Are you certain these 10,000 minivan hybrids are going to be Siennas? It sounds to me as though the 10,000 minivans are going to be sold in Japan, so I'm guessing they may be the smaller minivan (forget the name) sold in Japan.

Estima ... <grumble> <grumble> <grumble>

The last time I checked, it would cost us nearly $50,000 to import one. $35,000 for the vehicle, $10,000 for shipping and import duties and $5,000 for Japanese lessons. <grumble> <grumble> <grumble>

So one of my day-dreams:


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The tricky part is rotating the differential 180 degrees so we can drive forward. The other thought is the early VW vans had geared rear wheels. This would also reverse rotation at the cost of more rolling drag.

Bob Wilson

Estima and Alphard are possibilities. Sienna is getting a redesign for 2011 so I think it is the most likely candidate.

Panasonic EV Energy is 60% owned by Toyota, 40% by Matsushita, Panasonic's parent company. They're not going to starve their own child.

Toyota need a deal with the new owners of the NiMH patent, Samsung and Bosch's joint venture SB LiMotive, to allow larger NiMH batteries to be used in full EVs and plug-ins. My recollection is that some analysis has been done on how much capacity the battery needs in a charge-sustaining hybrid, which indicates that there are diminishing returns as you increase the capacity (hence size and weight) of the battery. Prius won't benefit much from a larger battery, unless converted to a charge-depleting, plug-in vehicle.

Li-Ion has an aging problem. The chemistry deteriorates with age, not just cycles. It also deteriorates more with higher discharge rates. Lithium-Cobalt chemistry, used in most laptops and mobile phones, has the high energy-density that's discussed, but it's not practical for EV use as it can't manage high power, which causes it to overheat. Lithium-Phosphate (e.g. A123's system) has lower energy density, though still greater than NiMH, but not by nearly as much.

The Prius HV battery only weighs about 40kg (Gen 1 and Gen 2). That's around 3% of the car's weight, and roughly what a child weighs. Savings from switching the battery to a lighter chemistry would be minimal.

More about Lithium Ion here.

The weight saving may be minimal with lithium but the space/volume should also be considered. With the need for flat floor for the minivan, the placement of the HV battery is critical. I wonder where the HV battery is in Estima and Alphard.

The big gain in switching to lithium-ion is efficiency. The roundtrip of energy in to energy out for NiMH can be as low as 60-70% at high currents, while modern LiIon can manage 95-98% efficiency. It would help harvest a lot more regenerative braking and require less cooling.

Bob,

That's one hell of a wet dream!

Here's a little something: Toyota Sienna Hybrid - Review | Hybrid Cars

You guys might've already read these but oh well, not everyone has.
Soccer Moms Rejoice! Hybrid Minivan on the Way. | Hybrid Cars

New Buick Hybrid SUV ­ Plug-In Hybrid Buick From GM - Popular Mechanics

HybridMinivan.net - Hybrid Minivans

A local hot rod shop used to modify big block V8s to rotate the reverse direction. It seems that speedboats use opposite rotation than cars. So rather than getting a reverse rotation propeller, they modified the engine instead.

Which leads to the question of whether you could modifiy a Prius drivetrain to rotate in the opposite direction. A custom cam would certainly be required. Maybe there is some way to reverse the connections to MG1/MG2. Oh, I got it. Switch to a positive ground system.:twitch:

You are comparing very old NiMH data and very late Li-ion one.

Ken@Japan

A Sienna hybrid would be one of my dream vehicles as well. I'm not in the demographic who would buy one but from a selling pov the maker that gets here first with a super fuel efficient family hauler will have a huge lead on the others. Odyssey? It only gets 22 mpg?..pfffttt.

However from what's been described in the HybridCars articles the prospective TSH ( Toyota Sienna Hybrid ) would have the same mechanicals as the current THH ( Toyota Highlander Hybrid ). In fact this makes sense since the two are almost fraternal twins...one has hinged doors and one has sliding doors. Also soon the Highlanders are going to be moved to Princeton Ind where the Sienna is built.

But 40 mpg out of the current mechanicals is WAY too optimistic. The current THH V6+HSD 4WD model struggles to get 30 mpg for long trips. In fact it suffers in comparison to the lighter and less costly Ford Escape Hybrid.

Putting the 3.3L V6 + HSD into a new 2011 TSH would make it an industry leader in fuel economy at about 27 mpg combined but it wouldn't set the world on fire; c.f. very modest THH sales. To me it would be a huge YAWN.

Now...all that being said if Toyota can link the new 2.7L engine to a new and improved HSD system then we're talking 230-ish HP and 35-ish mpg combined. This solves the dual problem of getting enough HP to the wheels to haul half a baseball team with all its gear while simultaneously getting eye-opening fuel economy numbers in the 35 mpg range.

There articles are getting the Sienna part wrong. It is indeed the Estima as others have said. Look at the text below from the article

Toyota Sienna Hybrid - Review | Hybrid Cars

"A larger version of the Estima is marketed in the U.S. and Europe as the Sienna. It’s likely that the Sienna Hybrid will be the first hybrid-power minivan on the American retail market, but Toyota has not announced a date."

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The Sienna is not a larger version of the Estima. They are not based on the same platform or engine, they are two wholly different vehicles. I would LOVE to see the Estima here in the US but Toyota things its too small for the US market and is hesitant to send it here. That being said they may make the US a hybrid Sienna but that would be a whole new vehicle that could go with the redesign of the Sienna.
The Sienna sold officially in the USA only.

I think the Scion xB is smaller than the Estima and a lot of xBs are on the road. Personally, I'd like to see:

• 1.5L Scion xB hybrid - for singles and older couples and youngest families.
• 1.8L Estima hybrid - for light-duty camping couples and growing families.
• 2.4L Sienna hybrid - for high quality camping, fuel-efficient, traveling couples and bigger families.

I don't care which one comes first because I've already got the clunker to trade in:

It is the one on the left. The right-hand one is my commuting car.

Bob Wilson

I agree. Especially, with the Japanese government rebates.

I don't think Panasonic EV is worried at all. The demand for hybrids is projected to increase well beyond global battery suppliers' abilities to meet demand. If you work in the auto battery business, your job over the next decade or two is pretty much guaranteed.
(In addition to what Mike Dimmick said)

I'm waiting for the day that hybrid and EV drivetrains become easily accessable to the public to convert current automobiles to hybrid and EV. Not just for classics (it is important that the original engine be stored in excellent condition next to the car, and can easily be reinstalled to keep the car 100% original), but also for people that own 1990s and 2000s ICE cars that want to convert them to a hybrid. For example, maybe someone with a $4000 2001 Honda Civic doesn't want to spend $18,000 for a new hybrid, but wants to buy a $3900 conversion kit for his current car. Sure, you can find individuals that will take a shot at it, but it would be nice to see a large, nationwide company offer conversions (and installation) to the public.

the world's most aerodynamic vehicle ever?

• 5.7L Sequoia Platinum 4X4 FFV 13/18 MPG - for families that don't plan for the future and never give thought to whether they will be able to afford to send their children to college in the future - and have never even thought about planning for their own retirement.

Looks like your "clunker" on the left is plugged in. Is it a hybrid???

Do you have up-to-date NiMH charging efficiency data?

The answers you seek can be found by comparing figure 1 (NiMH) with figure 3 (LiIon) in this paper:

http://umanitoba.ca/outreach/confer...s/PluginHwy_PHEV2007_PaperReviewed_Valoen.pdf

This is at very low rate (C/10), the losses would be much higher at higher rate, as used in the HEV scenario.