[Cough]

I decided to do an assessment on my fuel tank capacity. I ran the vehicle to empty. Yes completely empty. I carried a container with me so I had around two gallons in the container for when I finally ran out

The low fuel warning light came on. At this point the manual indicates I have 2.5 gallons or less remaining in the tank.

The DTE = zero came on after that of course.

From Low Fuel Warning to empty I drove 83 miles. My car gets around 25 mpg at this type of driving so that indicates around 3.3 gallons was left at that point - more than the manual expects.

From DTE=0 to empty I drove 67 miles so that indicates about 2.7 gallons was remaining at that point

At shutdown I added 2 gallons. The DTE came up to 3 miles which is not consistent with the numbers on the way down but not a huge difference (less than a gallon)

I drove a very short distance - maybe a mile - to a gas station and filled up. I clicked offs several times and could finally see a little fuel in the filler neck so I stopped. I pumped 16.1 gallons.

So allowing for a little consumption on the way to the gas station, the tank held 18 gallons (2 from the container and 16 from the gas station). This in fact is more than the manual says (17.2 gallons) but of course some will be concerned I flooded the vapor system.

My conclusion: There is not a capacity issue with the gas tank. Maybe some issues with the filler neck (clicking off easily). Certainly a conservative warning light since there are still at least two useable gallons in the tank after warnings.

On side information, some of course will say don't run to empty since there is a risk of sediment and filters plugging etc. With a new car I didnt figure that was a problem. I was able to drive the car a few hundred yards on battery power (to get to a safe refill parking) even after the gasoline engine shut down. The "engine has shut down, refuel immediately" alarm did not clear immediately. After I put in a couple of gallons and restarted the vehicle the alarm came on again. It referenced "see owner's manual" but a quick check of the owner's manual didn't tell me anything. I turned off the vehicle and started it again and all the alarms cleared.

Again pardon the pun, but ymmv

 

[Cough]

My test on fuel tank capacity was a couple of months ago. Nothing has improved since then. When I took the car into the dealership it was kindof "too bad, so sad but we are not going to do antything and anyway you should not click off the pump more then once bceause you may flood the charcoal canister and get a CEL"

 

[Cough]

My conclusion was that the tank is probably the right size. The issue is there is too much unusable at the bottom and there is too little fillable at the top.

While some early complainers got some attention that didnt fix anything, anything recent just gets rejected as an issue by the dealership and by Toyota.

YMMV

 

[Cough]

Technically correct in that if you are prepared to run out every time: I can run at least 3 gallons below DTE=0. But if this 3 gallons is left alone (because of screaming kids saying we are all gonna die on the freeway) and you dont fill past one pump click (because my service manager says he will charge big $$$ to clear the CEL) you are probably limited to a usable volume of 13 gallons.

 

[Cough]

In response to your edited post, it would seem Toyota could recalibrate the gauge sensor to add 30-60 miles to the end of DTE. Until then, I know I won’t feel my normal urgency to find a gas station when I see <50 DTE.

That said, after filling, DTE typically reads ~530 miles which is inline with a 16-17 gallon tank, but goes down somewhat faster than the miles traveled.

Mine has been in for investigation, and the service dept wont/cant do anything re calibration. I have just completed a long (2000 mile) trip and like you, I am no longer in a hurry to fill up until I hit DTE=0. BUt the issue after that is that, unless you make copious notes, it is easy to forget at which Odometer reading DTE was zero and therfore how much longer I can drive before refill. The sphincter gets a lot tighter after just a few minutes of ""Zero miles left ... FILL UP NOW"" And of course on a long trip I dont want to pull off any earlier than I have to.

So yes I modified my note while you were immediately responding, but I stll hold on to the concept that the full tank capacity is unusable.