Nw 2016 LC -19 gallon tank? Thought it was 24.6 gallons?>

[serpico1]

Hi all,

I just got my new 16 LC and love it. I love this forum and have some other questions so of you LC experts can help me with but very quickly.

I was on empty, literally fumes and I stopped to fill up and it was exactly 19 gallons. Doesn't the LC have a 24.6 gallon tank?

Happy to be an LC owner and thanks again.
Thank you,

 

[studawg]

When the low fuel light comes on, there is still about 5 gallons in the tank.

 

[serpico1]

Thanks but the range on the onboard computer said I had 12 miles left?
Normal?

 

[kevinfoutch]

Yep, overly conservative on Toyota's part with regard to miles remaining I suppose. Other forums discuss this, and I also use the UltraGauge Blue OBDII which confirms this. That being said, I have never tapped into that "5 gallon reserve" to see what the on-board computer's miles remaining would say, e.g. stuck at zero or does it display negative miles to go?

 

[serpico1]

got it, thanks and understood now. I appreciate the response.

 

[linuxgod]

Correct, the remaining distance doesn't go negative. "Cruising range" is the number of miles until the low fuel light comes on. That's supposed to come on when you have about 5 gallons left. I've found I have closer to 6 left when that happens (and the needle is resting on the Empty line too). It's disconcerting to see the needle touch the line and not have the light come on yet, for sure.

 

[MScruiser]

I have driven at least 50 miles past the "Cruising Range 0" and have yet to actually run out of gas. I am very interested to know EXACTLY how much mileage I have after "0" given a certain RPM range.

 

[linuxgod]

I have driven at least 50 miles past the "Cruising Range 0" and have yet to actually run out of gas. I am very interested to know EXACTLY how much mileage I have after "0" given a certain RPM range.

I just got the TIS Techstream dongle so I'm curious to see if there's a way to adjust the cruising range. I assume not but will give it a shot when I have a chance.

 

[bigbassinbob]

I couldn't believe how ridiculous this decision was on toyotas part when I bought my LC a few months ago. Actually made an appt to take the truck into the dealer because I thought my gas light was broken since it wasn't coming on even though it showed I had less than 5 miles "to empty." I still can't for the life of me figure out why you would make a car that tells you that you have no gas left even though there are 5 gallons left in the tank. It effectively makes the fuel capacity 19 gallons since there is no way to tell how much fuel is left after that. This still drives me crazy.

 

[kevinfoutch]

I think @linuxgod may have alluded to this above, but perhaps the intent was to be the length of time before you need to look for a gas station, not the length of time before you are stranded on the side of the road. Regardless of the intent, at least the behavior is consistent and it would be interesting to learn if this parameter is configurable.

 

[Markuson]

Thanks but the range on the onboard computer said I had 12 miles left?
Normal?

Completely normal.

My range says zero when the light comes on...even though I've got about 4.5 gallons left.
Toyota plays it super safely with their range estimates--likely because this thing drinks gasoline like a drunk drinks beer...

 

[Ivan Nanola]

Got one just over a week ago. Tank looked close to empty but no warning light. I had no idea how big the tank was. Filled it with just over 19 gallons for $48. Wife and I were cracking up because I filled up this beast for under $50.

 

[rcpalmer78]

I usually hit the trip reset button on the odometer when I get down to zero on my distance remaining. I feel good going 30-40 miles in town before I really need to plan on getting gas. It's kind of a hassle but much better refueling very 20 gallons. I used to feel like I was living on the edge like this - kind of like the episode of Seinfeld where Kramer and the salesman test drive the Saab until it runs out gas, just to see how far they can make it - but now it's just part of my routine. My wife does the same in her LX and the Sequoia before that.

 

[gaijin]

Perhaps Toyota is so conservative because the fuel pump is inside the gas tank and it would be very bad to run the pump dry - and very expensive to replace if it burned out.

 

[linuxgod]

Perhaps Toyota is so conservative because the fuel pump is inside the gas tank and it would be very bad to run the pump dry - and very expensive to replace if it burned out.

Running the tank dry can cause the fuel pump to burn out since gasoline helps cool and lubricate the pump. But almost every manufacturer has the fuel pump inside the tank now.

I don't mind the gas light coming on with 5 gallons left, or the MID showing the cruising range tied to that. What irritates me is the fuel gauge calibration - the needle rests on the empty line when there's almost 25% of the tank left (6 gallons remaining in mine). It wouldn't bother me if it showed 1/8th of a tank and reserved the last 1/8th for the area below the line.

If Toyota really doesn't want you to run the tank dry because of fuel pump or injector damage then they should have fitted the vehicle with a 30 gallon tank. What actually happens is that people get overconfident in their ability to run past empty because the gauge is so far miscalibrated that at some point the oversized reserve actually increases the likelihood of running out of fuel (for instance when you "know" there's 5 gallons left and can therefore go 85 miles (5 gal x 17mpg) but you're driving into a headwind or your O2 sensor isn't reading right and you run out of fuel at 60 miles (5 gal x 12mpg) because once you hit that empty line you're now driving without a gauge! Ok rant over).

Anyone have access to the FSM? I'm curious what values the fuel sending unit provides to the ECU or gauge and if you could hypothetically splice in a resistor to "recalibrate" the gauge by fooling the computer into thinking there's more fuel in the tank than there is.

 

[T4Runner]

It's like setting your watch ten min fast so you won't be late, but since you know it's fast, you end up late anyway. What's the point?

 

[Markuson]

It's like setting your watch ten min fast so you won't be late, but since you know it's fast, you end up late anyway. What's the point?

So true. KNOWING it's set ahead ruins it.
On the other hand...maybe that means we all did him a disservice by telling him he really had 4-5 gallons left!

 

[linuxgod]

I'm curious what values the fuel sending unit provides to the ECU or gauge and if you could hypothetically splice in a resistor to "recalibrate" the gauge by fooling the computer into thinking there's more fuel in the tank than there is.

Replying to myself for posterity (and because perhaps someone will want to try and solder up a solution to this).

According to the FSM (GSIC - Global Service Information Center), the fuel gauge is determined by measuring the resistance between pins 2 and 3 on the fuel sender gauge assembly. There is low resistance (12 to 18 Ω) when full and high resistance (405 to 415 Ω) when empty.

Condition Specified Condition
Float level is F (upper) 12 to 18 Ω
Float level is E (lower) 405 to 415 Ω

So a resistor inline won't work because more resistance will cause the gauge to read empty sooner. Assuming linear resistance corresponds to a linear decrease in fuel in the tank, in order to "correct" the sending unit, you'd actually need to split the output from pin 2 and run a parallel wire back to pin 3 which skips the sending unit, then add a 2000 Ω resistor (or thereabouts, depending on how much correction you want).

There's a decent calculator available to help with the math of Ohm's law at Parallel and Series Resistor Calculator. 2000Ω is a 17% correction. 5000Ω is about 8%.

 

[BTUMAN]

Like others have shared- see light on, reset one of the trip odometers, know you have at least 50 miles.

 

[chilibit]

It is fine just like it is IMHO. Given that we top off out in the boonies you will find all manner of crud in the bottom of the tank. "You got my back Toyota? We got your back."