Fuel tank capacity 18.5 gallons real or symptom of problem?

I closely track the fuel and mpg on my 2021 4WD Tacoma. My fuel tank only holds 18.5 gallons, but the manual says it holds 21.1. The vehicle seems to know this as at fill up it predicts my miles to empty as between 310-350 miles based on my average mpg of 18-19 mpg. Also, as hard as I try I can't get my average mpg above 20 mpg, which is lower than advertised.

Does anyone else have a similar sized tank and similar mpg or is there something wrong with my truck? If so, any idea what is wrong?

Thanks.

 

Standard in the automotive industry as far as capacity and fill up goes; you don't completely drain your tank and tow it to a gas station right?

When you hit the low fuel light, you have a "reserve" left to get you to the nearest gas station.

 

21.1 - 18.5= 2.6 gallons
2.6 x 17.5 mpgs = 45.5 miles in reserve.
Sounds on point

 

Welcome to TW!
Seems that you must be a newbie to vehicle ownership.
The most that I have ever put into my Taco's fuel tank is 19.4 gallons. I'm sure that the tank was not absolutely empty. Would not have wanted it to have been run completely out and quit as that can result in interesting restart problems.
As far as MPGs go, my best (calculated) is 22.1, and the overall average from Day 1 is 18.4.
Your truck is fine. It'll improve slightly over time if you learn how to drive to optimize fuel consumption.

 

Welcome to TW.
Tank isn’t empty as mentioned.
And the mileage estimates are not accurate especially if you idle a lot.
I’ve seen 9 mpg and the estimate on distance of miles till MT were sad.

 

I never let my fuel tank get to empty, it's just not good for the fuel pump in there. Fuel pumps need the fuel for cooling to survive. At any rate if I drive 65 mph or less, I've always got 22 mpg, and change. This is during the summertime. In winter, its between 19-20.

 

I put 19.2 gallons in my tank today. My low fuel light was not on yet.

 

I got 16.8 before I put rtt and lift. Now I get 14.9

 

I’ve lifted my truck, have a Diamondback cover, bed rack, RTT with its top sitting a few inches above cab height and 265/75r16 E load tires and get approximately 18-19.2mpg. I’ve learned to slow down and keep the truck at 65-68mph for best fuel economy.

Prior to the RTT I was averaging 15mpg because I was impatient and wanted to do 70-80mph all the time. Slowing down is the best way to increase fuel economy.

 

Yes- there is definitely something wrong with your truck - and with you, you SFI.
You probably drive a 10 year-old POS Chrysler 200.

 

I have studied this a lot. When I hit the empty, light comes on I still have 6-7 (1 1/2 gals) liters left before filing. This means I can go another 70 km ( 43miles) safely to the nearest gas station.

 

Hope for 17mpg, expect 15mpg

 

you can probably go at least 60 miles after it says "range=0" i have 3 gallons left when it says i'm empty.

 

I'm not even going to talk about my miles per gallon but when I go to fill up when my truck says I have 3 mi left until empty. Which yeah I know anyways, I can put right around 18.9 to 19.2 gallons in before the pump clicks when it tells me low fuel it only estimates. I have 3 gallons worth of fuel left at the miles per gallon I get when I'm towing when I'm not towing doesn't matter when I get to around 3 gallons of fuel usable left in the tank the light pops up but the first half of my tank goes way slower than the second half. And I doordash all day sometimes and can confirm it's not like in my head the amount of hours I can go from full to half and half to empty are different

 

I think all that is normal. lol

 

I follow the simple and succinct instruction in the owner's manual. Something to this effect:

"Low Fuel indicator": Indicates when the level of fuel in the tank is low... When the lamp comes on: get gas."

I have never seen it come on, but I did put 20 gallons in the tank one time.... (Never again.)

 

I did 20.1 gallons once. Towing a trailer in a 40-50 mph headwind from Spokane to Tri-Cities WA. Stopped at a gas station that was not pumping gas only diesel. Went to the next one and despite my son and wife saying we won’t fit into the station I did it anyway. Got in and out and got a free lesson on tank volume and towing in severe headwinds.

 

Welcome to TW. Your mileage is a little low compared to mine. I have a 2020 TRD Sport with 6 speed manual transmission. I generally drive at or a few MPH under the speed limit, tires inflated to spec, basic stuff. I'm around 22 to 23 MPG on average and have been as high as 27 during the summer.

 

As a wise man once said "I'm gonna give you a fuel line that'll hold an extra gallon of gas. I'm gonna shave half an inch off you and shape you like a bullet. I'll get you primed, painted and weighed, and you'll be ready to go out on that racetrack."