I have read in a couple of threads that it is recommended not to drive the vehicle at low fuel levels. Now I have couple of questions based on that:
1) How does one define low fuel level? (is it when the low fuel indicator light comes on)
2) What are the negative effects of driving at low fuel levels?

Thank you in advance.

 

i always ride on light and my car still runs fine

 

Riding around all the time on less than 1/4 tank is bad for your fuel pump, and for condensation.

The fuel pump sits in your gas, and uses it to cool itself, so less fuel = less cooling, and more wear and tear on your pump.

An empty tank is more prone to water condensation, than a full one, so if you just want to put a little bit of gas in your tank at a time; suck it up once, fill it up, and then top of every now and then from there.

 

Mr. Hyde,

Would the condensation in the fuel tank affect the performance (mileage, engine maintenance, ....) of the car?

 

Condensation is made of water
Water is not combustible
Fuel IS!

 

I'm not Mr. Hyde, but to answer your question: Yes.

It's in essence the same thing as putting water in your tank. Allbeit, it's not a ton of water, but still; would you put in 1/4 cup of water into your tank everytime you filled up? How bout an 1/8 of a cup?

Water in the tank is just a bad idea. And as Mr. Hyde explained, running your car on low fuel increases the chances of condensation: i.e. water in your tank.

Just fill up every 200-220 miles and you should be fine. You'd just have to visit the gas station more often, but would spend the same amount of money.

 

Fill up every 200 miles yikes
Maybe if there were a storm watch and needed full tank all the time!

Drive it to a point just before fuel light and fill up

 

I also have a dollar per amount of fuel remaining thing in mind- so I know it needs 40 bucks- stop at the station

 

dam how much do you pay per gallon? $40 is a lot for a fill up

 

Usually costs me close to 40 or so every time i fill up (which is almost daily) cause i run it damn near empty every time

 

A friend of mine told me when I got my first car to always wait till it was almost empty to fill up, something about getting tiny specs of dirt from the gas pump in your tank...I always thought that just seemed stupid, but have always followed her advice. I guess it's time to change my ways. A failed fuel pump doesn't sound like any sorta fun.

 

i don't think it makes a big difference, especially if you run good fuel system cleaner every 5k like I do.

 

Todays gas price is 3.05 per gal for 91 octane
So $45 is what I normally spend- thats 15 gallons
because I fill up at fuel light or before

 

eeks thats a lot. where do you live. nyc is going up there pretty soon tooo

 

Honestly where do you think the fuel pick up for the pump is?? Its in the bottom of the tank. It doesnt matter if its half full, full or empty, its still drawing in the fuel from the same spot. Plus there is a sock filter on the inlet to trap stuff before it goes into the pump.

 

270,000 miles and I push it into the gas station. No idea what you are talking about.

 

I just go until the gas light comes on. She usually takes about 13.5-14 gallons to fill up.

 

The normal problem with condensation in a fuel tank is rust resulting from storing a vehicle. The tank walls are uncovered and condensation can form and sit there. That isn't a problem unless the vehicle sits for an extended period. Filling it every week or so and sloshing around while driving keeps the walls relatively protected. If you're not going to drive it for a while, even a few weeks, fill the tank. Otherwise, just drive it until you need fuel.

As for the pump, yes many pumps are submerged, but the primary reason is because fuel injection systems operate at high pressure, which requires the pump to "push". Putting them in the tank eliminates the suction side of the pump.

Just drive it 'til the light comes on.

 

Kind of off topic, but how many miles do you guys normally have before you need to fill up on a full tank? I think I get ~ 220 or so, and that's running on a near to empty tank. But I usually ride locally. Is this pretty low?

 

Never said i believed it. just an old habit. most likely will be fueling up just before 1/4 tank now though instead of taking it all the way to near empty.

 

Just fill up when you see cheap gas for whatever brand you want. Saves ya money, and you're usually not empty when you find the cheap gas driving around randomly. Just gotta get in the habit of not being lazy about filling up when you're not empty.

 

yeah thats about normal for a TL-S. i average 17mpg all town miles. and it's bad town driving with about 25 damn stop lights to and from work.

 

You have 270k on your TL? I think that's the most on this site.

 

Your first mistake.

 

someone said something abut using shell v-power in another thread, it's cleaner and burns better from what i understand. i wonder if after using it for a fewtanks if your fuel mileage might get slightly better with it as well due to that...

 

Hahaha LOL!

 

 

if its a very small amount of water wouldn't it just get vaporized by heat from the engine?

 

HEY I don't go around here calling ppl names! (unless they actually are stupid or total jerks) I've found your threads to be very informative, but JEEZ, sorry if I followed one of my friends advice when it came to my first car...i actually learned from reading this thread that she was wrong and even said that i didn't quite believe her, that doesn't make anyone stupid. Also, i already knew where my fuel pump is loc. but you had to get all rude about that too on the first page.

Sorry I'll get over it. Just annoyed cos' I was only trying to put in my legit on a topic that interests me.

 

^dude relax, he agrees with you. The sign is a joke. It just states "Im With Stupid" as in ditto I agree lol

 

What would be a good fuel system cleaner to use? I sometimes use STP Fuel System Cleaner, is that any good?

 

STP complete is good. It comes in the silver bottle.

 

Eh, your probally right. I was having a shitty day yesterday anyhow....work issues.