Prius Killer - Hybrid Honda Fit?

<div class='quotetop'>QUOTE(usbseawolf2000 @ May 16 2006, 09:36 PM) [snapback]256594[/snapback]</div>

Honda people think I am a Toyota fanatic. Toyota people think I am Honda brainwashed. Would you guys make up my mind already ?!!?

I didn't clarify -- In saying 'fit' for small or large cars, I was not speaking from an engineering perspective, but in regards to cost. And if we get a $17K Fit hybrid in 2007, I'll be right -- at least for a while. But hopefully not for long.

I want results !! Loyalty is for stockholders, middle management, and fanatics. A person who chooses HSD over a competing tech while considering it an inferior choice based on some future promise, is acting silly, and just might have delayed the promise.

 

I think John has a point about the long-term solution. The HSD can already be made a plugin (for those that have the means to do the conversion), greatly reducing or eliminating buying gas for some individuals. Honda's IMA can't do that now or for the forseable future. Not to mention being able to be used in a wider variety of engine sizes.

Toyota's HSD design seems to have more further growth because it can lower the dependence on gas much more than the IMA, because all of the foundation is there in the HSD to make it a functional EV vehicle for everday use. Now, maybe this will still take another 4-5 years to happen on a wider scale, but all that I have read and heard suggests that the HSD is getting there.

I don't think anyone is disputing that either system is bad.

Some interesting things when one looks at the GH database. It shows exactly what John is talking about.

The range of Prius II MPG is 35-71.8. The range of HCH II MPG is 31.8-60. This shows the greater ceiling of the Prius performance. Of course, the range or the median is not the best method to truly see which does better in terms of performance, since there are self-selected, non-equivalent groups. This really goes for any comparisons made from GH.

Wayne Gerdes of the hypermiling fame thought the Prius HSD system was grossly inferior to the Honda IMA system. After driving a Prius, learning more about it, and taking part in the marathon, he had a change of heart. A couple of posts in which he mentions his are post #23 and somehwat touched on in post #10.

 

one significant problem with hsd is the requirement that mg1 be active at all times at higher cruising speeds. this results in fairly significant losses of mpg at higher speeds. it is also the reason why the electric motor (mg1) needs to be water cooled. this is the main reason why daimler/chrysler and gm/bmw are looking into the two-mode hsd system. a second planetary gear set geared lower is used at higher highway crusing speeds. this problem generally isn't a problem in japan and the u.s. where highway speeds are significantly lower than europe. in this respect, the ima system is superior b/c extra power isn't sapped off the engine to drive the electric motor to balance the torque. there's an interesting discussion about this at this uk site that reviewed the prius (reader's comments at end are technically interesting:

http://www.evworld.com/view.cfm?section=article&storyid=887

here's a highlight from the article:

[/indent]"Some time ago, Mercedes identified in public the 'Achilles heel' of the current HSD, namely the losses that occur at higher speeds, with the generator needing to supply power to the motor via the controller even when the battery is effectively out of the picture. This has been one of the reasons why DaimlerChrysler has joined with General Motors to develop an alternative which is more efficient at freeway speeds. The maximum speed limit in the UK on motorways and dual carriageway roads is 70 mph, and most European countries have similar limits."

another potential problem with hsd is that the system cannot propel the vehicle if either electric motor goes out. while this is unlikely, it could happen in a 4wd hsd where too much load is placed on the motor while climbing a steep hill. one solution to this is to attach a third motor to the system to lessen the load. however, it should be noted that from an engineering perspective this is added complexity that technically shouldn't be needed. it's only there because the current design has a flaw.

having said all this, i believe the hsd system is a great system, especially for what it was designed for: the prius. the engineering requirements for the prius were: excellent mpgs for city/low speed driving; great mpg at us and japanese highway driving speeds.

 

Michael, rather than nitpick, I'll just agree with your post. But John's stance is that people should avoid IMA, having picked HSD as the winner years from now, never mind the best value in the interim if it deviates from the favored projection.

I say pick the best solution today. When tomorrow comes, pick the best solution then. If 2007 rolls around and I want to buy a car, and IMA gives the same FE and emissions as HSD, but is cheaper, I'll buy IMA. Regardless whether my hunch is that HSD might someday become the undisputed hybrid drivetrain. My crystal ball is murky on that point, and my engineering expertise is somewhat less than Honda. I'm all for smug self-confidence, but blind arrogance is not helping anybody.

I might want to hedge my purchase with an upgrade path .. but I doubt it. The price difference would have to be fairly small.

A bird in the hand is worth many in the bush comes to mind. This is doubly true in a competitive market economy, since trying to pre-select the future winner as a consumer by purchasing an inferior product short circuits the mechanism for tech advance for starters; but more importantly, it inhibits wide dispersion of the tech into society by keeping it more expensive.

