Toyota salesman claiming 2010 will get 1.8 L engine

[spwolf]

Panasonic is leading battery manufacturer in the world, so you can rest assured that whatever battery tech Prius gets, it is going to be state of the art for that time... Otherwise, what other NiMH batteries last as long and can be recharged as long as Prius?

[sproven]

Originally Posted by drees

So Wikipedia says that a typical NiMH cell loses 5-10% of it's capacity after the first 24 hours due to self discharge.

This sounds high to me based on experience with consumer grade AA NiMH cells. Perhaps I'll have to run some actual tests to verify.

Regardless, I assume that the 5-10% after the first day is on a fully charged battery. Since hybrid very rarely sees a completely full battery, I don't think that this particular characteristic is all that important. If we were talking about batteries for a PHEV, then yes, it may be, but then again, you'd typically leave your PHEV plugged in until you're ready to use it. And even then, to maximize battery life you would avoid fully charging the cells.

The existing battery in the Prius does not use low-self discharge technology.

So again, I think that any improvements in battery technology will be in reducing the internal resistance and increasing maximum power output of the pack.

Currently, the generators in the Prius could pump out about 67hp, but are limited to about 30hp because of power limitations of the battery pack.

The current Prius is using battery technology from the year 2000. NiMH battery technology has improved significantly since then (back in 2000 you could only get ~1500mAH AA cells, now you can get cells with about double that capacity).

I did think that perhaps the initial self-discharge might only happen from full charge, but I don't know that to be true. It's certainly plausible.

I use a lot of NiMH AA batteries for powering GPS units and the amount of energy wasted keeping the batteries topped up continually is not good. I recently started using low self discharge batteries and it means I don't have to waste energy keeping them topped up. I can charge them ahead of time and be confident they will only lose a small amount of energy.

I would think that I high self discharge in the first 24h could be a concern if you are using the car maybe only every other day or so. You have to replace that 5-10% from somewhere, and it comes out of your pocket. However I worked out at our petrol prices (about £1.15 a litre) even if you lost 10% of the total rated capacity that's only about 100Wh. Assuming only 50% efficiency that would still only come to about 2p in petrol costs.

I can't quite decide if I want a Prius or not. I almost bought an 08 model but I think if you are only doing 5K miles a year then the cost/benefit ratio isn't so good. My 12yo car is also capable of over 40mpg (US gallons) and getting a little bit more but using a lot of resources to do so doesn't seem that clever at the moment.

[catsbox]

Originally Posted by sproven

I can't quite decide if I want a Prius or not. I almost bought an 08 model but I think if you are only doing 5K miles a year then the cost/benefit ratio isn't so good. My 12yo car is also capable of over 40mpg (US gallons) and getting a little bit more but using a lot of resources to do so doesn't seem that clever at the moment.

IMO, it is not about the cost benefit ratio. It is about reducing dependence on oil. It is about reducing emissions. It is about reversing the fuelish extremism that predominates in the US. The Prius is the first step towards a fully electric/alternative engine. Money is better spent on other things, like clean fuel sources.

[sproven]

Originally Posted by catsbox

IMO, it is not about the cost benefit ratio. It is about reducing dependence on oil. It is about reducing emissions. It is about reversing the fuelish extremism that predominates in the US. The Prius is the first step towards a fully electric/alternative engine. Money is better spent on other things, like clean fuel sources.

Sure - US or UK (where I live) oil dependency is a big problem. But I do 5K miles by bicycle (actually this year I might even hit 7K, I already have 4360 miles logged), and ~5K miles by car. If I bought a Prius to replace the 5K miles done by car then I don't know that I'd ever recoup the energy cost (that's what I really mean by cost/benefit) of the new car. The old car still works, it's a lot smaller and simpler than the Prius. We're not talking Hummer vs Prius here.

Once it gets to the point of the old car being beyond economic repair then the equation will balance up a bit, since it will need to be replaced. That's one reason why I'm interested in seeing what the 2010 model will be like because I think my car might just about manage to last that long. Or it might not.

(Sorry for the thread hijack, it's gone a bit off course now)

[miscrms]

Originally Posted by PriusSport

If they aren't going to Li ion batteries in 2010, the changes will be essentially cosmetic. The Gen II car is almost perfection--in its 4th or 5th year of production. I don't see how they can call the 2010 Gen III unless they change the battery system fundamentally.

