CD Article: 2006 Honda Civic Hybrid and 2006 Toyota Prius

[wing]

I don't think it uses the Heat......... I think the original systems (prototypes) did use this or at least some said they did.  I'm pretty sure they use the flywheel to generate power.  IE, when you let off the accelerator, the flywheel continues to turn, this energy spins a generator to charge the batteries.  This seems like the least complicated solution.

[wing]

Well I was close, it's not the flywheel from the engine but from the electric motor, it turns inertia into energy.
http://www.hybridcars.com/renerative-braking.html

[davidm]

To capture heat and generate electricity there'd have to be a steam turbine on board.  The ultimate hybrid! 

[wing]

The editors have been informed

[Prius]

"both feature regenerative braking that captures heat energy, converts it into electricity"

Captures heat energy?    I guess the geek in me would like to know more about how this is accomplished. It must mean $pecial rotors and pads since that is where the heat is generated.  I would have figured that pressing the brake pedal would engage the motor to behave like a generator and thus slow the car down and recharge the batteries. Similar to engine braking except that being in generator mode provides resistance rather than compression).  This would also help explain another poster-owner's comment about lots of brake pad left.

Yeah, I guess Wing's got the site. The term "captures energy normally wasted as heat and convert it into potential energy stored in the battery" is a big confusing at first.

When you let go of the accelerator, eletric motors become generators and give that pseudo "drag" that you commonly experience with regular automatic cars. When you lightly press the brake pedal, on the Prius, it switches to the bigger, more powerful electric motor (50kW). The friction brakes are still out of play at this moment. The only come in around 10km/h or if you press harder on the brake pedal.

When you do a panic stop, regenerative braking is bypassed and you go straight to the friction brakes.

[Rupert]

  The fuel savings of hybrid vehicles are impressive taken from the actual experiences of owners in the main. I am new to the subject and am trying to bring myself up to speed with the technology. From previous contributions to this debate and personal research I now know that battery charging occurs on the fly as well as under braking. The braking part being the conversion of kinetic energy to an electric charge in the battery through a generator. Charging the battery on the fly is surely not achieved by surplus power that would have been wasted; it takes power and thus gasoline to drive the generator and charge the battery. This being as it may, the overall package seems to work and if you consider that the Prius gets considerably better mileage than my smaller non-hybrid vehicle that weighs 600 LB. less, it works very well. At this point trying to justify vehicle cost by applying fuel savings is not important. The object should be to produce a product that is ultimately financially feasible to everyone; thus reducing the consumption of non renewable resources. In the past volume production has achieved that for us.
  Further I now know that a different kind of gasoline engine is used based on the Atkinson Cycle. However I find this somewhat confusing. The Atkinson Cycle engine it seems to me performs the Otto Cycle in one rev of the crankshaft not 2 revs. Am I right in saying that the engines used in hybrid vehicles are in fact conventional, with the usual crankshaft arrangement but with modified valve timing to achieve a reduced charge by expelling some of the charge gasses into the inlet manifold. Thus only simulating the Atkinson cycle. Perhaps the Atkinson Cycle should be called the Atkinson Linkage which actually performs the Otto Cycle albeit with a longer expansion and exhaust stroke. The longer expansion stroke extracts more energy from the charge gasses and presumably reduces heat losses. Are there any automobile engines that use the Atkinson Linkage. It appears to be cumbersome and may not be applicable to automobiles.
  Thanks for reading my blog, I welcome any replies.

[Prius]

Yeah hybrids use a regular engine. Some of them use the Otto Cycle, others use the Atkinson Cycle. The Atkinson Cycle does both expansion and compression in one revolution. This allows for better use of fuel but has lower output. Mazda overcame this with a supercharger on the Mazda Millenia (Miller Cycle). Toyota took this and used an electric motor to supplement the engine. So far only the Prius, Escape Hybrid and Camry Hybrid use the Atkinson Cycle.

[Rupert]

  I'm still not clear on this. If a regular crank is used it will take 2 revolutions to achieve the Otto/Atkinson cycle and the crank will not allow a variation in the suction and expansion strokes. It seems to me that a longer expansion stroke is the main point of the so called Atkinson cycle. It's the Atkinson linkage that appears to achieve this or have Toyota designed a different and more compact mechanical linkage.

[Prius]

does this help?

http://en.wikipedia.org/wiki/Atkinson_cycle

[Rupert]

  Thanks for the reference. The Atkinson gas engine was made by Messrs. Manlove and Alliott around 1906 to 1910 and although being more efficient than engines working on the Otto cycle, it was not a commercial success due to the excessive wear on the toggle joint crank linkage mechanism which produced the variable length suction and expansion strokes. Since no one has been able to come up with a suitable improved linkage in the last 100 years it might be that the Atkinson engine itself will remain on the side lines.
  However, as I see now, the Atkinson cycle has been achieved in conventional engines by valve timing. The inlet valve is allowed to stay open at the beginning of the Piston up stroke to push some of the gas charge back into the inlet manifold chamber. Thus the longer expansion stroke is effectively achieved by reducing the charge. A kind of back door method you might say. The torque on the crankshaft is reduced due to the smaller bang and reduced pressure on the piston but more energy is obtained from a given weight of gas due to its greater expansion. The engine therefore is more efficient but less powerful for a given capacity and weight. Being able to charge the battery when the engine is running at its most efficient RPM is a bonus. Even with the relative weight disadvantage the overall package seems to achieve its goal but it is complex.
  Thanks for reading my submission.

