Ran out of gas.....with a Scangauge II

[nc-grayson]

First and foremost, I'm taking responsibility and making it clear that this was entirely my fault, nobody to blame but myself. First time I've ever run out of gas in my driving years. Lesson learned. Warning: this may ramble on. SIA.

Yesterday I ran out of gas on a back roads 2 lane highway. Like I said I've never run out of gas before, but I knew what it was instantly.

I'm ultimately to blame, but I can't help but think that there's got to be a way to drastically improve my Scangauge II mpg/avg/tank to empty numbers.

I've never pushed the truck this far on a tank of gas, but judging by what the SGII was telling me, I had plenty of fuel to get to the next gas station 1 mile away.

Heres the details of what the SGII read as I was pulled off the side of the road contemplating my options:
Tank: 301 Miles
Gallons to empty: 1.7
Miles to empty: 33.2

I knew it was low on fuel, there's no denying that. But I never thought the SGII would be so far off in respect to gallons and miles to empty. I really was aiming for the next gas station 1 mile up the road.

Hoofed it, bought the 2 gallon red can, put 2 gallons in the truck, drove back to the station, and filled up. (FYI walking through dirt and weeds on a busy 2 lane highway, in your work Cole Haan's isn't cool)

Filled up with 15.5 gallons letting the pump stop itself automatically, resulting in total fill of roughly 17.5 gallons.

The confusing part is my SGII itself when it comes to fill-up procedure. In the year I've been tracking it with the SGII, I have ALWAYS had to adjust "up" the amount of fuel I filled during a "fillup procedure" by a lot. After adjusting the fillup procedure up almost two full gallons yesterday after I actually did fill up the tank, the SGII correction moved from 16%-18%. Meaning the SGII really only thought I could fit 15.5 gallons, but actually it took 17.5 to get there.

On my 100 series, the fillup procedure "estimate" is practically spot on every time over the same year or so of fillups. With the 100, the SGII estimates usually within 1/10 of a gallon of actual fillups. Not the 3rd gen. 3rd gen is ALWAYS at least 1.5 gallons short, making the scangauge gas correction percentages continually increase, every fill up.

I have reset my SGII 3 times now to "out of the box" settings according to the directions in the manual. I've done 3 times in the past because the SGII has always been multiple gallons off on trip/tank gauges. I have followed the 1st and 2nd fillup procedures from the manual every time after a reset. And every single time I've reset it, the fillup procedure always seems to remember the last fuel adjustment percentage...it's never really re-set itself to 0 for the first/second tank. Tank size set to 18 gallons, but it always underestimates how much gas I've actually used. To give a frame of reference, my 24 mile commute to work today, (70/30 hwy/city), the SGII thinks I averaged 23.4 mpg on the way here. So something is, and has been, way off.

Whats the deal? Do I have a busted SGII? Or am I doing something wrong? Or is it a truck issue with the fuel sender or something else?

Sorry for the rambling post. I trust the SGII in my 100, but now I'm not so sure about the one in my 3rd gen.

No lift, stock tire sizes.

 

[JayRolla]

First and foremost, I'm taking responsibility and making it clear that this was entirely my fault, nobody to blame but myself. First time I've ever run out of gas in my driving years. Lesson learned. Warning: this may ramble on. SIA.

Yesterday I ran out of gas on a back roads 2 lane highway. Like I said I've never run out of gas before, but I knew what it was instantly.

I'm ultimately to blame, but I can't help but think that there's got to be a way to drastically improve my Scangauge II mpg/avg/tank to empty numbers.

I've never pushed the truck this far on a tank of gas, but judging by what the SGII was telling me, I had plenty of fuel to get to the next gas station 1 mile away.

Heres the details of what the SGII read as I was pulled off the side of the road contemplating my options:
Tank: 301 Miles
Gallons to empty: 1.7
Miles to empty: 33.2

I knew it was low on fuel, there's no denying that. But I never thought the SGII would be so far off in respect to gallons and miles to empty. I really was aiming for the next gas station 1 mile up the road.

Hoofed it, bought the 2 gallon red can, put 2 gallons in the truck, drove back to the station, and filled up. (FYI walking through dirt and weeds on a busy 2 lane highway, in your work Cole Haan's isn't cool)

Filled up with 15.5 gallons letting the pump stop itself automatically, resulting in total fill of roughly 17.5 gallons.

The confusing part is my SGII itself when it comes to fill-up procedure. In the year I've been tracking it with the SGII, I have ALWAYS had to adjust "up" the amount of fuel I filled during a "fillup procedure" by a lot. After adjusting the fillup procedure up almost two full gallons yesterday after I actually did fill up the tank, the SGII correction moved from 16%-18%. Meaning the SGII really only thought I could fit 15.5 gallons, but actually it took 17.5 to get there.