Sorry but thats just silly. The 2010 is being redesigned from the ground up as a completely new car. What difference does it make what kind of battery is in it? Anyone who has spent some time looking at it quickly realizes that for HEVs, there is very little advantage to Li-ion over NimH anyway. HEV performance is not a strong function of battery capacity. People have doubled the capacity of the Prius battery and it makes almost no difference. The US Gov found that even with the battery capacity degraded by 1/2 there was little if any difference in mileage (gen 1 @ 160k). Taking advantage of Li-ion's specific energy density to cut the weight of the battery modules in half would save you a whopping 32 lbs. If you can improve specific power or lower resistance that would help, but the modules in the Prius are no slouch at 1.3kW/kg. That rivals many Li-ion battteries. Particularly as a Li-ion pack of the same capacity and half the weight would have to have double the specific power just to put out the same current.

My biggest hopes are that they can take what they have learned from the Camry and Lexus hybrids to improve the Prius' regen efficiency and lower emissions. The fact that the GS450h and RX400h have lower tailpipe emissions than the Prius is a little embarassing As far as the engine size, as others have indicated there is lot more going on in the Prius than just displacement. A newer, more sophisticated 1.8L could easily be more efficient than an older 1.5L. Beyond that the key in an HSD is matching the engine properly to the rest of the system so that it stays in its peak efficiency range as much as possible. A smaller engine working harder to supply the required power could easily be less efficient.

Sources have indicated that the new design is taking Li-ion and the plug option into account, so when the time is right they can transition to the new pack without another major redesign.

Rob

[Flying White Dutchman]

Originally Posted by miscrms

Sorry but thats just silly. The 2010 is being redesigned from the ground up as a completely new car. What difference does it make what kind of battery is in it? Anyone who has spent some time looking at it quickly realizes that for HEVs, there is very little advantage to Li-ion over NimH anyway. HEV performance is not a strong function of battery capacity. People have doubled the capacity of the Prius battery and it makes almost no difference. The US Gov found that even with the battery capacity degraded by 1/2 there was little if any difference in mileage (gen 1 @ 160k). Taking advantage of Li-ion's specific energy density to cut the weight of the battery modules in half would save you a whopping 32 lbs. If you can improve specific power or lower resistance that would help, but the modules in the Prius are no slouch at 1.3kW/kg. That rivals many Li-ion battteries. Particularly as a Li-ion pack of the same capacity and half the weight would have to have double the specific power just to put out the same current.

My biggest hopes are that they can take what they have learned from the Camry and Lexus hybrids to improve the Prius' regen efficiency and lower emissions. The fact that the GS450h and RX400h have lower tailpipe emissions than the Prius is a little embarassing As far as the engine size, as others have indicated there is lot more going on in the Prius than just displacement. A newer, more sophisticated 1.8L could easily be more efficient than an older 1.5L. Beyond that the key in an HSD is matching the engine properly to the rest of the system so that it stays in its peak efficiency range as much as possible. A smaller engine working harder to supply the required power could easily be less efficient.

Sources have indicated that the new design is taking Li-ion and the plug option into account, so when the time is right they can transition to the new pack without another major redesign.

Rob

maybe a new design 1.5 or even maybe all new 1.2 will be better then a 1.8
wy not make a all new 1.2? better then the current old 1.5

[spwolf]

Originally Posted by Flying White Dutchman

maybe a new design 1.5 or even maybe all new 1.2 will be better then a 1.8
wy not make a all new 1.2? better then the current old 1.5

or why not design new 1.8 that is better than current 1.5?

Small engines are not at home at highway - they have to run at higher rpm, which means bigger consumption. Thats why they made it 1.8.

[donee]

Hi All,

RPM is not the whole story. Cylinder size effects efficiency, due to the finite size of molecules, and rates of burning effected by the molecule sizes and density. I am no expert, but there is probably an optimum cylinder size for low-altitude combustion. Fewer parts are cheaper. So why do they make V6s and V8s ? Its probably to be able to keep the speed of the piston up fast enough to work with the combustion.

But, most likely the reason they made the engine 1.8 liter is so its a common block with the Corrola and Matrix. Toyota is known for putting together cars with common parts amoungst several cars. This reduces the cost of the parts. Engine blocks are very scale dependant parts. One article I read is that Toyota had like 1/4 th the seat rail part numbers than Chrysler. At the time of the design, the Yaris was not known to be as high a volume car as the Corrola and Matrix. Does anybody know if the Pontiac Vibe uses the Toyota 1.8 liter engine ? If so, that would be a clincher.

If they were going to do an engine specifically for fuel economy, one might see a 3 cylinder 1.5 liter. But, it would be a custom engine only used in the Prius, and as such probably add 2 or 3000 dollars to the Price.

[drees]

Pontiac Vibe is basically the same car as the Matrix with different sheet metal, so yeah, the engine should be the same, too.

[Flying White Dutchman]

Originally Posted by spwolf

or why not design new 1.8 that is better than current 1.5?

Small engines are not at home at highway - they have to run at higher rpm, which means bigger consumption. Thats why they made it 1.8.

the current prius runs between 1200-2200 rpm on the highway
dont think that is high for a 1.5