Normally I fill up when I have an indicated 1/4 to 1/8 of a tank left. There may not be a true "reserve" compartment on these bike but they do have a "live bottom". When the display reads empty on my 2022 RT there is still over a gallon (US) of fuel left. We ride out in the boonies and when route planning I need to know how far I can go on a tank. Right now that appears to be between 162 and 192 miles based on terrain and speed. So when the display says "Low Fuel" it means we have a bit over a gallon of fuel left or approximately 35 miles.
That amount of fuel left in the tank after the gauge reaches 'Empty' is by design - it's intended to keep you, the operator, from running the remaining gas level too low for it to do its job properly! IIRC there's even a warning in the glovebox manual about
NOT running it much past that level where you tell us you normally re-fill! :lecturef_smilie:
The reason for that thing you're calling a "Live bottom" is not only so that you
don't run the gas tank dry, but also so that you
ALWAYS have enough gas left in the tank for all the reasons I stated earlier - you
REALLY NEED to keep sufficient fuel in the bottom of the tank to keep the fuel pump fully immersed & therefore properly lubricated
AND for there to always be sufficient fuel around it to disperse the heat generated by its operation. Funnily enough, it turns out that on our Spyders, the amount of fuel required to do that properly pretty much all the time is getting up there fairly close to about a gallon!! :shocked:
So yeah, you have gas left in your tank once the gauge reaches 'Empty'; and yeah, if you're not concerned about damaging expensive & difficult to repair things in your Spyder that are crucial to its running well, you can use that gas to go a little bit further.... But once you run the gas level down that low in the tank, all the microscopic crud & water type contaminants that
DO end up in your tank become more concentrated and some
WILL start getting sucked in past the filter &/or start clogging the filter up, further restricting the necessary fuel flow; the increasingly insufficient level of gas remaining in the tank
WILL allow those important bits to overheat/fail to be lubricated properly simply because the gas level remaining isn't sufficient to disperse all the heat, further compounded by the slightly but increasingly restricted flow rates; and you
WILL be causing damage to those expensive &/or difficult to repair/replace components that work to very fine tolerances - so even if you do think you got away with it, the damage caused is
inevitable if you run the fuel level that low; it's
initially microscopic; it's
irreversible; and once started, it is
cumulative and it gradually continues to get worse over time as the pump continues to rotate thru normal operating and gradually/over time rips itself apart, getting less & less efficient as the damage
you've caused grows & grows until it eventually fails! :banghead:
Just Sayin - Again!

:bdh: