[Nrfd79]

Its not the best practice. I've owned a shop for many years and install fuel pump after fuel pump in vehicles with people that follow that rule. The pump sits upright in the hanger assembly so when the tank is low on fuel the pump gets warm and it overheats and then fails. I can't tell you how many fuel pumps we have installed that came right from the gas station. The fuel in the tanks acts a a cooler for the pump. Just my 2 cents. But I have no scientific data to back that up..

[VQ35DE]

Fill up way before the light comes on.

[parish8]

My understanding is some of the fuel the pump is pumping is overflowed into the pump basket. This keeps the fuel pump submerged no matter the fuel level other than running it completely out of gas.

[soloknight6]

I usually wait for the light to come on. No problems.

[Alanarchy]

I usually fill up when I`m at the midway point, but for me it`s out of habit.

[GearheadSS]

I don't wait for the light just in case I need to get somewhere in a hurry and don't have time to stop for gas. I try to fill up at 1/4 or 1/8 at the very least.

[misterjaayy]

The light comes on for me when there is around two gallons left. Its not cutting it that close and I wouldn't think that would be too much of a stress on the fuel system. But what do i know.

I usually wait until 1/8 or less. Psychologically I feel like I'm getting my money's worth out of the tank. Thats obviously stupid but thats just how my mind works.

[PNYKLR2]

Ok, complicated math but I think this map help you both and I'll skip the math part


Scenario

1. Never let it go empty because I like it that way. Help my fuel pump last longer maybe. Security of knowing you can always drive because your ready to go.

2. I always let it go empty because I enjoy not spending time constantly running to the gas station. It's annoying and I only have to fill up once a week or every two weeks.

Oooorrrrrrrr

3. I never fill up a full tank. At 19 gallons you have 170lbs of fuel in that tank. The fuel savings I get from reduced wieght and less wear and tear on suspension components. Less mass means my 0-60 is .0257396 seconds faster. ( Crude example but keeping your vehicle at a half tank vs. full may save you a ton of money over the life of the vehicle.)

To me that should be a thoery that needs more investigation

[dpevans]

The fuel pump pick up sits in the bottom of a bowl that holds about 1/2 gallon depending on what kind it is. Some more, some less. I drove my Caddy for 275k miles and I would wait till as long as possible to fill up just so I didn't have to fill up all the time. When I did replace it because the float quit working the pump assembly is attached to the top of the pump and does not even sit in fuel once the tank is 3/4 full. The whole argument is really nonsense because the pump is a closed system fuel does not lubricate the pump. You are doing no harm in running down till the light.

[hotlap]

I always run it empty (light on) and then fill completely. My last three car were bought new and kept to ~150k miles without any fuel system failures.

My reasoning is that water can build up in a tank if not cycled completely full to completely empty.

[Nino8309]

Originally Posted by Ebbsnflows

For those skeptics that refuse to acknowledge the validity of this problem (probably the same people that say "Smoking doesn't cause cancer. Why would cigarette manufacturers sell something that caused cancer?"

Here is what Walbro has to say - But what do they know, right?

https://walbrofuelpumps.com/why-fuel-pumps-fail

"Frequently running your vehicle on a low gas tank is extremely bad for your fuel pump and fuel system components. On many vehicles, approximately 10-15 times the amount of fuel your fuel pump sends towards your engine gets sent back to your fuel tank. This helps cool down your fuel components and the fuel in your gas tank. By running on a low gas tank, the fuel in the gas tank heats up a lot quicker causing the fuel pump to overheat or even worse, run dry. Avoid leaving your gas tank low whenever possible."

The Camaro has a returnless fuel system so i dont think this is the case here

[Nino8309]

Originally Posted by parish8

My understanding is some of the fuel the pump is pumping is overflowed into the pump basket. This keeps the fuel pump submerged no matter the fuel level other than running it completely out of gas.

Correct.

[guitarman8373]

Every time I fill up, it's usually about 16-17 gallons going in. And it's a 20 gallon tank? So still leaving a good couple gallons left in the tank.

[Chazzz]

Why carry around nearly 200 pounds of extra weight.... I only fill my tank if I'm taking a road trip or if I find gas at a bargain. I know I'm getting better MPG's and I highly doubt I'm doing any harm !