On my 100 series, the fillup procedure "estimate" is practically spot on every time over the same year or so of fillups. With the 100, the SGII estimates usually within 1/10 of a gallon of actual fillups. Not the 3rd gen. 3rd gen is ALWAYS at least 1.5 gallons short, making the scangauge gas correction percentages continually increase, every fill up.

I have reset my SGII 3 times now to "out of the box" settings according to the directions in the manual. I've done 3 times in the past because the SGII has always been multiple gallons off on trip/tank gauges. I have followed the 1st and 2nd fillup procedures from the manual every time after a reset. And every single time I've reset it, the fillup procedure always seems to remember the last fuel adjustment percentage...it's never really re-set itself to 0 for the first/second tank. Tank size set to 18 gallons, but it always underestimates how much gas I've actually used. To give a frame of reference, my 24 mile commute to work today, (70/30 hwy/city), the SGII thinks I averaged 23.4 mpg on the way here. So something is, and has been, way off.

Whats the deal? Do I have a busted SGII? Or am I doing something wrong? Or is it a truck issue with the fuel sender or something else?

Sorry for the rambling post. I trust the SGII in my 100, but now I'm not so sure about the one in my 3rd gen.

Ive never seen over 250 miles on a tank even on the highway and running her to maybe .5 gallon left. Never seen over 19mpg either. Ive never fit anymore than 16 gal. With a 16 gal tank you used up all your reserve. Trust the gas gauge, not your scan gauge. Mine shows empty with maybe 2-3 gal left. That way I never run out.

 

[jgue467]

My Yellow Low fuel light in combination with the trip odometer has Never let me down. As soon as the low fuel light comes on, I reset one of the odometers.

Knowing i have about 2-3 gallons left, I limit my "yellow" driving to 50 miles, works everytime! Luck and enjoy. Guess I'm lucky, I can get about 275 (+/- 20) miles then Yellow comes on. :cowboy:

 

[nc-grayson]

Ive never seen over 250 miles on a tank even on the highway and running her to maybe .5 gallon left. Never seen over 19mpg either. Ive never fit anymore than 16 gal. With a 16 gal tank you used up all your reserve. Trust the gas gauge, not your scan gauge. Mine shows empty with maybe 2-3 gal left. That way I never run out.

3rd gen tank size is 18.5 gallons..correct?

would I do myself a favor to reset the SGII to a tank size of 17 gallons, or 16? I dont understand why the SGII consistently thinks I'm averaging 21+ mpg. I dont understand why they're so different between my 3rd gen and 100.

 

[MN4runnerman]

I had to walk 9 miles once after my jeep ran out of gas in the middle of the night. I hate my jeep....but also love it.

 

[GHARP57]

There is a known issue at least with the sending unit in most runners and some of the instrument clusters in the dash, only way to remedy on some is to replace both the sending unit and the instrument cluster others get by with just a sending unit replacement. The tank is 18.5

 

[jeremyc74]

Whats the deal? Do I have a busted SGII? Or am I doing something wrong? Or is it a truck issue with the fuel sender or something else?

Sorry for the rambling post. I trust the SGII in my 100, but now I'm not so sure about the one in my 3rd gen.

No lift, stock tire sizes.

The SG is calculating fuel mileage based on injector duty cycle. It's possible you have an injector(s) that are going bad, or it's possible that with this many miles it's just not that accurate. The amount of fuel the injectors are spraying can also be affected by fuel pressure, so that's something to consider as well.

Have you ever replaced injectors, or had any trouble with them?


And you're not the only one who's ran out of gas with these things. I have one of the models with the wrong fuel sender installed from the factory. It tells me it's dead empty with about 3 gallons left in the tank. On road trips I try to eat into that a little and last Thanksgiving day I ran out in the middle of nowhere in NC. A nice guy picked me up and gave me a ride to a gas station 3 miles away, but I had to walk back (he offered, but I was sharing the seat with a 120lb mastiff that seemed to have taken a liking to me and I decided the walk was better for my dignity). I figured I'd catch another ride on the way back, but it had already gotten dark by then and I ended up hoofing it the whole way. I don't push it quiet so far now.

 

[nc-grayson]

The SG is calculating fuel mileage based on injector duty cycle. It's possible you have an injector(s) that are going bad, or it's possible that with this many miles it's just not that accurate. The amount of fuel the injectors are spraying can also be affected by fuel pressure, so that's something to consider as well.

Have you ever replaced injectors, or had any trouble with them?

Nope never replaced them. I've been wondering what the SGII was using to calculate the fuel mileage, thanks for that. Im aware there are fuel sender issues and bad gas gauges for sure. In my head it made sense to me that if the fuel sender was tweaked, that would be responsible for the fuel mileage calculations to be off....but now that you say it's measured by the injectors, I'm lost.

