Faulty Gas Gauge?

Hi, I bought my 2015 5.7L TRD Tundra new, and for the entire time I've owned the truck, have always gotten a low fuel warning with about 20 miles on the projected range. When I've filled up, I've never added more than 22 gallons or so; when the tank was full, the projected range was always ~350 miles.

Last week, I replaced the truck battery for the first time and when I checked the range on a full tank, it was ~440 miles. This caused me to check the gas tank capacity, which was surprisingly 26.4 gallons. When I ran the tank down to 1/8th of tank, I filled up to full with only 19 gallons.

Bottom line: is my fuel gauge under-representing the amount of gas in the tank? Is this a common thing with Tundras?

 

Welcome! May I suggest using the search function on this marvelous website? You will find your answer(s) there.

It's a common thing with most vehicles. My Avalon does it, my Sequoia did it, etc...

 

Run a few tanks through with normal driving. You'll see everything level back out.

Welcome to the forums.

 

Trust the low fuel warning light... it comes on with 5-7 gallons remaining.

The Range calc is worthless. It is not dynamic in how it calculates your range. It uses a past average of ~X00 miles. It won't add miles when going from city miles to sudden highway driving.

If you do a tank of city driving, fill up, then take a long highway trip, you can easily run past 0 on range to empty calc because it won't add miles

 

Welcome from NorCal!

Couple of weeks ago I was doing some trail repair and had to disconnect the battery. Once off the trail I filled up at a gas station. Started the truck and I just busted out laughing when it said I can go 540 miles

Now it’s back to normal.

 

It's been my experience with several toyotas over the years that when the low fuel light comes on you have about 75 miles of range left. So depending on the MPG of your vehicle the fuel leftover will change. On my wife's Rav4 it's a little over 2 gallons, on my Tundra it's like 5-6. on my 2016 4Runner it was like 4 gallons.

 

Toyota has always kept a large “reserve” the best reason I have heard for it is to keep the fuel pump submerged in fuel and keep it from overheating.

The instrument cluster reads a fuel use signal from the engine ecu and calculates instant, Avg MPG as well as range. This data is stored in the cluster and when power is removed from the cluster it forgets it all. It takes some driving but eventually the values will come back to “normal” after some driving