Fuel Tank Capacity Question

So on my window sticker, it says 38 gal fuel tank. I just finished the first tank of gas and drove it until range was only about 60 miles. When I refilled it, it held 28 more gallons. This tells me it’s def not the 26 gal tank but I figured it would’ve taken more considering my range only indicated I had about 4 gallons left. Is there a built in reserve of 4-5 gallons on these??

 

There is a 5-7 gallon reserve in the tank to keep the fuel pump submerged to prevent overheating. When you are on E, the system is accounting for the reserve being there at all times.

 

I drive well past the fuel light and typically put in 32.5 gallons. The light comes on very early.

 

Ok good deal. So basically has a large reserve.

 

Ok makes sense. Good for peace of mind. I’m glad it has such a large tank for both towing and hunting purposes.

 

Driving the range down to 0 miles typically results in a fillup of about 30 gallons. Sometimes a little more, sometimes a little less.

 

So basically what I’m hearing is this is the first vehicle I’ve owned where driving to E is safe to do lol.

 

Yep. This is a common question on the forum. Totally “normal”

 

I do it regularly in town, more hesitant to do so when looking for gas on the interstate.

 

You gotta take into account the overall length and width of the tank plus the fact that the pump is not sitting directly on the bottom. When on an incline it matters even more. 5 gallons spread over a large area the size of the tank only equals a few inches of depth. Add an incline and you could easily be overheating the pump at times. Not exactly wise when gas is readily available. Ever been on a tall or long bridge and an accident ahead shuts down the road for 3 hours??? It does happen, sometimes for longer times. Keep it a good half if you can.

 

I ran out of gas once showing 1/4 tank in an old Jetta. Since then, I make a habit of rarely going below 1/4 tank without filling up. I just wanted to be sure it was a 38 gal tank as it should be when the range seemed different than what I was expecting.

 

I’ll agree with everyone. The reserve in this tank is large. This is the first vehicle I have ever owned in 20+ years that in my daily day-to-day I will let the gas light come on.
The second it does, I fill it.

If we are traveling, I will just top the tank when convenient without letting it go down low.

 

i like (not really) when you pick up your brand new Tundra at the dealership and it shows 600 miles range on the display. then when you fill it up for the first time it drops to 520 miles.

 

the question that I have never seen answered is, are all 38 gallons usable? or will the truck become inoperable at some point with several gallons of fuel still remaining in the tank.

 

It’s about 430 for me.

In one of the gas tank size threads there was someone who ran it down and said his took 36 gallons to fill it. I think the most I’ve ever had go in was 32.

 

I have no clue on that one. I’d guess if you were on level ground and the fuel wasn’t slothing around the pump would have access to nearly all the fuel. But who knows how much fuel is needed to keep the intake submerged. I’ve never seen a picture of the pump.

 

FYI.....The fuel pump doesn't need to be totally submerged. It's cooled by fuel flowing through it.

 

I ran my 2017 for 70 highway miles after the warning light came on and the tank would only take 32.8 gallons.

 

not true.

LOTSOFTOYS is a toyota mechanic:
Ask the Toyota mechanic! | Page 41 | Toyota Tundra Forum (tundras.com)
Ask the Toyota mechanic! | Page 41 | Toyota Tundra Forum (tundras.com)

 

On my '17 I think my 3 year average was about 15.8 (mostly highway miles). In that particular episode I described I was on a NY to Boston round-trip and it was all highway miles. I don't have enough data on my 2021 Pro yet for an mpg comparison.... I've had it 6 months and only put 450 miles on it.... all local mileage.

 

Just disconnect the negative on your battery for a few minutes. It'll say about 600 again.

 

What does that do, please explain? I can only get at most 420 miles on my '20 truck. I remember getting over 500 when I first bought it. But I notice when I pump gas the pump shuts off, and I can see plenty of room to keep adding fuel.

 

420 is about the most you will get. 500 when you bought it is because the truck hasn't learned the drivers driving pattern. When the pump shuts off, do not put more in it. You will flood the evap system.

 

Everything I find about my 2015 Tundra says my fuel tank has a 26.4 gal capacity. I've driven it down to maybe 10 to empty but when I fill up, the most I've ever put on it is 18 gallons. Is is an 18 gallon tank or a 26 gallon tank?

 

I'm with you.

I like never getting below 1/2 tank.

However, I'm doing a test to see what type of fuel works best for me (and "best" is relative to me, not just mpg). So for the first time ever I've been running it to the E for a few tanks.

And I usually get close to 19 gallons in, sometimes closer to 18.

Seems to me there's a lot of protection built into it to prevent something.

My Uncle Master Mechanic told me running low is hard on the fuel pump, which matches what the others said above in this year old thread.

 

Yes, for me it’s like 10 gallons reserve