I can already hear the screams: "HSD IS NOT INFERIOR TO IMA !!!"
Those people should read my post again. I am talking about a situation (that may or may not come to pass), in which two cars have equivalent functional value for me, but the IMA offering is cheaper than the HSD. The anticipated Fit Hybrid Vs Prius, circa 2007.

 

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 04:57 PM) [snapback]256743[/snapback]</div>

Why does it cause the problem when MG1 is active?
Why does it lose the mpg number when MG1 is active?

There are a lot of water cooled motors on the market.
Why is the water cooled motor not good?

I would like to see the real performance of the two-mode system on the market before discussing the pros and cons.

Ken@Japan

 

<div class='quotetop'>QUOTE(EricGo @ May 17 2006, 04:30 AM) [snapback]256748[/snapback]</div>

IMA is not the same. Choose whatever way to identify the systems you want, just don't put them in the same category. They have very different designs that clearly do not operate the same way.

In stop & slow traffic, HSD has proven a definite benefit. It doesn't take much searching to find quite few references of IMA owners complaining that the engine starts back up almost the instant they touch the pedal and doesn't shut back off again unless they first exceed 10 MPH. That's not the case with "full" hybrids, like HSD.

As for the "cheaper" reference, why are you dismissing Toyota's announcement about an upcoming lower price?

 

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 02:57 AM) [snapback]256743[/snapback]</div>

That's an interesting spin.

On paper, there are indeed losses... compared to a hypothetical machine. But in the real-world, I don't here much complaining about the MPG averages in upper 40's. That resulting electricity from MG1 isn't wasted as you attempted to imply. It is used to help improve efficiency.

As for water cooling, what the heck is wrong with that? Engines have required that for a century. The "assist" hybrids don't have that, so they have to limit how much the motor is used. HSD can use the motor all it wants, because it has way to deal with the heat.

The two-mode design intends to use clutches and a second PSD to provide the ability to halt some motor & engine activity. Again, that sounds good on paper (with respect to MPG, not price or complexity). But what will that actually translate to in real-world efficiency? Is it significant or just negligible?

 

The fact alone that both vehicles about match on mpg at high speed proves that hsd is superior and these "losses" either don't exist or are no worse than the CVT drive system. The superior car is obviously the one that is bigger and heavier and has a bigger engine, but still matches the mpg of the other.

 

And one would save still more thousands by buying a used car. If I were buying another new car it would be a Prius: fewer emissions, greater reliability, more interior room, more cool gadgets.

 

<div class='quotetop'>QUOTE(john1701a @ May 17 2006, 08:50 AM) [snapback]256782[/snapback]</div>

I most certainly will put them in the same category: cars. The drivetrain tech is a means to an end, not a reason in and of itself to buy a particular car. I am familiar with Prius' city operation, perhaps more than you are. I assure you, that when I go to purchase another car, it will be the one best suited to my driving conditions.

I recall a Toyota 'goal', and a Honda hybrid Fit rumor. Both are vaporware as far as I am concerned, and until I can buy one will only be a topic for conjecture. Which brings us back to this thread: Honda hybrid Fit vs Prius.

 

It is likely Honda won't introduce the Fit Hybrid.
They will introduce the New Dedicated Hybrid Vehicle in 2009 instead of Fit.
http://world.honda.com/news/2006/c060517MidYearCEOSpeech/

Ken@Japan

 

Complex is not the same as sophisticated, as this example shows.

 

<div class='quotetop'>QUOTE(EricGo @ May 17 2006, 08:56 AM) [snapback]256822[/snapback]</div>

So much for the long-term business success discussion...

 

<div class='quotetop'>QUOTE(EricGo @ May 17 2006, 09:56 AM) [snapback]256822[/snapback]</div>

And that, quite simply, is the way most people justify their car purchases. That's probably why the Prius and Civic hybrids sell well (huge with commuters I'd bet) and the HiHy, Rx400, and Accord Hybrid do not.

 

<div class='quotetop'>QUOTE(john1701a @ May 17 2006, 10:57 AM) [snapback]256853[/snapback]</div>

I have to admit, that I already find your core arguments flimsy, but at least I can follow a trail of reason. Snide trailing half sentences leave me completely baffled, I'm afraid. If you would like a response, or would like to show a bit of civility, try a coherent sentence. Or two.

 

<div class='quotetop'>QUOTE(ken1784 @ May 17 2006, 10:12 AM) [snapback]256838[/snapback]</div>

Interesting link. Thanks. The words on a new hybrid are at best cryptic, but one can certainly read it to mean a retooling of the current design. Whether that is instead of a Fit, unrelated, or the hybrid Fit was never slated for production in the first place is unclear to me. Perhaps there is a cultural translation here I am missing ?

