing a post mortem on these parts. Even if the manufacturer did, there's really no way to tell if the fuel pump died due to being run dry or if they were subjected to your hypothesis which is the physical pump wasn't submerged enough in fuel to cooling through the casing.

I just don't see how any modern fuel pump would be designed to get operational cooling through being submerged in fuel. If a car manufacturer actually designed a fuel system to operate this way, there would be a rash of complaints as there would be a lot more failures as people would never willingly get a car which would require one to constantly fuel up when the fuel gauge hit half way. I know I wouldn't tolerate it.

I know it's anecdotal, but with all the cars I've had, I've never had one that had a fuel pump failure. They were all domestics going back to the questionable period with the 135i being the first car I've owned being non-domestic. I've actually run one car out of fuel twice with no fuel pump failure. I did replace the fuel pump in that car because I had a 50 HP shot of nitrous hooked up to it. Wanted to make sure there wasn't any weak links in the fueling as it's critical with nitrous.

Did you read the article I linked to?

[KNS]

Zx10guy,

Great article. Though the part about not fueling up while the tanker is refueling is a bit of myth. Tanker trucks may visit a station every day, sometimes more than once. There’s no way to know if the truck left just before you got there, which may have been minutes before. If there is crap in the bottom of the storage tank it’ll be stirred up for a long time before settling. Millions of people are refueling while the tanker is bulk loading the storage tank but we don’t see a rash of fuel pump failures across the country.

Also, the station should (hopefully) be changing their filters regularly to keep the worst of the dirt out of your tank. Unfortunately dirt still does end up in our tank and there’s not a lot we can do about it.

[JimVonBaden]

Originally Posted by Tommm

It not my uncle, its my cousin. And no, I don't care to post up numbers because I didn't write them down. In fact, he didn't read me the exact numbers, he told me the results of the study. It was proprietary warranty information. See how life works for grownups?

I guess he is no more than a kid with crayons, which is more than he would say about you.

So, both of you talk trash with no clue or facts. Got it.

[Tommm]

Originally Posted by zx10guy

I wonder if the place your cousin worked at bothered to spend the time to tear down the faulty fuel pumps to determine what the actual failure was. I would bank on no as it's time consuming. Unless there's a huge rash of failures I just don't see any manufacturer spending that much time and money doing a post mortem on these parts. Even if the manufacturer did, there's really no way to tell if the fuel pump died due to being run dry or if they were subjected to your hypothesis which is the physical pump wasn't submerged enough in fuel to cooling through the casing.

I just don't see how any modern fuel pump would be designed to get operational cooling through being submerged in fuel. If a car manufacturer actually designed a fuel system to operate this way, there would be a rash of complaints as there would be a lot more failures as people would never willingly get a car which would require one to constantly fuel up when the fuel gauge hit half way. I know I wouldn't tolerate it.

I know it's anecdotal, but with all the cars I've had, I've never had one that had a fuel pump failure. They were all domestics going back to the questionable period with the 135i being the first car I've owned being non-domestic. I've actually run one car out of fuel twice with no fuel pump failure. I did replace the fuel pump in that car because I had a 50 HP shot of nitrous hooked up to it. Wanted to make sure there wasn't any weak links in the fueling as it's critical with nitrous.

Did you read the article I linked to?

That's a few questions you will probably take to your grave. I've owned over 50 cars and none have had a fuel pump fail. So?

Originally Posted by JimVonBaden

So, both of you talk trash with no clue or facts. Got it.

Then trash talk it must be.

[zx10guy]

Originally Posted by Tommm

That's a few questions you will probably take to your grave. I've owned over 50 cars and none have had a fuel pump fail. So?

The so part is I've never religiously refilled the tanks of those cars at halfway to keep the fuel pumps from failing. And none of them failed to include the car which used a stock fuel pump which wasn't designed for the extra demands of nitrous injections. Yet the fuel pump didn't take a dump even though I would run the tank near empty.

So the point being is unless your cousin or the company he worked for took apart the fuel pumps that have failed and tracked the fueling/operational habits of the owners, the premise he's pushing is a wive's tale.

[zx10guy]

Originally Posted by KNS

Zx10guy,

Great article. Though the part about not fueling up while the tanker is refueling is a bit of myth. Tanker trucks may visit a station every day, sometimes more than once. There’s no way to know if the truck left just before you got there, which may have been minutes before. If there is crap in the bottom of the storage tank it’ll be stirred up for a long time before settling. Millions of people are refueling while the tanker is bulk loading the storage tank but we don’t see a rash of fuel pump failures across the country.

Also, the station should (hopefully) be changing their filters regularly to keep the worst of the dirt out of your tank. Unfortunately dirt still does end up in our tank and there’s not a lot we can do about it.

I still would rather not fuel up when the tanker is there to top off the underground tanks. I took some environmental hazmat training and ran across discussions of many gas stations with high levels of soil contamination from leaking underground fuel tanks. I have to imagine filling the tank would exacerbate any crud that has seeped into the tank through any cracks in the tank.

You're right that I wouldn't know if a tanker had just left the gas station. But what's certain is the high probability of stuff being stirred up while the tanker is there filling the tanks. I could be making what amounts to something that is no big deal into an imaginary issue. With that said, I have never left a gas station when a tanker is there filling the tanks though.

[JimVonBaden]

The ONLY fuel pumps I ever had fail were manual ones on SBCs. Of the 50+ cars, and 40+ motorcycles I have owned, never one fuel pump failed, and I regularly run them past 1/4 tank to empty. But I am not ignorant enough to assume my experience is the be all. I am smart enough to know the truth based on facts, facts listed here already!