No CELs, truck runs like a sewing machine. Wouldn't poor injectors cause some noticeable issues?


ULTIMATELY, I guess what I want to know is....how can i get my SGII to be more accurately calibrated? Is there anything?

 

[Freb_mc]

If you google it, it comes up 18.5 gal. I feel like calling bs... I've never put more than 14 gallons in mine running it down to the E. So I just assumed it was a 16 gal capacity. I check my mpg weekly and usually get 19.2. but maybe mine has an issue with sending unit...?

 

[jeremyc74]

If you google it, it comes up 18.5 gal. I feel like calling bs... I've never put more than 14 gallons in mine running it down to the E. So I just assumed it was a 16 gal capacity. I check my mpg weekly and usually get 19.2. but maybe mine has an issue with sending unit...?

What year is yours? The issue with the sending unit is only '99-'00 I think. There was a TSB for it, and the dealers would replace it under warranty if someone complained about it. It's not hard to fix. I looked into it at one point but just haven't had time. I think the parts were only about $40-50 but don't hold me to that.

It's an 18.5 gallon tank for sure. I found out the hard way.

 

[JayRolla]

If you google it, it comes up 18.5 gal. I feel like calling bs... I've never put more than 14 gallons in mine running it down to the E. So I just assumed it was a 16 gal capacity. I check my mpg weekly and usually get 19.2. but maybe mine has an issue with sending unit...?

I actually forgot its 18.5. I can only fit 14 because our gauges are way off. You have about 4.5 gal left when you hit E. If I run her under E I can sometimes get 16 gal to fit.

 

[Freb_mc]

What year is yours? The issue with the sending unit is only '99-'00 I think. There was a TSB for it, and the dealers would replace it under warranty if someone complained about it. It's not hard to fix. I looked into it at one point but just haven't had time. I think the parts were only about $40-50 but don't hold me to that.

It's an 18.5 gallon tank for sure. I found out the hard way.

Hmm, now i'm confused, maybe just overly cautious with watching my fuel gauge. Mine is a 1997 limited.

sorry for the thread jack.. didn't mean take off topic

 

[nc-grayson]

The scan gauge requires initial mpg/miles to empty calibration by the user. Then, it requires ongoing updates by the user at every fill up to make it more accurate. If you're getting bad miles to empty info it's most likely due to invalid or lack of input after refueling, not the scan gauge itself.

I have meticulously followed the first fillup, and subsequent fillup procedures to the T every fillup since the SGII purchase last year. That includes meticulous first fillup and subsequent fillups for every time I have "reset" the SG to factory settings in an effort to get the correction % down. Trust me, I've done it the right way every time.

That's why I'm questioning the slightest possibility that my SGII is a dud. It's strange to me that even AFTER resetting it every time, the fillup procedure STILL seems to recognize the previous correction percentages, as if the number it shows is the new zero %.

 

[JRZEE2000TR4LTD]

I have meticulously followed the first fillup, and subsequent fillup procedures to the T every fillup since the SGII purchase last year. That includes meticulous first fillup and subsequent fillups for every time I have "reset" the SG to factory settings in an effort to get the correction % down. Trust me, I've done it the right way every time.

That's why I'm questioning the slightest possibility that my SGII is a dud. It's strange to me that even AFTER resetting it every time, the fillup procedure STILL seems to recognize the previous correction percentages, as if the number it shows is the new zero %.

Our tanks are 18.5 gallons. There is an unusable portion of gas in the tank - roughly 2 gallons. You WILL run out of gas if you try to use that 2 gallons of gas. My son ran my truck out of gas, and it was essentially the same amounts as your reporting. I delivered 2 gallons roadside, immediately took it a mile up the road and put in 15.5 gallons. If you do the math you'll see your scangauge is pretty close

1.7 gallons at the time you run out of gas
2 gallons put in on roadside
15.5 filled

= 19.2 gallons not to far off if you ask me

 

[nc-grayson]

Our tanks are 18.5 gallons. There is an unusable portion of gas in the tank - roughly 2 gallons. You WILL run out of gas if you try to use that 2 gallons of gas. My son ran my truck out of gas, and it was essentially the same amounts as your reporting. I delivered 2 gallons roadside, immediately took it a mile up the road and put in 15.5 gallons. If you do the math you'll see your scangauge is pretty close

1.7 gallons at the time you run out of gas
2 gallons put in on roadside
15.5 filled

= 19.2 gallons not to far off if you ask me

BINGO!!! John I think you've summed up my entire fiasco much more eloquently than I could even ask or attempt to answer myself.

When you do the math that way, it makes perfect sense and things seem to add up, at least in my head they do.

The SGII is just going off of info I input. It has no clue that our fuel senders don't sit on the exact bottom of the tank and that there is roughly 1-2 gallons of unusable gas at the bottom. This thought never crossed my mind, but now that it has it makes perfect sense.

