So I'm still getting to know my new car (2012 G37x), I'm only on my fourth tank of gas and this is my first car with the Range or Distance to Empty feature.

Anyway, I get into my car after work the other day and had around a quarter of a tank of gas left. I was running a bit late and just wanted to get home and didn't feel like stopping for gas. So I check the range display and it says I have about 60 miles to empty. Now its 18 miles between my house and work so I figure I should be able to get home and back to work and then fill up before heading home the next night. When I get home it says I have 41 miles to empty. So I'm thinking I should still be good to go.

I head out in the morning and the low fuel light pops on before I even get a mile down the road so I switch the display over to the Range screen and it says 35 now. Hmmm, that is weird, I'm thinking. Over the next 2 miles of the drive it drops from 35 down to 22. Well now, I'm starting to get nervous. By the time I get halfway to work the Range is at -- and I'm thinking I should stop REALLY soon. Its about 3 more miles to the next gas station and I'm hoping I can make it. I did make it and put 18.12 gallons in the tank. Now I thought I read somewhere or someone told me the gas tank on this car was 18 gallons and I'm thinking "Whew, I'm never going to push it like that again!"

When I got to work, I checked the owner's manual and according to it the gas tank is 20 gallons so I would have, in fact, made it all the way to work and back to the gas station after work. And I wasn't running on fumes pulling into the gas station that morning like I thought all the rest of the way to work. Boy, it was unnerving to think I was that low on gas...

 

There's tons of posts about this.

Cliffs: DTE is not particularly accurate. It is dynamic and will show a longer distance if your recent driving is at higher mpg, less if its at lower mpg. DTE figures include anywhere from 2 to 3.5 gallons of reserve fuel left in the 20 gallon tank.