Only so much gas goes in tank

I have an 05 Tacoma 4 door. I just bought it. The guy I bought it from sold it for his son that just went to boot camp so I can’t get any answers when I have an issue. I thought I had a gas mileage problem at first, but I let the truck go to empty and then I refilled the tank to full. Only 10.5 gallons went in. Any thoughts as to why this is a thing? I looked under the truck, and the tank definitely looks like it carries way more than 11 gallons. Is it the float?
Also when I filled the tank it went to Full on the gauge.

 

05 tacoma has a 21 gallon tank. Really couldn't be the float as it would either defy the laws of buoyancy or gravity to go from full to empty.

Honest question, how did you determine it was empty? Maybe a bad gauge? Or there is an 11 gallon something in the tank.

 

Drug mule truck?

 

Very interesting. Sounds like it's showing empty on the gauge when the tank is actually about half full. Did you take it all the way down to the gas light coming on?

 

That’s what I was thinking. The light did come on.

 

This would be interesting

 

Can you slide a dip stick down the filler neck? Get an idea how much is left in the tank.

 

my gauge does the same thing, well sort of. Gas light comes on fill it up and only takes 50 liters. ive just lived with it.

 

The rheostat on the float is bad, it's only reading the top half of the tank.
To test get a gas can and put it in box then run truck out of gas, add gas can and go fill it up.
Stop at ten gals check gauge see if it's still on E then continue filling and watch gauge move.

 

I do not recommend intentionally running your truck out of gas for any reason

 

So much cocaine.

 

By doing some basic math, we can determine that 10 gallons of coke weighs 23 kilos. With a wholesale value of $25K per kilo, that’s $575,000. Wouldn’t it be nice to buy a truck for $10K and find $575K worth of coke in a hidden compartment?

 

I mean maybe. Need to find a way to sell.

 

I was trying to avoid that accusation when I said "11 gallon something in the tank" but it was implied as a possibility

Siphon screen would block that.

 

My fuel gauge sending unit went bad in my old 4runner and it will show full on a full tank but by half tank it would show empty. I just had to learn to fill up by mileage.

 

For what imaginary reason would that be?

 

Its bad for pretty much every part of your fuel system. There is always a bunch of sediment in the bottom of the tank. When you run the tank empty it is possible to pick that sediment up and push it all the way through the system. Theoretically, there should be some fuel in the tank even when you run it out to make that not happen but it's better to not chance it.

 

I'm not sure its true that "there is always a bunch of sediment in the bottom of the tank". The tank is always swishing around and mixing during driving. There is a fuel filter. People run their vehicles out of fuel all the time. If I were you OP I'd put a jerry can in the back and see how far she goes.

 

Pam stop eating all the god damn cocaine