If you can eliminate that feed to the battery and use all the output for momentum, you reduce the conversion losses to and from the battery. By doing P&G yourself, you're taking control and doing better than the "pretty good" internal management.
Despite thinking about conversion losses, I failed to come to that conclusion myself. Now I understand how and why.
so anyway, back to the topic... having such a button would make it VERY easy to get 100mpg instead of having to find that spot with the gas pedal. It's not that hard to find at speeds below 41mph, but above that it's very difficult. Being able to engage it by just pushing a button would mean anyone could hypermile their Prius to astronomical mpgs.
Lazy, and so many simply can't handle the extra technique. A customer of mine traded in his Cadillac for a Prius probably about 6 months ago, and his wife traded hers for a Hyundai Genesis. We were talking about cars the other day while I worked on his computer, and here's what he had to say.
The Prius: The lots of lights and gauges concern him. He doesn't know what they're all about and can't keep up with them while driving. They are a distraction while he's trying to drive.
The Genesis: It has a bunch of controls in the front of the armrest, between the console cup-holder and the armrest. He can't operate them without looking at them, and is deathly afraid of his coffee spilling on them.
This guy is no simpleton. He's been running a successful business for decades, and wrote very complex business systems in an unpopular and probably not so well documented macro language. That was some years ago and he's old and inflexible now, but he should be able to handle car gauges and controls. I believe he represents a major portion, if not the majority, of the consumers out there.
I've come to the conclusion that the vast majority don't actually drive their vehicles. They just point them in the direction they want to go and mash the accelerator. It's the only explanation I can think of for some of the stupid traffic moves I see every week, as well as apathy over improving fuel efficiency. If there's any effort involved -- or they even simply have to think about it -- they're not interested.
That said, I understand the concept of something being merely a tool to get a job done. Not everyone who uses a computer or drives a car is going to be an enthusiast; they just need to check their email or get where they need to be. And I suppose as long as they do so safely, anything beyond that is gravy.
And, sadly, uncommon.
who often pines for the fuel efficiency even he, as a moderate and often distracted hypermiler, could achieve with a Prius.
I think a major benefit would be for Toyota to remove the 41mph limit. Above that, the engine runs, no matter what the conditions. Below that you can get the engine-off glide. They have test models for the upcoming plug-in, and they allow engine off up to 60 (61? 63?) mph. It's not a mechanical limitation, it's a software one.
They have test models for the upcoming plug-in, and they allow engine off up to 60 (61? 63?) mph. It's not a mechanical limitation, it's a software one.
Did they make any hardware changes in the test models? I'm not really up on Prius specifics, but I remember reading that something would be spinning too rapidly above the cutover speed if they didn't fire up the engine (something in the Hybrid Synergy drive or one of the MGs, I think it was).
That might have just been someone theorizing as to why the limit was there, though; I don't remember. Does anyone know for sure? It would be very cool to run engine-off at higher speeds if the conditions were right.
I believe the 61 mph limit is the actual physical limit for the MG motor. I believe it's spinning 10,000 rpm at that point. I believe this test model had a larger battery pack for plug-in range, and tweaked software. That's all the changes I'm aware of. Wayne Gerdes reported from 10 minutes of driving, and that's my only source.