Prius Killer - Hybrid Honda Fit?

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 10:43 AM) [snapback]256877[/snapback]</div>

People cruise along happily in a Prius at 75 MPH without any trouble at all, for hours at a time. How can you possibly make a claim that the design was not intended to support that, despite the fact that it operates just fine that way.

Stop feeding that misconception.

 

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 11:43 AM) [snapback]256877[/snapback]</div>

Talking about convoluted logic this is where you are even farther away from the facts. A stalled motor doesn't heat any more than a moving motor and your reference makes no sense at all about extra heat generation. Heat generation depends only on the frequency and the current and so a stalled motor should have lower losses needing only steady DC current.

It is true a stalled motor on the power line will overheat because it will draw more than it's design current but this has zip to do with the Prius HSD. Current is what determines torque, and it is controlled to match what the engine needs and it is true there are losses but it is no different at high speed vs low speed except as the tourqe need is different. It would be more correct to say it depends on the power or acceleration needed. Has nothing to do with whether the shaft is turning or not.



<div class='quotetop'>QUOTE(neilb @ May 17 2006, 12:06 PM) [snapback]256896[/snapback]</div>

Then following your logic it should be easy for GM to make Hummers or Tanks that get the mpg of a Honda.
Completely the opposite from reality. The main reason most people like the Prius over the Honda may be the battery location issue, but second to that it is clearly because the Prius is more roomy and still getting better performance and at least as good mpg.

Anybody can make a small underpowered car that gets great mpg. Geo Prism used to do great with their superior design by your logic.

 

<div class='quotetop'>QUOTE(john1701a @ May 17 2006, 12:31 PM) [snapback]256919[/snapback]</div>

He said it wasn't designed for it, not that it wasn't designed to support it. There's a distinct difference.

 

<div class='quotetop'>QUOTE(tomdeimos @ May 17 2006, 11:44 AM) [snapback]256924[/snapback]</div>

i'm only quoting a more knowledgable automotive engineer. the discussion at the link i provided in quite interesting. even engineers who are prius fans admit the archilles heal. i don't think there's any problem with that. hsd is not designed for european highway cruising speeds. that's okay. it was designed for the us and japanese markets. it does great at our highway speeds and even better at city speeds. hsd doesn't have to be the be-all-end-all to be great. jeez.

do you understand my point about electric motors/battery packs and weight? the added weight on the prius is certainly from the extra/bigger motors and the larger battery pack. adding those equivalent parts to a honda civic would increase both its power and also its mpg. honda didn't need to do it to meet the same mpg as prius and instead passed the savings onto the customer.

regarding your point about the level of effort to get great mpg: it is very difficult to make a small car with great mpg on par with the civic/prius. hence the reason there are not any on the road.

 

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 02:08 PM) [snapback]257002[/snapback]</div>

I have a quibble with this remark
There are lots of small non-hybrid cars on the road getting FE in the high 30's, low 40's. But not in the US. To a certain degree, hybrid tech is a solution for oversized cars. This is why I am so interested in the possible Honda Fit hybrid. I so much want to see hybrid make small cars even better, not just make big cars less of an ecological eyesore.

 

<div class='quotetop'>QUOTE(EricGo @ May 17 2006, 01:26 PM) [snapback]257018[/snapback]</div>

point taken and i agree with you: more mpg not power! i was only trying to counter the claim that was made: that its not difficult to create smaller cars with great mpg. the implication being that the civic's ima system isn't in fact adding much to its mpg. this is in fact not true. drivers are getting around 32mpg combined in the non-hybrid civic. drivers are getting 46mpg combined in the exact same car hybridized. that's a 47% improvement in fuel economy that the ima system delivers. according to the epa numbers, the camry hybrid gets 39mpg combined and the non-hybrid camry gets 27mpg combined. that's a 44% improvement with the hsd system.

conclusion: ima delivers same level of improvement in mpg results as hsd (i believe in fact that the real world results when they come in the for the camry hybrid will be slightly less than the epa results and therefore the hds improvement factor will drop slightly.)

