For a couple of days I have been putting off filling up. Yesterday I saw the mileage remaining display go to --- . At that point I decided I really needed to fill up at the next station. Well the next station was 5 miles later and the car took 16.888 gallons. I read today that the tank capacity was 16.9. Is that right? Was I that close?

 

Not sure about total capacity but it looks like you were awfully close.

I had a similar experience in my old Audi S4. After the display read 0 miles left on the tank I had to drive another 12 miles for gas. I was running late for a bike event and didn't want to stop before.

I haven't gotten anywhere near that since. I read somewhere that tanks often have sediment at the bottom and sucking that last little bit of gas can also introduce that sediment into your fuel system. Sure the fuel filter "should" catch it but would rather not tempt fate again. Also, if there is any water in the tank you would likely take that in too and the fuel filter will not stop water.

Cheers

 

meh, I've pulled a lot of tanks and never seen sediment on a modern car without a rusty tank. Further, the fuel pumps generally have little sock filters on them that should prevent any harmful sediment from making it to your fuel system.

 

You're luck Nebraska is flat - any incline and you would have stopped.

 

Did that once before too. I don't recall the exact amounts, but I do recall that I put more fuel in than the stated capacity of the system. But I didn't run out.

Last summer I ran out of fuel on my boat about 50 feet from the fuel dock and coasted in to the dock. Filled up with 127 gallons to fill my 125 gallon tank.

Seem fuel capacity is a bit understated. But not good to cut it so close. I'm obviously pressing my luck.

 

Thanks for the information Quadcammer. I think what I read was pretty old and not based on recent experience. Good to know.

 

... or fuel vendor's fuel meter is not calibrated. It seems that the deficit is always for the buyer.

 

I believe the stated capacity is for the tank. The filler tube probably holds another 1/2 gallon or so, depending on the size of the tube...

 

From the 2007 Owner's Manual:

911 Carrera, 911 Carrera S: approx. 16.9 U.S.gallons
911 Carrera 4, 911 Carrera 4S, 911 Targa 4, 911 Targa 4S: approx. 17.7 U.S.gallons

In my C2, after many observations, "60 miles remaining" seems to indicate that my fill up will be approx. 13.7 gallons. Hence, given the 16.9 gallon tank capacity, I've got 3.2 gallons in the tank and theoretically approx. 70 more miles of driving as long as I stay on a flat road. That said, I always fill it up within 10 miles of the "60 miles remaining", if not sooner.

 

In your case you may have managed to get 16.888 gallons into the car's tank by filling up a portion of the fuel tank filler tube.

Most I've ever managed to get in one of my car's tanks is 15.66 gallons with the state capacity of 16.9 gallons. This car doesn't have an on-board computer so I can't say how many miles were remaining.

These modern gas tanks do not produce much trash and generally the incoming fuel is pretty clean. I had the fuel pump in my 02 Boxster finally quit (at around 200K miles) and the only fuel filter is a fine mesh that is part of the fuel pump housing and while this mesh had trapped some trash there wasn't much considering the pump pumped maybe 8000 gallons of fuel during its service lifetime. BTW, the pump attaches to the bottom of the tank and the pump's intake sits less than an inch off of the tank's bottom.

The tech who replaced the fuel pump at my request looked into the tank with a bright flashlight and reported very little trash in the remaining fuel and no signs of any water at all.

The real concern from running the tank real low on fuel is that the fuel pump overheats due to a lack of enough fuel to keep the pump cool. While I never saw the pump in operation it appears to me the pump redirects some fuel into circulating around inside a false housing and this helps cool the fuel pump. The pump proper is about the size of a beer can and is made from of a heavy walled aluminum material. The pump is not designed to be disassembled.

While I doubt a healthy pump would die upon just one exposure to running the tank low on fuel, over time and after multiple instances of doing this the fuel pump's life could be shortened.

Another risk is if the car is left sitting for a long length of time the fuel can go stale and stratify and the lousiest fuel layer could be at the level the fuel pump would suck in and in doing so and routing this lousy fuel to the injectors this could damage the injectors.

Sincerely,

Macster.

 

It's obvious no pilots particpating in this thread. Never want to see a low fuel light.

 

Precisely! It's good practice never go below 1/4 tank.

 

Hadn't thought about that. Good point, as usual, Macster. Ambient temp was below freezing so hopefully that helped. Nonetheless I am resolved not to tempt fate like this again.

 

I've hit the triple dashes at least half a dozen times or more in mine. It appears to go from an actual digit to "---" when you go under 10 miles remaining.

Never experienced any problems with the fuel pump, but I'll specifically ask them to manually check it out when I take it in in a couple of weeks and report back.

 

That is interesting. Temperature correction has an impact on fuel volume.

Gas pumps in Canada are temperature corrected by regulation to 16 degrees celsius, around 68 degrees F.

I don't know what the routine is in the US, but I imagine it's the same.

The wild card here would be the temperature correction value used by Porsche in defining fuel capacity.