Miles per empty discrepancy

I just filled up my 2017 Tacoma and the "miles until empty" indicated 400+ but I just topped it off at about 3/4 full (I'm in NC awaiting Hurricane Florence) but now it says 367 miles to empty. What gives?

I'm I tripping or have I just misremembered this? I could have SWORN it's constantly read 400+ at a full tank every time prior.

 

How many gallons does your tank hold and what is your historical mpg. You should be able to mentally calculate this on the fly without relying on technology in the truck.

 

Thank you. Yes I understand that. I believe I have about a 20 gallon tank, and get (at least right now about 17-20 mpg) That would (=) about 17/340 or 20/400 respectively

I guess a better question would be if the "miles until empty" indicator fluctuates depending on if the avg mpg changes.

I've never noticed this before but I guess that makes sense. But wouldn't that mean that the "miles until empty" would possibly increase if you drove in city for several miles and then started out on the hwy?

 

Toyota lists it as a 21.5 Gallon tank.

Mine almost always starts with 385 on DTE. Once, it started with 405.

 

With SWMBO's previous car I used to do mental calculations to figure how much gas was in the tank, based on displayed mpg and displayed range. The answers never made sense between calculations several minutes apart on the same tank of gas. Now I take those numbers with a generous dose of salt. I figure the mpg and range readouts are very rough guidelines, not something to be relied on.

 

So does the "miles until empty" change as your mpg change? Effectively meaning your miles per empty could go up as you drive? So if you drove in city for several miles and then started out on the hwy would your miles until empty change?

 

My max is 397. So frustrating
My OCD can’t handle that random number

 

Mines never said 400 on a fill up. 340-360

 

Ive never seen it go up. In 40k miles, the DTE doesnt go up regardless of MPG

 

It does.

 

Yes. As you drive, the "miles until empty" will change based off of what the computer calculates as the current mpg.

 

Thanks everybody! Wish us safe travels and god speed here in NC! Cheers!

 

HA HA HA you guys with your fancy "miles till empty" displays.

I drive until the gauge is below the empty line. That means I have 20 miles left!