Stelvio Reserve Tank

[DonTom]

2016 MG Stelvio. What is the "reserve tank" ?  I don't meant the size of it,  I mean how do I know when I am on reserve?  The owner's manual doesn't seem to mention it. On my older bikes that have a reserve, it runs out of gas on the main tank and I have to switch to reserve. What about on my new 2016 Stelvio?

-Don-  Reno, NV

[smdl]

Hi, Don.

There is no reserve "tank", although there is a low fuel light that comes on to warn you when you are getting low.  Only trouble is that it seems to come on really early.  When mine comes on, I only seem to be able to add about 21 liters to the 32 liter tank.  So, no need to worry too much about immediately refueling when the light comes on.

Cheers,
Shaun

[DonTom]

Hi, Don.

There is no reserve "tank", although there is a low fuel light that comes on to warn you when you are getting low.  Only trouble is that it seems to come on really early.  When mine comes on, I only seem to be able to add about 21 liters to the 32 liter tank.  So, no need to worry too much about immediately refueling when the light comes on.

Cheers,
Shaun

Shaun, I think you're saying that  I am on the "reserve tank"  when the light comes on. And even when it does, I am good for about 100 miles. Does the fuel gauge still have a reading while on "reserve" with the warning light on?

-Don-  Reno, NV

[Daniel Kalal]

Don,
I've ridden quite a few different Stelvios, over all the different model years.  That fuel gauge works, but you should really calibrate it yourself--fill up when only one--or two--or none--bars displays.  These bikes are not the same from one to the next (the float setting is evidently pretty fussy), but each seems consistent in itself.  You'll soon enough know how far you can  ride on 32 liters and that's the number you need to keep in mind.

Very (very) roughly, when the light comes on you can divide how far you've gone by two, and that should take you to empty.

[pete roper]

Does it use a float Daniel? I though it was a thermistor that triggered the light?

[Daniel Kalal]

Does it use a float Daniel? I though it was a thermistor that triggered the light?

My Daytona has a thermistor for the light, but the Stelvio has a float--does it also have a thermistor?  Anyway, the float has tiny feelers that scrape along connectors--it looks a sketchy design.  I've seen a couple of different designs for the Stelvio float system, both with the same part number, which isn't encouraging.  Mine had to be changed out twice under warranty, which  is why I've had these things in my hand.  Somebody else can chime in if there's some two-part system to the light and fuel gauge bars that I've missed.

[Jim Rich]

I don't trust the low fuel light or the gauge.  I just reset the trip meter and know from experience how many miles I typically get from each tank.  I miss the reserve tank petcocks of the old bikes.

[DonTom]

Does it use a float Daniel? I though it was a thermistor that triggered the light?

Since thermistors  will only change resistance with changing temperatures, how does that work for measuring fuel level?

-Don-  Reno, NV

[Kiwi_Roy]

Since thermistors  will only change resistance with changing temperatures, how does that work for measuring fuel level?

-Don-  Reno, NV

The thermistor is normally kept cool by the fuel, once uncovered it starts to warm up, the resistance drops and it draws more current creating more heat until it drops low enough to turn on the low fuel light (~1oo milliamps). It really operates at a fixed point about 5 inches from the bottom of the tank but the one on my VII Sport sort of slowly comes on as the fuel sloshes around in the tank, when I see this I have about 40 miles to go, once it comes on solid and won't go out with acceleration or braking then I start to worry.
I don't think it was used much beyond about 2004.
The main problem with the earlier ones owners would mix the plug up with the electric petcock and as soon as it became uncovered the straight 12 Volts would turn the thermistor into a flash bulb, later bikes had the plugs polarized so you couldn't mix them.

[DonTom]

Don,
I've ridden quite a few different Stelvios, over all the different model years.  That fuel gauge works, but you should really calibrate it yourself--fill up when only one--or two--or none--bars displays.  These bikes are not the same from one to the next (the float setting is evidently pretty fussy), but each seems consistent in itself.  You'll soon enough know how far you can  ride on 32 liters and that's the number you need to keep in mind.

Very (very) roughly, when the light comes on you can divide how far you've gone by two, and that should take you to empty.

Is the entire 32 liters (8.45 US gallons) usable? I know on some bikes you can "run out" of gasoline with almost a gallon left in the tank.

-Don-  Reno, NV

[pyoungbl]

Don, I have put 8 gallons in my 2012 Stelvio NTX and the bike was still running just fine.  I try to avoid running so low on fuel, mainly because the fuel pump is cooled by the fuel.  Since the fuel gauge is not 100% accurate (consistent yes, accurate no) I rely more on the trip odometer.   I have a pretty good idea of how far I can go before I'll need about 6.5 gallons of gas.  Reset the trip odo when I fill up.  Through experience I know how many miles I can go before the 'low fuel' light comes on.  This is a double check on my mpg for a trip.  I do the double check because the mpg can change significantly due to wind or rain.  Why rain?  The evaporative cooling will fool the ECU into shooting much more fuel into the engine, your mpg will go down quite a bit for that tank of gas.  If I anticipate 240 miles before the low fuel light and I only get 200 I know that I'm burning more gas than normal.

Peter Y.

[stormshearon]

Something else to keep in mind - at least this is how my 2014 works - when the computer thinks that you are really on reserve (occurs after the low fuel light is on) the trip odometer starts counting miles to empty, not miles driven. I have only seen this a few times when running the bike really low on fuel as I usually try and fill up after using about 6.5 gallons. The several times I have  seen this I had a bit over 300 miles traveled and a bit over 8 gallons needed to fill the tank.

[pyoungbl]

Stormshearon, the countdown is not miles till empty...it's miles gone since the computer thought you were on reserve.  You will see the numbers getting larger as you ride along, not getting smaller as you get close to empty.

Peter Y.