No, the auto-shut off does work. I think there is a sensor in the gas pump to recognize the tank is full. I squeeze with my hand until the pump automatically stops.
So, if that is a new thing on 2020 PRIME not present on 2017 PRIME, it could be a culprit for what's happening on OP. I will report when I fill my tank. Heck, the gas price just tanked $.10 over night, I may just stop on my way home to see what happens. I can put at least a quarter of tank filled.
Yep. I didn’t notice the new style gas fill opening on my 2020 until you posted the shot of it (they also now enclosed the flap lock... nice!). Most of the gas stations near me have removed the auto lock feature on the nozzles so I haven’t noticed any issues, but I think you’re on the right track that the flow is somewhat restricted now, and if the flow rate is too high, the pump senses enough back pressure to shut off. if I recall correctly, the pumps that I have used with the locking feature had several different steps to allow for a different flow rate. The OP might simply try to set the lock at a lower flow rate. Yes/no?
FYI, IIRC the fuel door lock protector was added sometime during late 2018 model or 2019 model. See the comment #5 in this thread: Problems refueling | PriusChat We have had discussion on that topic not being able to refuel some models of PRIME when that lock switch was inadvertently activated. I will report on the ability to use the fuel pump trigger lock after I do my first refueling on my new 2020 PRIME. Yes, the low flow rate trigger may be the solution.
Have you tried at different stations and pumps? Some pumps have more sensitive shut off sensors. Of course, it is possible that the shape of the filler tube results with more splashback and triggering that sensor when releasing the pump with lock in place. Could the Prime be getting the Rav4h's filler system? Is Toyota's solution to that problem to just make all the cars hard to fill. It may be a design to reduce evaporative emissions while filling.
I've only had to fill up once (and it was only half full, but I had rewards points that were expiring and which lowered the price to $0.74/gallon!), but I did not have this problem. The nozzle stayed in and locked as they have for all my previous cars.
@Salamander_King For the record, I checked my 2018 built Nov 2018, it doesn’t have the plastic piece nor the lock protector.
Thanks. The lock protector must be the 2019 model and later. The white piece in the fuel neck might be a new thing in 2020, but I don't know. I have a feeling @Trollbait might be correct on guessing something new similar to Rav4 fuel system. My guess is that some gas stations with a nozzle wrapped around spring as shown in the picture in my comment #11, the nozzle does not insert all the way in because of the white plastic part in the fuel neck opening. That may be the cause of the OP's problem.
I haven't had a single problem with the pump nozzle falling out in my 2017. Here in Cali, we have those vapor recovery type nozzles, but I would think they would be more susceptible to that. Make sure you insert the nozzle in as far as you can. With the vapor recovery nozzles, that means compressing the outer hose, which is accordion shaped at the nozzle end.
See the photo in my comment #12 Pumping gas | PriusChat I haven't yet refueled my 2020 PRIME to test my theory, but that white piece of plastic which is new in 2020 model is restricting the fuel neck opening causing the problem OP described.
@bisco is correct, my Prime hasn’t had a problem in the 9 times I filled it up, but I did have it kick off a little prematurely in the summer and had to fill it kind of slow. My PiP was a little tricky at times when it came to fast fuel flow but I think I could blame that on the gas pump, but nothing was as problematic as my Gen 2 Prius. Frustration to the max. Wife’s NXh, no problems, although I’ve learned to stop it after the first click. iPad ? Pro
Weird. This reminds me of the bladder issues from the ol' gen 2 days.. PHEV's have pressurized fuel tanks to help minimize fuel oxidation during long term storage so I'm thinking your issue has something to do with this. No codes? Maybe try activating the fuel button a time or two before pumping. Maybe waiting a bit for pressure to equalize (get that coffee first).
All modern cars have pressurized fuel systems and components to reduce evap emissions. Some even have systems to capture fumes while filling. This might be Toyota's equivalent to Ford's capless system for doing that.
Maybe this is not universally true, but in these parts, a green pump handle always means diesel. Black used for gasoline.
Yes, I think so. Or at least for using unleaded gas, on both 2017 and 2020 PRIME owners manuals, there is a statement to that effect. What I don't remember is what the 2017 PRIME fuel opening looked like. Can you take a photo of your 2017 PRIME fuel tank opening with the fuel cap removed, so we can compare the difference?
I think that started in order to keep leaded and unleaded gas cars from using the wrong fuel; unleaded had narrower. Some places still use leaded gas. I never checked the diesel nozzle at the gas station, but have seen video of a gas car that put diesel in by mistake from the UK. Note to those that travel the black nozzle is gas and green is diesel used in the US is reversed in the UK. Now truck diesel pumps won't fit a car, but that is because those pump at a faster rate that result in overflow and back up if used in a car.
Just to report after my first gas fill-up for the 2020 PRIME LE, I had no problem using the gas pump trigger lock mechanism and auto-stop for hands-free filling. I am not sure why the OP is having a problem with this feature. The operation was identical to what I used to do with 2017 PRIME Premium. Thus my theory of a different filler neckpiece causing the restriction of the gas nozzle into the 2020 model is not supported.