[ausev] Diesel hybrid

[evehicle4me at hischopsticks.org]

I have an idea that is by no means new.  I would like to buy a Dodge  
Caravan and install 2 electric motors in it, one on each of the front  
wheels - it is a front wheel drive.  (Alternatively I could dig up an  
awd van and put one motor on each wheel.  Even more preferable, if the  
fuel mileage numbers panned out I would love to find a full size van.)  
  I would like to put both batteries and a diesel powered generator in  
the van.  I would like the diesel motor to be purely for generating  
electricity, never to mechanically power the wheels.  My reason for  
doing this is to reduce the number of batteries (and thus cost and  
weight) needed to keep the van going and to extend the range.  I also  
want to use veggie oil for the diesel.  I would like to be able to  
drive the van indefinitely, i.e. not have a fixed range of 100 or 200  
miles as electric vehicles do.

I have a couple of questions.  Please feel free to refer me to other  
posts, url's or forums that can answer my questions.  I am sure they  
have been asked before but I have not yet figured out how to search  
very well on this topic.

How much can I expect to pay for a 25 hp electric motor?  I have seen  
new motors for more than $10,000 each.  Is it possible to find a pair  
of motors this size for $2,000 each (used)?  Wishful thinking :(  How  
much will each weigh?  The 4 cyl caravans only had 80 hp so I am  
thinking a pair of 25 hp electric will be  more than enough.

Electric motors seem to become proportionately more expensive as they  
get bigger, i.e. it is cheaper to buy 2  xx volt motors than to buy 1  
2xx volt motors.  Is this true?

Does someone have some kind of simulation software or spreadhsheet  
that I can use to model how many batteries I would need, how big a  
generator, etc?  This aspect of the planning has the most question  
marks and gives me the most opportunities to either sink or swim.

I have read that electric motors are significantly more efficient if  
kept running at a lower temperature, i.e. -20 F or lower.  Is this  
possible to do this for an electric motor used for a car?

I have seen some controllers for Chinese electric motors that adjust  
the speed of motors for turning radius.  Is this necessary?