Driving your 3rd Gen Tacoma When the Low Fuel Light is On -

The first that comes to mind was a Jeep...

 

Yes and no. I think we all realize its easier to sip a drink through a straw when the drink is full vs just about empty.

 

By the time its sucking air you're on the side of the road.

 

You're missing my point entirely. More "sucking" force is required in a low tank than a full tank. Its physics.

 

Possibly but I think the effects on the fuel pump with less than 3 gallons in the tank are negligible.

 

The high pressure fuel pump on the engine isn't sucking fuel from the fuel tank. It is being delivered fuel from the fuel pump, then further pressurizing the fuel.

 

I'm talking about the fuel pump in the top of the fuel tank. Not the engine pump.

 

The HPFP is the one on the Engine.

 

This is a known and proven problem on a number of motorcycles. I believe Kawasaki has this issue but I have to confirm with a friend. He had one of the models with the issue and has been through 2 pumps now.

So it is confirmed on some vehicles as fact. Not Tacoma’s but it is an issue for some more than others.

 

So did I miss something or am I being told that waiting until my gas light comes on and filling up 5-10 miles after is damaging my fuel pump?

 

I know I can go 400 miles without filling up! My dealer filled it for me, I still had gas in it 2 weeks later when the light lit. I could go another 65 miles!
I have the 4 CYD

 

What’s the fricken point. Just fill the damn thing up already !!!

There are to many variables with fuel mileage ..... tires , pressure , driving habits , stop and go driving , road and weather conditions .... etc

 

on the highway, at 65-72, mostly flat, i can consistently get around 465 miles before the light comes on.....i fill up and put anywhere between 19.5 and 20.2 gallons in....if i push it on trips, i am sure i may be able to get 500 miles.

 

Before getting my Tacoma, my regular driver was my trusty 93’ Toyota Camry. I always drove around until near empty and never filled up past a quarter or half a tank each time at the most. Perhaps it’s the Toyota reliability, I never had any problems with the fuel pump. It still has the original OEM pump.

 

Yeah, I mean honestly I can't believe how many people want to risk potentially damaging their fuel pump. I just fill her up with gas when it gets low unless I can't for some reason. Why risk it?

 

Way to not read the thread. Your '93 camry didn't have the HPFP that the new Tacomas have. It's not the same.

 

My Duc with the same Bosch pump found in most Ford FI cars / truck lasted well over 100k. It has a 5.5gal tank that I routinely fill with 5gal. I swapped it at a total cost of $30 using the "Ford" parts more as a preventative measure.

Just sayin'.

 

It’s not as much as debris, but more of the pump working more. Less pressure/liquid, the more the pump has to suck in = accelerated wear.

I have had to help a lot of my buddies replace fuel pumps cause they kept doing that, but it normally fails around 150k. None of my vehicles (owned 8 prior to my tacoma) had fuel pump failure and I took them over 200k. Also, I have gone thru days at a time where there was no fuel available (like what happened in parts of Texas) so it’s nice to have atleast 1/4 in the tank.

I also think it’s habit cause Air Force vehicles per reg have to stay above half a tank or get written up if you go below 1/4 (it’s to keep the fuel pump from working too hard since they keep these trucks 10+ years).

 

It's all about head. No not THAT head, hydraulic head! So you wanna get into the weeds on why not to run your fuel tank low eh? You really want an explanation?

Here:
In fluid dynamics, head is a concept that relates the energy in an incompressible fluid to the height of an equivalent static column of that fluid. From Bernoulli's Principle, the total energy at a given point in a fluid is the energy associated with the movement of the fluid, plus energy from static pressure in the fluid, plus energy from the height of the fluid relative to an arbitrary datum. Head is expressed in units of height such as meters or feet.

The static head of a pump is the maximum height (pressure) it can deliver. The capability of the pump at a certain RPM can be read from its Q-H curve (flow vs. height).

A common misconception is that the head equals the fluid's energy per unit weight, while, in fact, the term with pressure does not represent any type of energy (in the Bernoulli equation for an incompressible fluid this term represents work of pressure forces). Head is useful in specifying centrifugal pumps because their pumping characteristics tend to be independent of the fluid's density.

For our fuel pumps, there is "elevation head" to consider. Every pump has to have a suction port, even hydrostatic pumps. They use a "charge" pump to replenish the circuit and they have suction ports. Got it? Moving on...

Whatever the size of your pump's suction port (let's say 1/2" for argument's sake) there is a corresponding "column" of fluid (in this case, gasoline) that is the same diameter and runs from the suction port of the fuel pump to the top of the tank level. This "weight" of this column of gasoline is what "forces" the gasoline into the pump. The higher the column of gasoline, the easier your pump works. It doesn't have to "suck" as hard to draw the gasoline in and pump it out the other side.

In other words, the fuller you have your gas tank, the easier your fuel pump has to work as it has "head" pressure forcing the fluid into the suction port. Run it low, there is not as much head, the harder your pump has to draw in fluid to push it to the engine compartment.

Now, your tank also has "baffles" and that is to prevent sloshing of gasoline around when cornering, possibly uncovering the suction port of the fuel pump. This is key: Even if your fuel pump is designed to operate under low head pressure (running your gas tank low), It will be much better for the pump and add longevity to the fuel circuit if it has a higher head pressure (Keeping plenty of gas in your tank).


So there you have it... a technical explanation of why it is better for your fuel pump to have plenty of fuel in the tank.
Greg

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Update, Light came on and drove 18 miles home. 2 miles round trip from the gym and 2 miles to the gas station. Filled up the tank and it was 19.2 gallons. So maybe, another 30-40 miles depending on how you drive.