The SGII is just doing it's job....it doesn't know I basically don't have access to that last bit of remaining fuel.


That being said.....does everyone else with a SGII have to manually adjust up the volume of fuel you actually put in vs what it thinks you should, as far as I do?

TBH, I'm not even sure what the value of that fillup correction % means. i.e is a lower number better vs. a higher number etc....I assumed that making no corrections would result in the most "calibrated" unit.

But what I do know is that the 100 series virtually never requires adjustment, while the 3rd gen gets adjusted up multiple gallons each time.

John maybe you can eloquently explain what's right in front of me that I cant wrap my head around with the correction % !!!

 

[Scramble]

I've pushed it to the limit many times but never ran out. I have a 99 with the 3RZ so maybe my fuel gauge doesn't have the problem. 18.5 gallon tank, the light comes on with 3 gallons left. With 275/70R16's I was getting around 18.5 mpg & squeezing 315-325 out of a tank. Now for the past year with the 33's & lift I'm getting around 16.5 mpg & don't push it anymore. I fill it up as soon as the light comes on.

 

[trovergraywilson]

Hmm. Interesting.

Have been slowly taking care of maintenance and logging the fuel econ since I bought my 2002 back in January. Made it from Chicago to IA and partially back on one tank - all stock 5VZ-FE, 320 mi, pumped 17.5 gal in and had to Google our respective tanks' capacity. Wonder why the tank was designed with a portion of unusable fuel? I mean, in a Chevy, sure (ha), but not in our Toyotas.

 

[jeremyc74]

Our tanks are 18.5 gallons. There is an unusable portion of gas in the tank - roughly 2 gallons. You WILL run out of gas if you try to use that 2 gallons of gas. My son ran my truck out of gas, and it was essentially the same amounts as your reporting. I delivered 2 gallons roadside, immediately took it a mile up the road and put in 15.5 gallons. If you do the math you'll see your scangauge is pretty close

1.7 gallons at the time you run out of gas
2 gallons put in on roadside
15.5 filled

= 19.2 gallons not to far off if you ask me

When mine runs out, it holds 18.7 gallons. The OP said he put 18.5 gallons in his total, so it's using the whole tanks. If yours is running out before that the pickup is probably screwed up. It definitely shouldn't run out with two gallons left in there if everything is working right.

 

[jhfleet]

Hmm. Interesting.

Have been slowly taking care of maintenance and logging the fuel econ since I bought my 2002 back in January. Made it from Chicago to IA and partially back on one tank - all stock 5VZ-FE, 320 mi, pumped 17.5 gal in and had to Google our respective tanks' capacity. Wonder why the tank was designed with a portion of unusable fuel? I mean, in a Chevy, sure (ha), but not in our Toyotas.

One reason for having unusable fuel is to protect the in-tank fuel pump from overheating. If every last drop can be used there'll be inadequate fuel for cooling the pump during the last 30 or so miles.

 

[JRZEE2000TR4LTD]

BINGO!!! John I think you've summed up my entire fiasco much more eloquently than I could even ask or attempt to answer myself.

When you do the math that way, it makes perfect sense and things seem to add up, at least in my head they do.

The SGII is just going off of info I input. It has no clue that our fuel senders don't sit on the exact bottom of the tank and that there is roughly 1-2 gallons of unusable gas at the bottom. This thought never crossed my mind, but now that it has it makes perfect sense.

The SGII is just doing it's job....it doesn't know I basically don't have access to that last bit of remaining fuel.


That being said.....does everyone else with a SGII have to manually adjust up the volume of fuel you actually put in vs what it thinks you should, as far as I do?

TBH, I'm not even sure what the value of that fillup correction % means. i.e is a lower number better vs. a higher number etc....I assumed that making no corrections would result in the most "calibrated" unit.

But what I do know is that the 100 series virtually never requires adjustment, while the 3rd gen gets adjusted up multiple gallons each time.

John maybe you can eloquently explain what's right in front of me that I cant wrap my head around with the correction % !!!

I just got the Scangauge a month ago but I believe that correction % goes negative if the actual gallons you put in is more than the amount it thinks is in the tank. Maybe it's the opposite. I don't know exactly as I haven't done a third fillup yet. It "should" be fairly close though after a few fillups. Seems like yours is. Just like a lot of people on here, I fillup soon after the yellow low fuel light comes on and I almost religiously put around 14-15 gallons in it.

I believe the reason for the 2 gallon "reserve" is so you don't suck the bottom of the tank and pull that sediment in although when I dropped my tank to find a mysterious noise coming from the tank (I posted about what I found about 8 months ago) the tank was spotless. It's probably not this at all and is just a slight design flaw but it is easily compensated for by just filling up soon after the light comes on.