I know this was a problem in my 08 GT and figured they fixed it by now but when I brought the car home the first day it read 320 or more miles to empty, can't remember. Now every time I fill up it just seems to get lower and lower. It reads 200 miles to empty on a full tank. Any idea on how to fix it or should I just take it in?

 

I thought that you just manually reset the computer at each fill?

 

I am not sure, all I know is it's reading less and less at every fill.

 

It's because of your driving style. The computer adjusts based on your recent MPGs. If you drive a tank or two of just highway driving, I bet your estimated miles to empty will get above 400. So, long story short...to get it to go back up: easy on the pedal.

 

Haha.. Guess that makes sense then. Thanks.

 

200 miles to empty is a bad thing? Heck, mine says 180 miles to empty if I'm lucky when I fill up. Of course, I don't drive on the highway, and the engine is always revving a lot.

 

The one in my Fusion and Escape were pretty accurate. I never ran out of fuel, but when the MTE got down to 10 , I put like .1 gallons less than capacity in the Fusion.

 

The Miles to Empty (I read) was always based on a rolling 500 miles.

So.. No need to reset on your own, and also, you'll just need to build up miles to get more accurate readings, which I believe the manual says to do.

When I was traveling on my 07 GT, I was getting over 400 MtE

 

it calculates the number based on a average of the last several igintion cycles.

 

I just got to thinking about this some more, 200 miles to empty on a 16 gallon tank is only 12.5 mpg!

Wow! I'd be pretty unhappy if that was all my car was getting, even considering a little bit of romping on the loud pedal...

Have you been calculating the MPG when you fill up?

 

There's an MPG indicator in the info center and it's based on driving habits as well...

 

No, not accurate enough.

If you want to know the true MPG you have to calculate it on fill up.

 

the "miles to empty" on my VW tdi always shows less than what it ends up at when i fill up so i'm not sure what it's calculating at that time

for ex.
at fill-up it will show around 565 MTE
for the next 100 miles of driving it will fluctuate up or down about 15-30 miles
at around 400 MTE i will usually have driven +/- 300 miles
i end up filling up at around 625-660 miles driven and again it will show around 565 MTE at fill-up

you guys should just reset the tripmeter at every fill-up and see what range you get after a few full tanks

 

That is true. The MPG guage on the Vette is super-accurate, always within 2 tenths of one MPG of the manually calculated figure.

On our MKZ, it is usually quite a big high. True MPG is always lower than gauge indicated, often as much as 2 MPG.

 

I was worried about that too at first but I noticed that as I got closer to 500 miles, gas mileage went up gradually and miles to fill up went to 300+. Right now my est. gas mileage is at 17.8. I drive about half city and half highway going to work and I have a tendency to have a lead foot at stoplights.

 

I will play around less and see what I get. About to hit 1000 miles so I guess I can start holding back on the fun a bit.

 

Doing it manually is less accurate, IMO.

even if you take the EXACT numbers (gallons to 3 decimal places, mileage can only get to the tenth accurate), you still don't know if last time the tank was filled to the same point compared to your next fill up.

If anything, you need to measure gallons used and mileage over at least 3 fill-ups.

The computer knows EXACTLY how much fuel is consumed over an EXACT distance.

 

Yep to bad the info center consistently reads 1.4-1.6 mpg less per tank. Thats over the last 4 tanks. If we assume the Info Center is consistent just not accurate then my manual fill technique is good enough to get within +/- 0.1 mpg.

However since the Info Center reading is not corrected for specific gravity of the fuel and temperature variations at fuel purchase then I highly doubt its very accurate when discussing mpg so I cant really use it to prove my technique is good or bad.

Over a years time I will put more faith in miles diveded by gallons than a PCM which is off approximately 7% (I will give you that it could be 6 or 8%).