In the owner's manual, it says under Filling Quantities: "17 gallons with a reserve of approximately 2.1 gallons (vehicles with PDK) or approximately 2.6 gallons (vehicles with manual transmission)".

Does this means that there is a separate reserve tank that comes into play when the main tank is nearly depleted? If not, what does reserve capacity mean and what practical use does it have? In other words, if the total tank capacity is 17 gallons, why does it matter that there is a reserve of 2.1 or 2.6 gallons? Is it only that the low fuel warning light comes on when the tank reaches these levels?

 

Yes to your last question. The last car I worked on that had two gas tanks was a Jag and you flipped a switch to go from one to the other on your way to the airbase where your Spitfire awaited

siberian

 

Well . . . that and the Gauge will indicate "0" in the red zone.
.

Artists rendition.



Low Fuel Symbol. Arrow points to the side of the car the fill point is located.

 

Funny, I am a fill it at half empty guy. I have never seen this!

 

I like that it automatically brings up nearby gas stations in the navigation when the fuel level gets low.

 

Did you experience it or read it?

siberian

 

Oh yes!
.

 

I'm the 3rd kind; as I typically drive my brand new car on it's first tank of gas (while the gas tank is nice and clean) to the point where the low fuel light comes on so I *KNOW* exactly what I'm dealing with when it warns me. I don't remember exactly how much was left (16.9 - what it took to fill up) but it was close to 2.5 gallons left (I have MT) so close to 50 miles before you're walking. I do this primarily because of the mountains I tend to drive in sometimes don't have a lot of gas stations (basically few and far between) and I need to be cautious if I'm exploring new roads that I'm not familiar with.

I would have definitely optioned the larger fuel tank if I could have on my 2020 992.

 

So, the question remains... is the gas tank 17 gallons plus a 2.1 gallon reserve? Or is the reserve (whatever that means) part of the 17 gallon tank?

 

Part of the 17 gallons, however it is said that consumption and fuel left are always very conservative and you may actually drive a wee bit further than advertised. Personally, I don't chance it.

As to running it down so you can be absolutely certain of how far you can drive, is a sure way down the road to suck accumulated crap in from the tank and overheating the fuel pump.

siberian

 

Yes, I agree that you should never run the fuel tank to near empty. I was just curious about what Porsche means when they use the word "reserve".

 

On Porsche instructions manual says: tank capacy16.9 gallons . For sure do not include the reserve quantity.
In my experience I drained 100% the tank in order to swap to E85 fuel.
It took 19 gallons to fill to top off .

Porsche Carrera T 2019 (991.2)

 

I just want to get it to below 1/4 so I can see if the damn rattle stops or is not as loud as you definitely don't want to run the tank anywhere near empty given deposit at bottom and fuel pump.

siberian

 

Wait - what? That sounds scary -- our Porsche's know how to deal with E85? What's the benefit?

 

Question when filling up: I usually drive until it shows less than 20 miles or less left in my tank because I live in a densely populated area that has a large number of places to get gas. When I go to fill it up, it usually 'stops' filling after I've pumped somewhere between 14-14.5 gallons of gas. When I say stop filling, I mean the pump handle pops and I have to squeeze again to start the gas flowing again. When that first stop occurs, and I start it again, I usually can fill another .75-1 gallon before it pops again, and then I can usually fill a little more one more time, totaling close to 15,5 gallons pumped. I'm trying to figure out why the handle pops when I'm filling when the tank can clearly take 1-2 more gallons. I guess I'm also assuming that the distance remaining includes the reserve and that I'm down to about a gallon when it says 20 miles left. Naturally I don't want to overfill and have gas shooting back at me, but I'd like to get as close to a full tank as I possibly can. Next one I'll get the extended size tank...