I never advocate for anyone taking the risk of running out of gas. It can be dangerous. But in a suburban setting? Or in an environment where gas stations are plentiful, I think you can safely run down to 1 pip. And I think that perhaps part of the problem is the OP has been filling up, relatively early. I'd be curious what the range would be on a more empty tank. I'd be curious as to the "actual" calculated by hand MPG. But you are correct. You can fill up at really any point, and if you are paying attention to how much you are adding, and how far you have gone, your calculations should be accurate. Just for precision, If it was me, I'd try to refill as consistently a couple of times in a row. So whatever point of refill you would choose, I would refill as close as possible to that same point, 2-3 or more times. So you've changed my mind. You could refill at any point...safely....but I would just be as consistent as possible for a few fill ups.
Here in Queensland, "... is sounding an alarm or showing flashing red or blue lights, you must move out its path as soon as you can do so safely ... The law allows you to drive onto the wrong side of the road or drive through a red traffic light to get out of the way of an emergency vehicle if it is safe to do so." BUT - that isn't the case everywhere - I saw where our neighbours, NZ, it's quite the opposite.
Yeah...I kind of dropped the ball on that approach. But really? I'd say just keep driving. Fill with the RIGHT gasoline. And hand calculate actual MPG at the pump for a few fill ups. That's really relatively simple.
I have changed my stance on the approach. I would like to see the OP consistently fill up at about the same point, for a few tanks in a row, and calculate the MPG by hand. BUT... Yeah, no need to take the risk of running out of gas. Fill up before it get's too low.
There was another thread conversing about conniving CATS catnapping on cars. (I'm actually quite seriously allergic to them.)
Oh dear. User Chime, I hope you are still looking at updates here. I need your attention. I normally only hang out on the main forum when I occasionally check in and have missed this thread. Caught up a bit on your posts and am deeply alarmed. There is no need for any further investigation or data gathering to prove something is wrong. There is no doubt something is wrong. The behavior you described is NOT NORMAL! I don't care what kind of driving habit you have, but no amount of messing around should lead to that. The gas gauge on My 2018 Prius Two post-fill will move off of FULL after at least a hundred miles of driving. Any car I have driven (Prius or not) has always exhibited the same behavior (10s of miles at the minimum). I read that you scheduled for window tinting. If I were you, I'd cancel that for now until you figure out the issue. If you bought it new, and the issue could not be figured out (by the service department), is it possible to buy another car from the dealer? Best of luck and please keep us posted of any new development. BTW, are you really getting your window tinted at your dealership? I've gotten quotes from many places because I also plan to tint, but the quote from any dealership is far far more than those from window tinting businesses. Curious what your quote is if you don't mind disclosing (I'm in the Bay Area too).
It's obviously impossible to burn through that much fuel in a Prius. What remains is a fuel leak (the fuel is going in, but it's pouring out onto the road), incorrect fuel gauge (e.g. the gauge's empty position is really 80% of a tank), or incorrect filling (the fuel pump is turning off, suggesting the tank is full, but it's not). The latter can be eliminated by looking at the cost/volume of the fuel that went in on the pump. The other two should be looked at by a the dealership.
Her first fill was irrelevant. She's gone off to check her figures and record them carefully over a couple of weeks - I'm sure she'll come to the conclusion that there is no problem. Her dashboard computer readings indicate all is normal. Expect her to report back in a couple of weeks.
To be honest - I never watch to see if it moves. I've got better things to look at. I commented about petrol gauges in the past - you could only believe them if you were stopped on level ground - some would move wildly with changes in incline or cornering. Maybe PRIUS does that?
There is no way this could be normal after a fill up. Based on the posts she's provided, she does not sound like a troll. That's why I'm very concerned for her. I know I'd be very stressed out if my brand new car has a hard to diagnose problem.
Until she comes back with some definitive figures - $$ plus ODO readings, it's conjecture. She has to eliminate the first fill, as it has no relevance - it was just getting it to "FULL". And, if her first petrol pump was faulty and cut off early with that first fill (which is quite possible, I've had a few here which did that) which only filled it to 7/8, the gauge would show full, but the next fill would be double what you'd expect. Wait till she comes back with accurate figures.