There are three arrangements: 1. Input Split (Prius) 2. Output Split (Volt) 3. Compound Split (GM 2-mode) There is an SAE paper from 2005 that explains the tradeoffs available for free at the following link: https://confluence.engin.umich.edu/download/attachments/1605717/HybridVehiclessession5-2.pdf
I also read somewhere that the volt could have been made more fuel efficient in CS mode if they had further decoupled the engine from the accelerator pedal. In other words if they chose to run the engine at steady state max efficiency more of the time, but some of the designers felt the engine should rev in response to the pedal more to give feedback to driver. It could also theoretically reduce wear and tear on the battery.
Yes, that is quite true. Running at most efficient mode gets rid of most of the advantage of cooled egr and late intake valve closing. You do need to add losses in charging and discharging the battery. The prius engine still is likely more efficient, but the gap closes. Drivers do want some engine feedback, but maybe an eco button should turn that off to make it most efficient.
Page 13? OMG what have I started? It was a serious question and has now turned into a monster. Will I ever learn?
Mine doesn't, so does not the PiP I tested last year. I thought the production mode had that... Where have I read that? :noidea:
Monster? Naa.... BTW Opel Ampera here in Pt : 44500euros Chevrolet Volt here in Pt: 41950euros I'm hoping PiP can be "a bit" under those prices...
Thanks for the link.. interesting reading, though from the definitions in that paper I believe the Volt can be an output split (when in 1 or 2 mode EV) or a a compound split (there are gears between engine and rest and gears on after the planetary carrier). Its not as complex as the compound split in the two-mode, but still seems to be compound. But that paper also suggests the compound split is the most efficient, which is not what USB claimed, I wanted him to show something that backs up the statement that input-split is more efficient.
We've got optimizers debating with those who live by the 90/10 rule. It's a recipe for endless posting. The thread will go on and on, since ultimately the goal is the same... but approach differs significantly. The economic realities of business requires what one group calls "balance" and the other calls "compromise". The nature online posting format makes those debates difficult to follow. Detail is easily lost or forgotten. That's why, in the end, it always comes down to sales. Regardless of all the circumstances at play, those results must be accounted for. The clock is ticking for Volt. Things haven't went as planned. Some type of revision must emerge. .
It comes down to sales for you b/c you know the PiP will win that battle. It costs way less it is going to sell more. Toyota has brand recognition in the Prius it will sell more. I don't think anyone believes the volt will outsell the PiP. I would assume the PiP would sell orders of magnitude more. Just as the Leaf sold way more than Tesla's offering.
The following image does a good job of explaining Its from a slide deck from Argonne Labs http://www1.eere.energy.gov/vehicle...w_2010/veh_sys_sim/vss010_rousseau_2010_o.pdf
Isn't the point of sales to make an automaker profit, some of which to reinvest with? Dependency on tax-credit money and a $8.63 loss on each of the 500 million shares of GM stock our government still owns doesn't exactly leave Volt in good standing. How will GM fund the development of the second generation model of Volt? .
Direct loss. But they get much higher dividends than most shareholders: from the company, from the company's employees, from the company's suppliers, from the company's suppliers' employees...
huh gm had a profit of $4.43/share last year and a forward PE of 6. Auto companies pay for R&D through continuing operations not issuing new stock. Both Toyota and GM lost market value for stock last year, but made profits and have funds to develop new cars. Both the prius phv and volt will lose money in 2012, unless you do fake accounting, and both companies have money to develop the next generation. The Prius is profitable, but makes much lower profits in both margin or absolute value compared to say the F series truck. That does not mean Toyota should cut this car and concentrate on trucks.
GM profits in 2011 were something like 6Billion, see Detroit automakers are (finally!) making profits - Jan. 5, 2012 They are investing in the future.. A EREV future. GM can always fund the development of the second generation with its profits (e.g. from sales of the Cruze.. The Volt "halo" and price help sell the Cruze Eco which has a much higher margin. GM does not have to sell Volts for Volts to help them to sell cars. If they lost 1K per car and sold 35,000 of them, it would cost less than the average superbowl commercial. And hey, satisfied Volt owners like me are out there defending them..
LOL GM accountant: tell me how much you want 'profits' to be, and I'll tell you much of your expenses have to be hidden or paid with government bailout money.
One of the beautiful thing about the Volt is the owner gets a choice of how green they want to drive -- lots of volt owners are driving on on renewable energy. Maybe with today's average electricity its not, but if you care enough to buy a "green" car, why not go a bit farther and drive mostly on renewable electricity. You cannot do that on in a regular hybrid. At least the PHV is a plug-in so you can be a little greener. In terms of efficiency, of the 396 people on voltstats.net more than 350 have an average MPGe above 52mpge.. that is more efficient than even a liftback. And 68% of them have an MPGe better than the epa's "60MPGe". So while I'm doing well, I'm not all that unique or an exception.
You are however assuming that voltstats.net is a representative sample. I really want to know why you continue to quote idiotic MPG(e) numbers when you have no idea of the source fuels used for electric miles.
Since I'm not computing statistics I don't have to assume its a representative sample. I was just showing that I'm not an exception so even if its a biased sample, its sufficient. MPG(e) is the measure of tank-to-wheels efficiency. Its not idiotic if I'm arguing about the beauty of getting the electricity from renewable sources. You have no idea, or even a choice on the source of your gas. Does that make MPG a useless number?
Imagine for a moment that only the top decile of Volt owners in fuel economy bother to post their results. Then you are in fact the exception, if the inference is your results within the total group. Since you do not know how biased the group is, you really cannot say one way or another how exceptional your results are. I suggest you not obscure the fact that you fuel up your car with wind with national MPG(e) statistics that imply nothing of the sort. No, because my neighbor uses the same sources. If my neighbor only used the "tar sands" gas stations, and I only used "Venezuela" stations, I would dispute my neighbors use of MPG(e) as meaningful.