Fuel Gauge Accuracy

[nihilist]

I took on some risk and kept riding long after the fuel warning came on. It does indeed still have 1/3 of a tank left when the warning starts. I had it come on at 225km and rode until 330km before refueling, at which point I filled up with 15 liters of gas. That's bang on what I should use, considering my average was 4.6L/100km. So, presumably I would have run out of gas at about 391km.

[steve]

@nihilist, are you getting to reserve around that distance consistently? If so I'd suggest you have the dealer check that out for you, that is not right.
 
I'd estimate it ought to have gone onto reserve around the 335km mark [15.4 (tank to reserve) / 4.6 * 100], furthermore for a 15 litre fill you should never have seen the reserve warning come on at all as that should only happen at around 15.4l, let alone riding nearly 100kms on it.
 
Since merging the posts I see you have already have done the calculations. Doesn't sound like your fuel sender is calibrated properly.
 
 
 
 

[steve]

I've merged the topic Fuel Gauge into this.
 

[basstodave]

When I first bought my FJ and before I found this forum I thought my fuel sender was broken. I took it to the dealer. But at nearly the same time I read this thread, realized my mistake, tried to stop them, but the dealer went ahead and under warranty replaced the sending unit I believe.
 

[nihilist]

@nihilist, are you getting to reserve around that distance consistently? If so I'd suggest you have the dealer check that out for you, that is not right.  
I'd estimate it ought to have gone onto reserve around the 335km mark [15.4 (tank to reserve) / 4.6 * 100], furthermore for a 15 litre fill you should never have seen the reserve warning come on at all as that should only happen at around 15.4l, let alone riding nearly 100kms on it.
 
Since merging the posts I see you have already have done the calculations. Doesn't sound like your fuel sender is calibrated properly.
 
 
 

I was getting almost exactly the same behaviour every tank - warning at 225km and then getting in only 12-13L of gas.
 
I think my dealer recalibrated the fuel sensor when it went in for service.  My last tank, during which I had my first service, went over 300km (maybe 310-320km?) before getting the fuel light, but the warning had come on right when I pulled into the parking lot so I thought maybe they had put a couple liters in thinking it might be almost dry.  However, this tank is over 150km and is still showing all the bars so my guess is they did recalibrate.  

[2and3cylinders]

My new in July 2016 Red 2015 FJ-09 gas gauge was fairly accurate and ran down normally until recently (at about 5,300 miles) when it started sticking on full until about 105 miles then suddenly dropping to half full where it should be approximately. This has occurred over the last 4 or so fill ups except for one when I filled up and the gauge was stuck at about half way then suddenly went to full and then did the usual stick until 105 miles thing. Weird.
 
 
 

 

 

[root]

My new in July 2016 Red 2015 FJ-09 gas gauge was fairly accurate and ran down normally until recently (at about 5,300 miles) when it started sticking on full until about 105 miles then suddenly dropping to half full where it should be approximately. This has occurred over the last 4 or so fill ups except for one when I filled up and the gauge was stuck at about half way then suddenly went to full and then did the usual stick until 105 miles thing. Weird. 
 
 

 

Showing "full" until the tank is half empty is expected and the way the fuel gauge was designed by Yamaha. Please read through the previous pages on this thread for more info.

[2and3cylinders]

I did read all the prior posts but my FJs gas gauge DID NOT act this way until it had over 5,000 miles. Could this change have been a ramification of an ethonol soaked fuel level sensor after extended submersion?

[2and3cylinders]

I did read all the prior posts but my FJs gas gauge DID NOT act this way until it had over 5,000 miles. Could this change have been a ramification of an ethonol soaked fuel level sensor after extended submersion?

[pcarnut]

I'll add my .02. First, I'm a big Yamaha fan, but I'm disappointed Yamaha gave us such a silly fuel gauge that requires all this playing with numbers while riding. Having a fuel gauge that goes from full to half-full in one jump is stupid as far as I'm concerned. Okay, off my soap box now.
 
After bunches of checking, what I've found is that when you have one bar left, with in a few ounces, you have one gallon left, it's that simple, ride accordingly.

[martyl]

Doing the math is the best way to estimate fuel. That's the old school way. Just remember to reset the trip meter at fill up. The only variable is good fuel or crappy fuel.

[rustyshackles]

My 2015 drops to 1/2 tank at around 90 miles unless it's been all highway riding (110 max in that case). The first small segment disappears quickly, then the rest seem to hang on longer.
 
On my last tank (2/3 highway, 1/3 twisties) the last segment started blinking at 152. At 162 I filled up and put .80 gallons in.
 
When I've done the math MPG were 38+/- for commuting, 43+/- highway. I'm at 12,500 miles.

[martyl]

My 2015 drops to 1/2 tank between 90 and 100 miles unless it's all highway miles (110 max in that case). The first small segment disappears quickly, then the rest seem to hang on longer. 
On my last tank (2/3 highway, 1/3 twisties) the last segment started blinking at 152. At 162 I filled up and put .80 gallons in.
 
When I've done the math MPG were 38+/- for commuting, 43+/- highway. I'm at 12,500 miles.

 
 
That sounds about how my FJ09 is doing. Averaging around 42 mpg.