Running on empty
 

Is it realistic? I've filled the tank when the needle was in the red - it wasn't bone dry I had 10 miles range left.

When the needle was in the red (not rock bottom) I filled up the tank until the auto-stop.
I set the trip meter to 0 and commuted until the needle is back in the red, the in-car computer showed I had 10miles range left but I decided to fill up rather than completely run out trying to get to the next station on route.

I took the reading of the trip meter - 641.6

I understand that this isn't running the tank dry but it's unrealistic to do so. Does this mean I'm getting correct information, as my readings on Fuelly look too high!

On an average drive to work my car computer says I'm getting 55 - 60 (all pretty much A roads) however Fuellly says my best MPG is 74.3 ?????????

Am I doing this correctly?

Many thanks

It doesn't matter how much fuel you have left in the tank. What matters is that you should fill up to approximately the same level (first click, close to the brim, anything you consider "full"). The more fuel used from a tank the better the accuracy, so - in a way - it's good to run close to empty.

But sometimes I fill up earlier - when, for example, I wanted to separate the 48-hour run tanks from the commuting/touring ones before and after. I still aim for the same 'full' level.

I used to run it right down until the last light went out. But then I ran dry and my engine cut out, luckily I managed to roll into the petrol station. As said, you dont need to run it right down, but filling up is such an expensive task, I often let it run right down anyway. When I fill up, I wait until I can see fuel resting in the filler so I know I cant get anymore in.

I usually try to fill between 1/4 and 1/2 on the gauge. In winter I try not to let the tank get below 1/2. I have let the tank get to the "Low Fuel" warning, at about 1/8 tank, just to see if the warning worked. But I have no faith whatever in the accuracy of any system that will tell me I have only ten miles of fuel remaining.

My fuel light comes on when the distance to empty (range) meter reads 50 miles (2 gallons left the way I drive).

I've read that filling beyond the gas pump's automatic shut-off can damage a car's emissions control systems.

2013 KIA Soul!

Overfilling the fuel tank is alleged to cause liquid gasoline to make its way to the charcoal canister used to adsorb fuel vapors and keep them from getting into the atmosphere. I do not know what damage, if any, that might cause.

Running the fuel tank to empty is said to be bad, because the in-tank fuel pump is fuel-cooled. Absent the usual covering of fuel, the pump can become hotter than normal. In the case of diesels, running out of fuel can result in an inconvenient episode of bleeding the fuel system before the engine will run again.

i just bought a new 2013 smart fortwo car and found this site by luck with searching information through yahoo. I want to say great work with this site and thank you for building a shared program we can all see online by the inputs we send in.

John

Tempe AZ USA

Been overfilling mine and running on fumes for the last 50,000 miles with no problems yet. Dont beleive everything you hear...

Small partial fills result in big errors in the consumption figure. My car has about 15 litres left when the warning light comes on. I usually try to fill up after that. If I have to do a small top up I would prefer to add it to the next fill rather than enter it as a fill on its own and have an unreliable result. Also I always try to fill to the limit I can get in. This is probably safer with a diesel.

15 litres?! Thats loads, 200 to 250 miles in a normal car. Mine comes on at 5 litres, but considering my car isnt that good on fuel, I usualy only do another 40 or 50 miles before filling up.