🚀 go-pugleaf

"BruceS" <bruces42@hotmail.com> wrote in message 
news:3c32da26-a43d-4f0d-a306-70c2e3699c7f@c19g2000vbb.googlegroups.com...
On Aug 14, 3:20 am, "Trevor" <tre...@home.net> wrote:
> "Sylvia Else" <syl...@not.at.this.address> wrote in message
> news:a8tm07Fup4U2@mid.individual.net...
> > On 14/08/2012 7:55 AM, Graham Cooper wrote:
> >> Electric Cars will need a 5 KILOWATT Engine
> >> (2 AIRCONDITIONERS WORTH OF POWER)
> >> NOT a 100KW ENGINE (50 AIRCONDITIONERS POWER)
> > The power requirements of a vehicle are not just a function of its mass.
> > At higher speeds, wind resistance is a major factor,
}This is particularly noticeable with bikes.  My fuel use on my bikes
doesn't really change much from having a passenger, despite the
substantial proportional increase in mass.  My smaller motorcycle
}weighs something like 200Kg, so even a 60Kg passenger affects the
acceleration.  OTOH, speed makes a huge difference.  Long stretches of
freeway speeds, which generally *help* cars vs. stop & go driving,
}reduce the bike efficiency.


For small capacity, high drag bikes. The opposite is true for high capacity 
low drag motorcycles.



> Pretty easy to make cars fairly aerodynamic at legal speeds these days.
}Of course that adds cost though, and may add mass as well.

Not at all, cars have steadily reduced their wind drag for decades, the 
trade off is more often things like storage space, access and practicality.


}Again with
the bikes, you'll notice that models really oriented at high speed use
}have a lot of fairings to clean them up aerodynamically.

Right, a "naked" bike is high drag, but there are very few "naked" cars on 
the road. And ones like the Ariel Atom aren't that bad because of their very 
low frontal area.



> >and won't be changed by making the vehicle lighter.
>
> You have to make the passengers lighter as well! That's the hard part 
> these
> days :-(
}No!  Just don't *have* passengers!

No need for a car then!


}As long as we're using super-
lightweight vehicles powered by solar cells, why not make them
completely remote-controlled, or better yet robotic, as well?  We
}could all settle back like Jabba, having everything brought to us
while we lose the need for movement.  Oh, and we could instruct our
electric robot cars to send angry emails to everyone while following
}some random car we've decided we should own.


One car with multiple passengers is almost always more efficient overall 
than one car per person, whether robotically controlled or not. Even staying 
home would still require delivery vehicles if you wish to eat.

Trevor.