 

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 11:08 AM) [snapback]257002[/snapback]</div>

I never considered the Honda Insight to be a big car, yet it gets great gas mileage.

 

I read in the business news this morning that Honda was building a couple of new plants in the US. None were for the Honda Fit, but were instead to manufacture a new model. The new model is a small hybrid car that Honda was coming out with in 2009. Can anyone confirm ? I'll try to find that info and paste it here.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ May 17 2006, 12:41 PM) [snapback]256980[/snapback]</div>

He said it wasn't designed for it, not that it wasn't designed to support it. There's a distinct difference.

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That's a great example of undermining, an obvious attempt to divert attention. And you didn't even bother to explain the difference.

HSD fulfills a wide array of consumer requirements. What are you denying?

 

<div class='quotetop'>QUOTE(john1701a @ May 17 2006, 06:19 PM) [snapback]257174[/snapback]</div>

I can't believe you actually need me to explain the difference... but here we go..

"Doesn't support it" means it can't do it.

"Wasn't designed for it" means it can do it, but not optimally.

Nobody here denies that HSD is at it's best during city cruising. And nobody here can deny that on the highways IMA and HSD achieve similar mileage. Hell, even the Accord Hybrid (before they porked it up), during it's first year on the market, was rated 38MPG highway, the same mileage as the Camry hybrid is rated for on the highway.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ May 17 2006, 05:39 PM) [snapback]257187[/snapback]</div>

I asked what "wasn't designed to support it" meant and instead you provided the definition for "Doesn't support it". That's undermining.

Goodbye.

 

<div class='quotetop'>QUOTE(Karnac @ May 17 2006, 06:04 PM) [snapback]257135[/snapback]</div>

Are you reffering to this article?

"On a global basis, Honda will introduce an all-new, more affordable, dedicated hybrid car to be launched in North America in 2009. This new hybrid vehicle, to be produced at Honda's Suzuka plant in Japan, will have an annual North American sales volume target of 100,000 units (200,000 units worldwide) and a target price significantly lower than the current Civic Hybrid."

 

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 11:43 AM) [snapback]256877[/snapback]</div>

First, Prius was not designed for off roading. Prius was designed to go 105 mph top speed. With minor modification a stock Prius went and set the hybrid speed record of 131 mph.

The fact that Lexus GS450h has top speed of 131 mph already proved you wrong. Lexus RX400h top speed is 124 mph and it competes with BMW X5 V8 and Mercedes ML V8. HSD can adapt to different need fairly quickly. Since introduction of Prius in 2004, in two years you are seeing so many configurations on the market already.

What about IMA? When will we see Acura hybrid? Can IMA be designed to work effectively in bigger car that Acrua line up has? We have yet to see and the first attempt (Accord hybrid) failed.

It is not right to copy and paste an engineer's statement about specific HSD implementation and say, "HSD has design flaw and can't do 1) 2) 3), etc..." HSD in Prius does exactly what it was intended to do.

Dennis

 

<div class='quotetop'>QUOTE(neilb @ May 17 2006, 12:06 PM) [snapback]256896[/snapback]</div>

Prius' size is between Corolla and Camry. Prius also weights between them. Your logic can be applied if there is a Corolla HSD. But there isn't and you are comparing a bigger and heavier car to a compact car. Remember, HSD does not have mechanical CVT that IMA has. With the bigger MG1 and MG2, the size is about the same as equivalent IMA already.

If IMA's electric motor can be made bigger, why isn't Honda doing it? If I remember correctly, Honda is using the electric motor as a flywheel. If the electric motor is too heavy, I am not sure of the consequences.

