OT: Hybrid cars

[guy keren]

On 09/16/2013 10:28 AM, Oleg Goldshmidt wrote:
> guy keren <guy.choo.keren at gmail.com> writes:
>
>> actually, driving at 70-80kmh is usually MUCH MORE fuel-efficient then
>> driving at 110kmh, in most cars and under most road conditions...
>
> This may *still* be true for many cars on Israeli roads, but it should
> not be regarded as some law of nature or engineering, and it is not a
> universal constant. Chances are, it no longer holds for many newer
> models (or for any: I'd say the sweet spot was around 90km/h 10-15 years
> ago for family-sized cars). The exact number is less important than the
> dynamics, in my mind. So let's consider how it evolves.

instead of going into theories - does your car have a fuel consumption 
computer?

if it does - please perform an experiment:

reset the counter before your next two drives on the highway. on the 
first drive - drive at 110km/h. on the second drive - go at 80km/h.

perform the two tests on a flat area outside the city (i.e. reset the 
counter when you're outside of the city).

then come back with the results.

i did this in the past, both on the Prius (2008 model) and on a renault 
megan (2000) - the difference was noticeable, in favor of the slower speed.

when you perform a similar experiment in europe (again, with a computer 
that measures fuel consumption), with a european car - then we can 
figure out whether these theories agree with reality.

--guy

- in theory - there is no difference between theory and practice.
   in practice - there is.