So, just got back from a trip out to Banff with the wife for the anniversary. Not a bad trip, 3000km round trip, but on the way out, I found the answer to the above question. I know there has been talk around here of what kind of mpg this car gets, how far can it go, etc.. Well, I didn't run out, but here was the situation:
Just got to Moose Jaw and the fuel light came on, still said I had about 40km left, plus reserver fuel. Decided to keep going and fill up in the next town (easier and less time consuming in smaller town) which was 15km away. Got to it, no services, okay, next town (20km) got there, again, no gas. Next town, well, you get the idea. So, finally the car says 0km left, alright, I'm in the reserve, 5 liters I believe. Next town comes up, guess what, yep, no gas. So, I have now been driving for 80km beyond the 0km mark, getting a little scared now as I am in the middle of nowhere. Sign to next town 30km, get there (really scared now) and yep, no gas. Next town is another 30km, no choice really, have to go for it! Get there, and THEY HAVE GAS!!! No premium though, but he told me the next town does have so I put in 10 liters and filled in the next town (and the whole can you run regular in this car without issue question: yes you can! ) Anyway, filled up in next town 10km away. Here are the numbers:
10 + 62.6 = 72.6 liters, took about 1 liter to get from the first town to the second town so 71.6L in the tank to fill. Now I don't know how much the filler neck holds, say 2 liters, that gives a grand total of 69.6 liters in the tank. With a total tank capacity of 69.5L, I'd say that I was running on air for the last few km's. I could feel it coughing on the last two hills the car had to climb. And the total distance, 749km (468mls) at an average of 127km/h (80mls/h). Not too bad on fuel economy eh! And when I decided to slow down after about 100km beyond the 0km remaining mark, to about 100km/h, I was getting 7L/100km (34 US mpg) (according to the car) I bet that car could do over 800km at that speed, but I'm not going to test that theory.

ps. If this happens to you, DO NOT let your wife know, especially after she said 150km ago "Why don't you just fill up in Moose Jaw?".

 

So, in summary ...

on your anniversary, your wife added "not stopping for gas" to "won't ask for directions" as a male trait

 

WinterJag - Very interesting. So that's "stress testing"!

 

Well, I actually do ask for directions if needed, but usually I just use the nav! But I will not do the gas thing again. From now on when we do those kind of trips I will fill up when I get the chance. It just happened that I got to the stretch where there is no gas for a while, for the rest of the entire trip there were gas stations every 15 min or so. But, now I know to fill up more often! It was very stressful for that last 60km. I was constantly doing the mental math with the mpg readings and how far and how much gas should be there etc. and adjusting my speed to stretch it to the next town. In the end, all is well, its actually a good story! But, to anyone out there who ends up like me and is stuck out there on empty, you now know how far you will be able to go!

 

Hopefully there wasn't any scungy (technical term ) stuff at the bottom of your tank that got sucked up into the fuel filter or the engine. Your trip however does shed some light on why I've had the impression that the fuel tank in my STR seems very undersized. Sounds like it is actually bigger than it lets on and "E" really isn't all that "E"......

At least that's my take on your post, of which 90% I don't understand because the metric system may as well be sandskrit to me.

 

Maybe that explains the 34 mpg too. I'm not sure how one gets 10 more mpg than I do on long trips. Maybe the moose helped out?

 

Maybe it was the moose! To help with the km to mls stuff, I used the button that switchs from L/100km (Canada) to US mpg. That's where the 34mpg comes from, and the best I saw was at 100mh/h (60mls/h), 36mpg! Now I know the car computer is a little off on numbers, but when I calculated everything out with actual distance and volume of gas, it came to about 9.4L/100km on the way there, the car said 9.1L/100km average (thats about 26-27 US mpg). So at least for my car it seems fairly accurate! I bet with an average speed of around 70mls/h or less you could get over 500mls on a tank. I don't think E is really E either, as I managed to put almost 100mls on the car after it said 0km/mls left. As for how big the actual tank is, who knows. As far as I know there is supposed to be 5 liters in reserve after the car says 0km left, but when I put in the 10L at the first place, it still said 0km range, so, that is double what was supposed to be there. For all I know there could have been a few liters left in there, but I'll leave that test for someone else!
As for scungy stuff in the tank, I didn't notice anything for the rest of the trip there and back, ran as smooth as ever. Maybe my tank is clean, or as I suggested above, maybe there was still lots of gas left and Jag really just guessed at the tank capacity! Maybe it's really an 100L tank!

