Fuel Level Question???

[ScottyBoy]

I've never heard of any issues from driving on a half tank. But I HAVE heard many mechaics say that you should never make a habit of running on 1/4 tank or less ALL the time. It will cause a fuel pump to fail much faster. They say that it makes the fuel pump work harder since there is less gas being gravity fed into the pump. They say it also makes the pump run hotter because it doesn't stay fully submerged to cool itself off. Kinda makes sense if you think about it.
I think that would mainly apply to people who always put like 5 bucks at the time in there and drive it till it just about kills, then put like 5 more bucks in.

I always use this as law. Though the pump does sit in a cavity that contains fuel, which keeps it cool. If you hit potholes it can cause the cause fuel in that cavity to spill out. I tend to never let the tank get below 1/4. You know when your on that last 1/8 the gas station is never close by.

I think there is a tiny bit of logic in the "super low levels might not cool the pump as well" theory... but you guys are out on a limb with the gravity feeding the pump bit. Mechanics are like a bunch of gossiping old ladies... They tend to believe in voodoo and drink a lot.

It seems logical to me that a full tank would be better than an almost empty tank if you don't drive it very often. Less air and more fuel seems like it would keep the fuel from oxidizing or deteriorating in the tank. That could be just wishful thinking though.

It does make some sense to me. It seems logical that the pump wouldn't have to work "quite" as hard if it had more fuel in the tank. Think about it like this: when you first take out that oil drain plug, that oil damn near gushes out. As the oil level in the pan drops, the oils drains slower and slower. So it kinda makes sense that if you had 20+ gallons on top of that fuel pump, it wouldn't have to work quite as hard as if it only had like 4 or 5 gallons on it. I'm not saying your pump has to strain its ass off to pump when the fuel level is lower, but I'd think it would be a little bit less (and I use the term "little" pretty loosely) of a strain on the pump if it had more fuel in the tank.

 

[RebelThunder]

I usually fill up when I'm between 1/4 and 1/2.

 

[mr_bots]

A GMT-800 isn't really a good example for how letting gas get low can lessen it's life. That generation wasn't known for having reliable, long lasting fuel pumps to begin with.

 

[Mcdiver]

I agree with the full tank to keep the pump cool thing, I fill up when I get to 1/4 tank in my work truck. Mostly because if I don't I will be stopping again before the end of the day. I average between 500 and 1000 miles a day so fill up every time.

On my personal truck, 98 C-1500, I fill it all the way up at 1/4 tank. Have not had a problem with fuel pump since. But that only happens every 2-3 months or so.

 

[Zembonez]

I've never heard of any issues from driving on a half tank. But I HAVE heard many mechaics say that you should never make a habit of running on 1/4 tank or less ALL the time. It will cause a fuel pump to fail much faster. They say that it makes the fuel pump work harder since there is less gas being gravity fed into the pump. They say it also makes the pump run hotter because it doesn't stay fully submerged to cool itself off. Kinda makes sense if you think about it.
I think that would mainly apply to people who always put like 5 bucks at the time in there and drive it till it just about kills, then put like 5 more bucks in.

I always use this as law. Though the pump does sit in a cavity that contains fuel, which keeps it cool. If you hit potholes it can cause the cause fuel in that cavity to spill out. I tend to never let the tank get below 1/4. You know when your on that last 1/8 the gas station is never close by.

I think there is a tiny bit of logic in the "super low levels might not cool the pump as well" theory... but you guys are out on a limb with the gravity feeding the pump bit. Mechanics are like a bunch of gossiping old ladies... They tend to believe in voodoo and drink a lot.

It seems logical to me that a full tank would be better than an almost empty tank if you don't drive it very often. Less air and more fuel seems like it would keep the fuel from oxidizing or deteriorating in the tank. That could be just wishful thinking though.

It does make some sense to me. It seems logical that the pump wouldn't have to work "quite" as hard if it had more fuel in the tank. Think about it like this: when you first take out that oil drain plug, that oil damn near gushes out. As the oil level in the pan drops, the oils drains slower and slower. So it kinda makes sense that if you had 20+ gallons on top of that fuel pump, it wouldn't have to work quite as hard as if it only had like 4 or 5 gallons on it. I'm not saying your pump has to strain its ass off to pump when the fuel level is lower, but I'd think it would be a little bit less (and I use the term "little" pretty loosely) of a strain on the pump if it had more fuel in the tank.

If the fuel was running out and down on the ground, there might be some validity here. Since the pump us pumping uphill anyway, there is no gain from the weight of the fuel... at least not after the first 1/4 second of pumping. The pressures these pumps work with would require a HUGE amount of help from gravity to help at all.

It may sound good to you, but I'm not buying it.

 

[Bigredmariner]

I fill up when I get to needing about 20 to 22 gallons. That's usually less than a quarter tank but before the idiot light comes on. I am a creature of habit though, I know exactly where I'm gonna fill up every week.

 

[Zembonez]

I fill up when I get to needing about 20 to 22 gallons. That's usually less than a quarter tank but before the idiot light comes on. I am a creature of habit though, I know exactly where I'm gonna fill up every week.

at a GAS station?

 

[nobrakes00]

I fill up when I get to needing about 20 to 22 gallons. That's usually less than a quarter tank but before the idiot light comes on. I am a creature of habit though, I know exactly where I'm gonna fill up every week.

at a GAS station?

 

[Texas Jim]

I fill up when I get to needing about 20 to 22 gallons. That's usually less than a quarter tank but before the idiot light comes on. I am a creature of habit though, I know exactly where I'm gonna fill up every week.

at a GAS station?

That would probably be a good place...

 

[f150fella08]

i always fill up entirely..when it gets down to 1/4 tank i will fill up