My 2020 Prius excellent report!

200k? road warrior, well done!

 

How do you get that mpg? Mine just around 47 on winter and 55 on summer. Is it a plug in?

 

Billy have you tried using a 2x4 or 4x4 under the rear tire? I do this for my f150 and did it with my tdi. It helps to not get air trapped in the tank. I am not sure how the prius tank is but there has to be some sort of air trapped in it.

 

Ok I'll bite: you roll a rear wheel up onto a wood block? When gassing up? This does something?

I'm not trying to be derisive, just wondering if I'm understanding, and what you're trying to accomplish.

 

Driving up on the wood allows the filler tube to be higher. This in turn should trap less air in the tank and allow quicker and more complete fills instead of filling and waiting for the level to go down the topping off several times.

Filling at a pump that allows the passenger wheels to be lower than the drivers wheels has the same effect.

 

It's possible that Wayne Gerdes is driving a vehicle that doesn't have onboard-refueling vapor recovery (ORVR), or that he has removed the ORVR components, or that he only needs the vehicle for the duration of a publicized hypermiling stunt and doesn't have to care what happens to it beyond that.

One of our most instructive PriusChat threads on the topping-off business is one that eventually ended with the member being "confident to say the problem is resolved" after replacing the affected ORVR parts, but never dropping the topping-off habit. Same member started another thread about the same issue eight months later.

All the great hypermiling techniques for improving your economy will work just as well if you buy fuel at half a tank and stop when the nozzle shuts off. Over time, you buy the same amount of fuel for the same number of miles. There's no particular need to push how full or how empty you can run the tank, outside of doing some kind of distance-on-a-single-tank stunt.

 

"Topping off", or "stuffing" the fuel tank will result in shortening the life of the purge solenoid. You'll eventually get a CEL leading to an expensive repair.

 

There are a bunch of components in the ORVR system; the purge solenoid is just one of them.



A common outcome of habitual topping-off is liquid fuel ends up in vapor-carrying passages such as the ones seen here between the tank and the filler neck, the canister or the cutoff valve.

Then you don't necessarily get a check-engine light, but you will be annoyed when the tank only accepts 2 gallons at a fillup and then belches it out on your shoes, and the repair is kind of pricey.

That illustration shows a bladder tank, which was only used in Gen 1 and Gen 2 in the US. The ORVR system for Gen 3 is pretty similar, only without the bladder. I don't have a Gen 4 ORVR diagram handy.

 

Wow thanks for sharing Billy. That is very impressive MPG indeed. Is the ride much harsher with the high 51 PSI in the tires? Have you had to replace any wheel bearings?

 

Thanks for sharing Billy the MPG report. That is truely amazing MPG. Does the high tire PSI and ride harsh translate to wheel bearings and shocks wearing out prematurely?

 

Billy what brand tires are you running?

 

Wayne's trying to eliminate pumping variables, doing mpg testing. As others have said, it's not good practice, for various reasons.

Maybe...