I found most interesting that Honda is opening a solar panel manufacturing plant that will produce 34 mWh capacity yearly. That is GREAT news.

 

<div class='quotetop'>QUOTE(john1701a @ May 17 2006, 08:10 AM) [snapback]256791[/snapback]</div>

my mistake, i meant mg2, not mg1. granted, i haven't done a controlled test and my knowledge is coming second-hand from other sources albeit good ones. here is what chris ellis, a fairly knowledgable engineer had to say in response to a question regarding the energy losses:

<blockquote>" Ah! Now I see where your problem is. You are apparently claiming that the HSD ‘settles’ so that the rotor of the MG2 becomes stationary at a steady cruise. I think we are both in agreement that, at high road speeds, a significant torque must be applied to the MG2 rotor to balance the torque from the engine. This then means that MG2 is effectively stalled, but applying close to its maximum torque. You are correct in stating that no MECHANICAL work is being done by MG2 if it is stalled. However, any electrical engineer will tell you that applying a continuous high stall torque to most types of electrical motor is a surefire (literally) way of overheating it. Why’s that? - because the motor requires a considerable amount of electrical power to hold the stalled condition. As none of this energy is being dissipated mechanically, it must all go into heat, as losses from the system. Even if the field windings are water-cooled, the thermal build up in the rotor may become unacceptable, because there is no forced air cooling from rotation. Consequently, although simple theory may suggest the MG2 rotor locks up, in practice it is prevented from doing so by the HSD controller, to stop the rotor from melting down. The figures you demand have been widely published if you need them. On overall efficiency, I have already shared with Bill Moore some weeks ago photos I took of the underside of the Prius showing that, despite its sleek appearance topside, it really is an aerodynamic mess underneath. You might want to ask Bill to publish them! Toyota gets excited about a ‘low’ Cd of 0.26. GM bettered that more than fifteen years ago with the Opel/Vauxhall Calibra, of which tens of thousands were built. And the Precept hybrid prototype full-sized sedan achieved less than 0.17. The Prius is good but it could be made much better, relatively easily. However, it is up to Toyota to fix it, not me! I look forward to seeing just how these problems, and others, are addressed in the Prius III. </blockquote>

well, i think the issue here is the complexity of watercooling the electric motor. as pointed out above, the water cooling is there b/c of a flaw in the hsd design. water cooling mg2 is generally not needed except at higher load levels like providing a constant counter-balancing torque at higher speeds. i only point this out b/c it is easy to bash the ima or other hybrid systems and say that hsd is superior. most hybrid systems are complex and are tuned for specific operating conditions. hsd has not been designed for high speed crusing and/or off roading. it hasn't been designed for heavy vehicles like ones that mercedes and bmw create. it has been designed for the prius and the relatively lower speed city driving/commuting.

good question and unknown. i've read that daimler and bwm are worried about the complexity of the design and have other hybrid options in the works just in case. daimler has a parallel system more akin to ima in tests on buses and has hinted at wheel-mounted electric motors. i think the point is that there are a lot of different cars covering a lot of different needs. hsd is one. ima is one and we're finding that daimler, bmw and gmc may indeed come up with another system to meet the needs of their core markets.

 

<div class='quotetop'>QUOTE(tomdeimos @ May 17 2006, 08:32 AM) [snapback]256808[/snapback]</div>

wow, don't know what to say to this. this is convulted logic at best. the more efficient car is the one that is lighter yet achieves the same mpg as the heavier car. the prius' extra weight is due to the addition of two heavier motors and a necessarily larger battery pack to drive them. in other words, if one added a larger electric motor to the civic ima system and the equivalent batteries to bring it up to the weight of the prius, one would see much higher mpg resulting from the weight than for the equivalent prius. honda could achieve the same relative mpg as the prius without needing to carry around the extra weight from larger motors and battery packs. the consumer benefit of ima is the resultant savings in costs by eliminating the extra baggage thereby allowing the price of an ima civic to be significantly lower than a prius.

there is nothing magical about hsd that allows it to have larger and heavier electric motors and battery packs.

don't get me wrong. i love hsd and the prius but it's important not to be blinded into thinking that it doesn't have its limitations and/or that the ima system is inferior.

 

<div class='quotetop'>QUOTE(ken1784 @ May 17 2006, 10:12 AM) [snapback]256838[/snapback]</div>

I heard a report on CNN this morning that said that Honda is introducing a new hybrid, but "we don't have any other info on it." So I was thinking, well, isn't this typical of CNN- the news about the Fit Hybrid has only been out, what, several months now! But then I read this article. Doesn't change my opinion of CNN, though.