 

Hmm - insightful stuff. Sounds like you carefully collected data along the way. I haven't come all that close to 30mpg myself, more like 24 to 26 at best. I figured with the fat tires on this thing getting anything better would be hard to do even if you were light on the throttle.

I wish the highways were empty enough around here to average 80mph. I'd have to do a lot of runs up to 150 to counteract all of the trucks and idiots that ride in the passing lane at 55mph and impede everyone.

 

Great story, WInterJag...and absolutely no offense intended...but the above is a statement I hope my wife never has occasion to utter....

 

Moose Jaw: town in Saskatchewan! I assume that is the part you didn't understand!
Come on, don't you know all the towns in Canada! lol

 

And a welcome from SoCal...hope you enjoy it here.
One word about running on empty, as you know, the fuel pumps are internal and rely on the fuel to keep them cool. If the gas level gets below them, they'll get hot and can malfunction.
I'm positive that's what happened to me about 2 1/2 years ago, just after I got mine. I'm positive the previous owner did just that which caused the gas guage to flip flop from 3/4 full to 3/8 full even though I filled the tank just prior to noticing it happen.
It was under factory warranty and didn't cost me anything, but out of warranty, a Jag dealer will want $800-$1,000 to fix it.
DIY will obviously be cheaper.

 

Winter jag, good write up you hoser! There are times I do admire my 03 STR's economy compared to that of my 205 hp. 4.0 V6 97 Ford Explorer. A "Mafioso" air intake elbow will likely give ya one or two MPG more.

 

I knew Moose Jaw was a burg somewhere in the great North...but not specifically Saskatchewan...thanks for furthering my education! No....all I meant was I hope to never ever be caught that far from the serious southern heat of TX or heat + humidity of FL and running low on fuel and ideas whilst simultaneously receiving unsolicited advice from my wife!

 

If you have a Canadian spec car (like mine) and switch to non-metric display, the MPG is in Imperial miles per gallon ,not US miles per gallon. That's why our cars appear to do much better on fuel consumption.

 

Ah! I didn't realize that it switched to imperial, not US mpg. Still, pretty good numbers either way! I know people with 'economy' cars that only get 5-10mpg more than me. When they hear what I get, and the type of car I have, they don't really like it! They all say they would give up 5mpg for a Jag!

As for running the tank that low and the overheating the fuel pumps, it was actually a cool wet day when we drove out. Also, I know you can hear the pumps whinning (or some kind of noise) when it gets really low, and I didn't hear anything. And lucky for me, my wife was actually asleep for the majority of the "nrevous" driving. She fell asleep just after Moose Jaw and woke up about 20min before I finally found gas! But those 20min were interesting to say the least! I think if I had run out she would have just got out and walked home!

 

But I also think the 34 you originally quoted was an instantaneous reading and not an average. It was 24-26 average right? Which is almost 1.5 mpg better than what I see. Probably imperial mileage then ...

Or you could just go with the Moose juice story ... Fill ups must be a b*tch though.

 

I would agree. I frequently see 34-36 or it's metric equivalent on mine but only while in steady state cruise. A bit of city driving drops it off considerably.

Still pretty good considering the weight of the car and size of the engine.

 

The good thing is that the fuel pumps can't be working hard when you're trying desperately to keep fuel usage low. So they shouldn't have been getting hot.

I'm not so sure that would be true when you're running on fumes!

I think someone mentioned the risk of sludge or the like at the bottom of the tank but don't the pumps suck from there all the time in these cars.........

 

Yes, but as fuel diminishes, the concentration of "tank sludge" increases, making it more likely that you're pulling more debris into your fuel filter than you'd like. So the argument that running your car on a nearly-empty tank increases the likelihood of creating a fuel sludge issue is a valid one....

 

Somebody please explain to me why 'tank sludge', assuming there is such a thing, would sit in the bottom of a tank and never get sucked out along with the rest of fuel through normal diving.

I seem to remember that cars go around corners, stop, start, go over bumps etc. all of which would mix the contents of the tank pretty thoroughly.

Being that tanks drain from the bottom, and that's where the supposed crap resides-why is it not the first to go and not the last?