Miles to empty is such a bullchit, useless, unreliable # that I can't believe people still use it. Since it's based on your prior average MPG's (which the on-board can't compute worth a crap) X the # of remaining gallons (which is another wild-azz-guess by the on-board), relying on it to tell you when you need gas is a crapshoot. And if your prior on-board data was based on one driving style such as granny and your current tank is based on driving like you stole it, you'll be scratching your nutz wondering why you're sitting on "E" in the middle of bumfuk.

I can get 26 MPG driving highway, pump-to-pump hand calculated. That would be 416 miles/tank if I was stupid enough to run it that low.

When you get to or below 1/2 tank, consider that it's time to fill up soon and be done with it.

 

I average around 280 miles per tank when I fill up, i typically get gas right before the light comes on and is usually about 14 gallons. On highway only drives I get about 400 miles on a tank!

 

I get about 280-290 but where I live its like 97% city driving so I cant complain. It averages prob like 18mpg

 

I'm no expert here, but I think the computer controls how much fuel goes into the engine, so in essence I would think that is how it calculates how much fuel is used, and uses the odometer to judge the distance... then computes it that way. Never the less... you could do it the old fashioned way which I've done both and found my onboard mile to E to be pretty accurate.

A side note, sometimes when I'm driving it like I stole it and then fill up and drive easy without any resetting... it will tell me like 290 miles till empty, only to find out I drove 360 miles (the computer doesn't always update mid-drive.) So although not perfect, it works to an extent.

 

Also, I am pretty sure our cars keep a gallon in reserve so although it may say 300 miles till empty, you probably have around 320.

 

It has a rough idea how much fuel goes into the engine, but no better than that, that you can count on. There are tolerances for things like injector flow rates, injector 'on' time and opening/closing ramp rates, and fuel pressure, all of which directly affect the amount of fuel used. I find that actual gallons used varies typically between 5% and 10% more than the computer thinks that it has delivered.

The only time that I bother with DTE is when I'm on a trip to/from my Dad's place. 325 miles is a long enough distance to set the beeper off a couple of times but is legitimately a one-tank trip.

Around town, I'll let it drop down below 1/4, and I'll have less than 200 miles in at that point.


Norm

 

Although some of the on-boards are accurate (my g/f's '06 Pony is typically within 0.2 MPG of the hand-calculated value), it seems that the vast majority are off to the conservative side by 1.5 to 2.0 MPG. My "gut" from the input on the forum over the past 3 years is that about 80% or more are inaccurate.

 

when I fill up completely, my tank says I have 230 till empty...it's weird cause one time it said like 300, it never fills up all the way

 

The difference in Miles to Empty is due to the onboard using the average MPG it computed previously x the "guesstimate" of fuel in the tank. Do yourselves a favor and don't even look at Miles to Empty (or whatever it's called).