I don't agree with you 100%. If the prius was such a poor candidate for plugin conversion, then those that have done it would not be getting the mileage they are.

Anytime you can supplement a power source with a second cheaper power source you are doing better. That is the benifit to the plugin conversions. If the best system is almost no battery, then the GM FAS or BAS or whatever it is called should be the ideal system.

The HSD works because it is a good balance of battery capacity and weight, but if the capacity can be increase with very little weight penalty, then the benifits could be reaped.

Besides, without people pusinh the envelope, you don't know what is truly possible.

The volt is a great concept, but the problem with that technology is you will always have conversion losses going from engine to electricity to motion. The HSD blends that capability by eliminating the electrical conversion losses when possible. That is why I think a plg-in HSD would be ideal. The only hurdle is keeping the engine from recharging the battery so you can charge it off of the power grid. Solve that, and you will have a real winner.

The plug-in conversion should get better miles/gallon because they don't use gallons of gasoline, but electric energy.
If I had $12,000, I would buy 4,000 gallons of gasoline and drive 160,000 miles instead of buying plug-in kit.

If a plug-in hybrid has 40 miles EV distance and our commuting is 20 mile one way, the plug-in is almost EV all year around.
Why do we have to carry heavy 1.5L(Prius)/2.4L(Camry) engine all yaer around.
What a wasting energy!
So, I'm saying an ideal plug-in is a series hybrid with a small engine.
You're absolutely right!
If you've more technical expertise than thousands of Toyota engineers, you may be right.
So, leave HSD alone.

Ken@Japan

One of the reasons I got the hybrid is my disdain for the middle east oil. I feel we are funding the people trying to kill us, so I would rather spend more and give it to people that are not trying to kill us than save some to give it to people killing us. I also got it to save money in general.


Because I commute 60 miles a day, and would still need the biggish engine especially since I commute at an average speed of 55 MPH. This means a series would be running very hard to keep the little engine producing enough energy to keep me going. And it would be doing that while incurring conversion losses the HSD does not.

The Toyota engineers have to comprimise so they can provide what 90% of the buying public wants. I don't. I can supply myself with exactly what I want, and it might not be what you want. That is fine, as I will be happy with what I have and you will be happy with what you have. They could have used lithium batterys, and gotten the same storage capacity with very little impact on trunk space, they did not. So to say it is perfect, is not giving credit to perfection.

As bob Wilson put it once, good enough is the enemy of perfection. Lets not settle with good enough, and keep working towards perfection.

I'm not sure I agree with this. Yes, there are definitely energy losses going from gas to electric. However, a hybrid's ICE does not always runs at the highest efficiency possible since it has to provide varying amounts of power based on load conditions. It also has to be sized large enough to provide adequate acceleration under high load conditions (e.g. uphill) when the SOC is low.

On the other hand the Volt's ICE only has to be large enough to generate enough electricity to recharge the batteries under the same high load conditions. I'm assuming that the ICE can be run at a single, highly efficient speed. It would charge the batteries and then turn off until the SOC has dropped enough to require charging.

I have no idea how it will work in a real world scenario, but I wouldn't be surprised if it outdid a comparably sized hybrid in fuel efficiency and emissions. Of course the batteries are still a few years away from commercial reality.

Toyota is developing a plug-in hybrid. My guess is it is coming in 2010.
It'll be a good competition between you and Toyota engineers.
You have only three years for your own conversion.

Ken@Japan

Or I could just upgrade in a few years, until then I will do some poking around in my spare time.

So if Toyota is releasing a plug-in, then they admit there is a benifit to it, and your statement "If you've more technical expertise than thousands of Toyota engineers, you may be right. So, leave HSD alone." is not exactly correct. The engineers might be very smart, but they design with-in the constarints they have. I just want a bigger battery, and a way to recharge it by means of an external powersource, and to keep the ICE from charging it past a certain point. I don't want to redesign the entire system, but only one power source to the system.

My bet is that Toyota's plug-in hybrid won't be HSD based.

Ken@Japan

Well, I tried to find the current limit and couldn't but did find a lot about preventing MG1 from overspinning by starting the ICE, so I'll withdraw my comment. I did find (to refer to a previous poster who withdrew a comment) a reference about only putting spark to "a couple" of cylinders at a time though on http://prius.ecrostech.com/original/...OnAsIDrive.htm.