"Andrew Heggie" wrote in message
...
On Sun, 14 Dec 2003 16:09:02 -0000, "Badger"
wrote:


Austin Shackles wrote in message
.. .


the only thing that yer hybrid should allow you to do is to run an
internal
combustion engine at higher efficiency by limiting the rev range etc.

It does a bit better than that because the small engine works harder,
hence its volumetric efficiency is better, it then makes up for the
lower power of the smaller engine by drawing on the power in the
battery for short periods. The energy in the battery is in effect free
as it is recharged when the vehicle is slowing down. This is fine with
stop start driving and hilly areas but I wonder how the algorithm
works on a long motorway trek?

There is more too it than that....

The engines are different, particularly in the Toyota systems.

What most people don't realise is that manufacturers heavily tune their
engines to deliver punchy performance, at the expense of fuel economy, but
the Toyota engine's output is pretty limited (76ps) for a 1.5 - but it
doesn't need bags of power. The Toyota engine doesn't have a conventional
crankshaft either, in its set-up so that the power strokes have more travel
than the intake and exhaust strokes.

Also, different materials have been used, I believe the toyota engine has a
lower red-line, and the Honda engine has a special low-friction design.

Both cars have very low drag coefficients too.

at
which it operates. which is good, but it's always going to involve
fossil
fuels somehow.

Yes, not to mention lugging all that battery around, on a long run a
good diesel must be better.

is LPG has proportionally more Hydrogen than Carbon, however, water
vapour
is also a greenhouse gas.

But pouring more water vapour into the air does not increase warming,
in fact if it leads to more clouds the change in albedo could have the
opposite effect ;-)

I have tried to explain to Austin before. The point about water vapour is
that it is a strong greenhouse gas, most of it is formed by evaporations of
the oceans, and that increases with CO2 levels.

The greenhouse effect purely due to CO2 is minimal, its influence on water
vapour levels is key.

Of course the effect on the albedo is the main cause for contention, as
cloud simulations are quite difficult to do.

But human activities have almost no impact on water vapour levels (except
through CO2)


And what do you think happens to all those removed catalytic convertors
that
have all sorts of nasties in them when they get removed? Ah, good old
landfill!!!! LPG is currently the only commercially viable alternative
fuel
that IS cleaner than petrol or disiesel, hybrids still burn petrol

In principle the hybrid could be built with a SI engine running at
much higher (12:1???) compression ratio and using lpg. Presumably no
cat needed.

More worrying is what the depreciation will be, with a large battery
needing replacing at what cost? Every how many cycles?

Toyota ones are guarenteed for 8 years/100,000 miles, Honda for
8years/80,000 miles. They cost £1000 (Toyota) and £2000(Honda).

AJH