Dragaera

FW: Petrol Prices

Howard Brazee howard at brazee.net
Wed Mar 23 04:52:08 PST 2005

Peter H. Granzeau wrote:

>> That's what trains and many busses are.   They just don't turn off
>> all the way.
> 
> Trains use Diesel to turn a generator; the actual drive to the wheels
> is electric motors.  Busses use Diesel via an automatic transmission.

There are hybrid busses too.   That's why I added the qualifier.

> In either case, the engine idles when the vehicle is temporarily
> stopped.  Gasoline hybrids don't do that, when the car is at rest, the
> engine is stopped.

That's what I said.
 
>> Googling, I see that current prototypes of cars such as the Civic
>> hybrid aren't much more efficient than gasoline models, and not as
>> efficient as natural gas.   But diesel is available at the pumps.
>> 
>> When you need to charge batteries, a constantly running generator has
>> advantages over one that starts and stops a lot.
> 
> Nevertheless, that's not how hybrids do it.  The battery pack is
> charged only while the car is in motion.  When a stopped car starts
> up, the battery is the sole source of power for a few seconds.  Some
> small amount of electricity is recovered when the brakes are applied
> (I forget the term for this).

I suspect that's not how hybrid diesel cars will do it.   We'll see.