Dennis

 

<div class='quotetop'>QUOTE(Jonnycat26 @ May 17 2006, 01:41 PM) [snapback]256980[/snapback]</div>

Ok, so if HSD is not so efficient in high speed, why Prius still get better mpg than comparable cars or even smaller IMA hybrids (HCH)? Looks like HSD worse case is better than IMA best case in the same situation. Can IMA out do HSD in city? QED.

HSD in Prius does a pretty darn job at efficiency already. There are always trade-offs in every designs. It is just that a better design has more absolute advantages.

Dennis

 

<div class='quotetop'>QUOTE(EricGo @ May 16 2006, 09:31 AM) [snapback]256306[/snapback]</div>

I'm surprised nobody commented on this earlier (especially John): If the "two cars" you are refering to are the Prius and the HCH, the ability (or inability - HCH) to drive the car without turning the engine, is definitely NOT a marketing decision. The HCH ties the single motor-generator to the engine, so one cannot turn without both turning and the car cannot go without the engine turning. (Unless you put it in neutral and roll it downhill!)

In contrast, the Prius, with its HSD, allows the car to be driven in electric mode while the engine remains stationary, up to 42 mph; and that limit is related to the PSD geometry and MG1's design specs, and could be raised or lowered with different specs. John has some very nice animated schematic pictures on his web page showing how the PSD accomplishes this. (By driving MG1 backwards, and MG2 forward, the engine can remain stationary while the car moves forward. Nothing of the kind is possible with the HCH.)

Having said that, the Honda is an excellent car. It's just nowhere near as elegant as the Prius. And I'll agree with John that IMA really has nowhere to go, while HSD has potential to be refined to something much more advanced. -- But I would not entirely rule out the possibility that Honda may come up with a worthy competitor to HSD at some time in the future. How about a pure serial hybrid with 4 independent motor-generators on the 4 wheels and a 30-mile plug-in range with a gas engine + generator for longer drives? If Honda were to put that inside a Civic body and make it a liftback it could compete with the prius!

 

<div class='quotetop'>QUOTE(john1701a @ May 17 2006, 07:04 PM) [snapback]257195[/snapback]</div>

Actually, I provided both definitions. You have to read beyond the first sentence.

 

<div class='quotetop'>QUOTE(daniel @ May 17 2006, 08:38 PM) [snapback]257243[/snapback]</div>

The limited ability of the HCH II to glide compared to Prius is known (although driver ability plays into it, just like with the Prius). I was talking about coasting and regen modes.

At this point, after driving Prius for 18 months, I don't know if I am trained, or the design is naturally intuitive, but slowing/coasting/power as progressive pressure on the fuel pedal is applied works great. I do remember hearing lots of people complain about the design though, saying that regen slowing should occur with a foot on the brake, not on the fuel pedal. After thinking about it a bit, I imagine the design caters to drivers with a feather touch -- either natural or acquired. For sure, the design forces me to look at the MFD to be sure I am coasting.

do not know. Sounds like a trade-off. One I like overall.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ May 17 2006, 07:52 PM) [snapback]257251[/snapback]</div>

Perhaps this has inspired some to find out what the whole story is, to search for past confrontations. There's far more actually at play here than the first impression gives.

Being vague & ambiguous. Attempts of all kinds to alter focus of the discussion. Ignoring the long-term & big-picture. Making it personal to avoid objectivity... we've heard it all before over the years. You have a very extensive history of that here, the other Prius forum, and especially on Edmunds.

But now that this has been revealed, nothing else needs to be said. Those older topic threads speak for themselves.

 

<div class='quotetop'>QUOTE(john1701a @ May 18 2006, 12:09 AM) [snapback]257321[/snapback]</div>

This is useless innuendo. In this thread he has made reasonable points that a civil person can debate or agree with.

Sheesh. Even over at FHOP, witch hunts are rare. This is a Prius owner's group, not a church of rabid zealots. If you please. I can't help but wonder if John views himself as a high priest, come to cleanse the faithful from heretics.