Estimated MPG Range Question

When I first got my Tacoma the range on a full tank would show like 350-360 mpg. Now every time it’s showing 329 or so. Is this normal? It seems to adjust during driving so by my next fill up I’ve gone that 350-360 mile range.

 

I believe it calculates on the last tank's MPG average.
In other words, if your last average was say 15 Mpg the the range at fill up will be lower. As you drive and get a better Mpg then it will adjust as you burn fuel and ad miles.
If you fill up again and your last average was say 18 Mpg then the Range will be higher.

 

Mine is alwasy wrong with its estimate. Says less than i get.

 

You will find that even the MPG is not quite accurate too. If you want an accurate mileage, you have to calculate your miles drive per gallons filled. The system cannot calculate fuel used while idling it throws off the calculations.

 

Finally I say the same . Sitting at idle kills fuel

 

I've done the actual math for the mpg i'm getting and the trucks computer readout is very close. Usually read around 385...less in winter.

 

I use a scan gauge and the numbers at the pump, those always match.

 

385 to 416

 

Absolutely...especially in the cold Yotas hog fuel at idle. Always have! Fire 'em up and get rolling!

 

It's a rolling average. After towing a trailer and getting 11-14MPGs for about 6 tanks it took about 3 tanks to come back up to normal levels. It's usually never 100% correct and leaves room for reserve fuel if you get yourself in trouble.

 

I've never found this to be true. My MPGs tank pretty hard while idling for extended periods of time. My gauge has always been within a few tenths of an MPG based on manual calculation.

 

Yes, it is calculated on tank usage. If you take a cross country trip, as I did in October of 2019, you will notice the mileage when you fill the tank, will go WAY up because you are just constantly driving on the highway. Mine went to over 400 miles everytime I would fill up during that trip! Now though, it is around 370 or so, whenever I fill up.

 

Mine does the exact same thing. For some reason, it always takes the lowest range I've had. Started similar to you, mid-high 300's for range, towed a couple trailers, never came back up. Same number as you too, stuck right at 329. Only thing that's ever taken the range back up was disconnecting the battery when I needed to do some wiring.

Don't sweat it. Like others said, doesn't actually affect anything, just another quirk of these trucks.

 

My tank average is 17.8 mpg right now. That’s ~320 miles per tank. It goes up some in the summer but it has been consistent for exactly 12 months of ownership now.

I track everything on Fuelly.

 

I just started using it . I like it

 

Op, it will fluctuate. Here's a bit of info from the manual (2020):

Distance to empty

• Displays the estimated maximum distance that can be driven with the quantity of fuel remaining, the distance driven after the engine was started and the distance since the function was reset, respectively.
  • This distance is computed based on your average fuel consumption. As a result, the actual distance that can be driven may differ from that displayed.
  • When only a small amount of fuel is added to the tank, the display may not be updated. When refueling, turn the engine switch to the “LOCK” position (vehicles without a smart key system) or off (vehicles with smart key system). If the vehicle is refueled without turning the engine switch to the “LOCK” position (vehicles without a smart key system) or off (vehicles with a smart key system), the display may not be updated.

The inputs that affect the numbers are:

• Main body ECU
  1. ACC switch signal
• ECM
  1. ENG Display ID
  2. Engine Type Information (1-4)
  3. Engine RPM data signal
  4. Fuel consumption
  5. Transmission information
  6. Gear information
  7. Drive train information
• Skid control ECU
  1. Vehicle speed (SP1)