Here's why... my understanding is that the fuel pump is lubricated and cooled by the fuel. There is a reasonable chance that it could be damaged. That would negate the savings from fewer fill ups... also, you need to hope that you run out of gas where it's safe to do so (vs. on a bridge with no breakdown lane)

 

When the computer showed "-----".
I knew one shell gas station which is .5 - .7 miles away. So, I felt a liltle bit better.
Thanks though...
I'm sure that tips is useful for folks here.

 

Here are two more reasons:

1. Any sediment, sand, junk, misc. particles, etc. that is in your fuel tank will settle to the bottom, and so the fuel at the bottom of the tank will necessarily carry with it more "junk" than other fuel. That, in turn, will clog your fuel filter more quickly than normal, which can lead to either (a) reduced fuel flow or (b) the need for more trips in for service to get your fuel filter replaced (or worse, to have your injectors cleaned out). Any savings gained by not having to refuel as frequently could be eaten up by trips to the dealer for service.

2. Gas evaporates (and condensation forms during winter). Driving around with only a few gallons in your tank, or letting your car sit in your garage with only a few gallons, means you have a lot of ambient air in your tank. This means you will lose gas more quickly to evaporation and/or you can have condensation form in your gas tank. I have read that in the winter, when temps are extremely cold, you should never let your car sit with less than a half tank in it overnight, or condensation can form leading to water in your fuel.

 

dam i would never do that

 

while those are based on some theory, id say they are more urban legends than anything else. not with modern cars.

 

Yep.

 

For these situations, people start saying that the car wil start to suck up crap from the bottom of the tank - thats not true, as the car draws fuel from a low point in the tank anyway!

what can be more of an issue is that you can damage your EXPENSIVE fuel pump, mounted in the tank. The pump is immersed in fuel and relies on it for cooling and lubrication. If it begins to get starved, it wont be properly cooled and lubricated and will have its life shortened.

running that low isnt heroic - its just stupid!

steve

 

Last year coming up home from Bimmerfest in my buddy's 02 540i/6, we forgot to fill up before the next long stretch of road and his miles remaining dipped into zero. Of course we were both sweating bullets out of our asses and amazingly after an extra 15-20 miles later we barely managed to crawl into the next station. So yeah, the measurement isn't 100% accurate.

 

I don't see any benefits in running the tank down to Zero although some seem to get a kick out of it. Besides risking damage to the fuel pump, the hope to make it to the next gas station can quickly be ruined by sudden stop and go traffic or other unforseen events. I usually plan ahead and never let it go lower than 30 or 40 miles (my wife gets already nervous when the needle appoaches 1/2). Gives me peace of mind and actually prolongs my life by avoiding unnecessary stress. Traffic is already bad enough in and around NJ.

Felix

 

Agree with ya.
Before I decided to change my gas from chevron to shell.
I called the Service agent from BMW Seattle. And, He said
"Make sure you fill your tank with the new gas when it's nearly empty.
that will give you more positive benefits in the future."