[geep]

Are the battery packs in the Prius and HCH pro rated while under warranty? If a battery fails in year 7 of the 8 year warranty will you get 100% coverage?
I am trying to decide upon a gas Civic, hybred Civic or Diesel Jetta...tough choices, have researched the topic `til I am sick of it and still LOTS of unanswered ??s
Most of the miles will be highway driving and I have crunched costs vs fuel savings numbers over and over and really the numbers point to a gas Civic as being most economical, but I like some of the options the HCH provides that you cannot get on a gas Civic

[wing]

Hybrids are more efficient in the city if you are doing mostly highway miles you are better off with a Gas or Diesel vehicle.    In most cases economically it doesn't make sense to go Hybrid it is more of a environmental reasoning or statement than a financial statement.

[Prius]

Depends. The HCH is rated 4.7L/100km city and highway. That's marginally better than a regular Civic with a manual transmission. Are you looking for basic transportation (e.g. Civic DX) or a car with low emissions, better fuel efficiency and more comfort features?

Also, isn't it the point of a warranty? that it'll be replaced if within the specified period? I believe Honda's warranty is slightly less than Toyota's (140,000kms vs. 160,000kms).

Besides, the batteries are never fully charged or discharged unlike cellphones or laptops so they'll last longer. You live in SK? I don't think there's any incentives there are there? Cause in BC or ON, we get $2,000 off. That puts the HCH closer in line with the Civic EX automatic.


You need to recalculate your numbers to include other stuff besides fuel. Items such as brake pads (brake pads last longer because of regenerative braking), no power steering fluid to replace (electric power steering assist), maintenance costs between Honda and Volkswagen (and their service intervals), winter startup - gas vs. diesel. That's all I can think of atm.

[wing]

In Ontario it says Maximum $2000 what does that mean?  Does it vary based on income?

[si]

In Ontario it says Maximum $2000 what does that mean?  Does it vary based on income?

I understood that means you get the maximum value of up to 2 grand off the PST.

[Prius]

ya probably. Like here, it used to be $1,000 or 30% off whichever is less up to... some upper limit. I think it's $40k or something like that. But with this $2,000, I can't remember what the exact words were but I remember saying to myself that the Insight doesn't get the full $2,000 but the Prius and old HCH does. In that case, the new HCH may not get the full $2,000 rebate but a portion of the PST smaller than $2,000. Take a look at the Price Your Car Sheet or equivalent. It's usually shown on that on the window sticker.

[geep]

ya probably. Like here, it used to be $1,000 or 30% off whichever is less up to... some upper limit. I think it's $40k or something like that. But with this $2,000, I can't remember what the exact words were but I remember saying to myself that the Insight doesn't get the full $2,000 but the Prius and old HCH does. In that case, the new HCH may not get the full $2,000 rebate but a portion of the PST smaller than $2,000. Take a look at the Price Your Car Sheet or equivalent. It's usually shown on that on the window sticker.

So why is this a provincial incentive instead of a national? Really makes you wonder if Canada is concerned about energy, environment etc! I can easily see the HCHs in western Canada being loaded on to transports and shipped to Ontario

[jonl]

Seems like pretty poor gas mileage on the civic, "381.6 kilometres per tank".  That's not good at all.  If I drive very, conservative I can get 487 km per tank on my 2003 Civic (non hybrid), in summer.

I can't find this in the article.  I do see 4.7/4.3 L/100km.  With a 45 liter tank, theoretical range would be close to 1000 kms per tank.  Though no doubt real-world consumption is not as good, and nobody runs their gas tank dry. 

My reasons for preferring not to buy to diesel in North America include:
- not wanting to choose from a very limited selection (VW, Mercedes)
- not wanting to search for stations that sell diesel fuel
- lousy quality fuel that adversely affects vehicle performance and life
- increased cost over equivalent gasoline engined models (though less of a premium than hybrid)

Regardless, there are lots of vehicles that get astonishing gas mileage, and with gas near $1.00 / liter, we're seeing more all the time.  Personally, I'd prefer to buy a Fit / Yaris / Corolla / (standard) Civic and get great mileage, for many thousands of dollars less, without the hybrid question marks of reliability, maintenance, resale value.

[si]

Would it be possible to make a diesel-battery hybrid?


I know there would be cons, like cold engines and junk, but if it worked it would save even more gas!

[Prius]

There are limitations and I can't remember what they are though in theory, a diesel hybrid should work fairly well.


I don't see the point of all the hybrid reliability and such. They've been... wait.. the Prius has been around since 1997 and Honda's Insight has been around since 1999. But then again, I can't justify your claim with regards to the domestics since they've entered only recently.