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# Re: [Phys-l] gasoline

Yes our driving is at 55 mph. We do this intentionally.
The 62 mpg was on a several of occasions.

We used to get mid 50's and now is the upper 40s which is about a 10% decrease. We've been driving the Prius for 5 years now.

Why was it assumed that a he drove the car? Just curious about the assumption.....

Sheron

----- Original Message ----- From: "Bernard Cleyet" <bernardcleyet@redshift.com>
To: "Forum for Physics Educators" <phys-l@carnot.physics.buffalo.edu>
Sent: Friday, September 01, 2006 1:40 PM
Subject: Re: [Phys-l] gasoline

but ....?

I don't believe Sheron -- unless all his driving is highway below 65 mph

Our average is 42 and that's w/ ~ 1/2 freeway. Once I drove very
carefully 40 miles all but about 5 miles highway one and got 59 (</= 65).

bc, w/ over inflated tyres too!

Rick Tarara wrote:

The gasohol at 10% should not be responsible for the large mileage drop.
While the ethanol does have a lower energy content (70-80% of gasoline as I
remember), it is only 10% of the mixture. The actual drop in energy content
is only about 2% and that drop is compensated by the lower cost of the
fuel--supposedly! Now with E85 (85% ethanol) you would expect a 15-20% drop
in mileage, so E85 (requires special engines) needs to be considerably
cheaper than gasoline to be worthwhile. Then there is the whole debate
about the energy needed to produce the fuel. For gasoline, the NET output
is about 80% but for ethanol the numbers go from 40% down to negative
depending on who you listen to. 25% seems to be the number the government
is going with, but that ultimately means that the useful energy density of
ethanol is too low (read that as excessive land use) to be practical as a
real energy resource. As a way to reduce dependency on foreign oil or to
subsidize farmers, it may work just fine, but we are are really can't afford
the farm land needed to replace our gasoline use with ethanol use.

(I think the 45 mpg for a Prius is pretty much the norm.)

Rick (whose '06 gasoline powered Civic does get 40 mpg for 60 mph highway
travel, but

***************************
Richard W. Tarara
Professor of Physics
Saint Mary's College
Notre Dame, IN
rtarara@saintmarys.edu
******************************
Free Physics Software
PC & Mac
www.saintmarys.edu/~rtarara/software.html
*******************************
----- Original Message ----- From: "Sheron Snyder" <snyders@cablespeed.com>
To: "Forum for Physics Educators" <phys-l@carnot.physics.buffalo.edu>
Sent: Friday, September 01, 2006 11:01 AM
Subject: Re: [Phys-l] gasoline

Re: the Insight's 70 MPG report

Is that miles per gallon for the fuel we can purchase today?

I know the quoted mpg in the past was for gasoline not the gasohol (10%
ethanol) which is pumped today.
The gas stations are not required to tell us the mixture, so the figures
quoted may not be actual experience.

We own a Prius. We watch the mpgs very closely. The PRE- gasohol mpgs in
the summer was 62 mpg, Now we are experiencing 45 to 47 mpg.

This driving is done over the same course with the same driver and the
same
passengers and the same tire inflation and the car is regularly serviced.

Thought some would like the data.

Sheron
LCC Integrated Sciences

----- Original Message ----- From: "Rick Tarara" <rtarara@saintmarys.edu>
To: "Forum for Physics Educators" <phys-l@carnot.physics.buffalo.edu>
Sent: Friday, September 01, 2006 7:55 AM
Subject: Re: [Phys-l] gasoline

----- Original Message ----- From: "Brian Whatcott" <betwys1@sbcglobal.net>

In the September 2006 issue of Popular Science, there is an interesting
article on starting on page 50: "The Race To 100 MPG." A prize of \$25
million will be given to the first group to bring a 100-mpg car to
market.
And the race is on! >

In annual fuel economy competitions, vehicles which might loosely be
called cars make fuel economies in the thousands of MPG on a
flat track, using any and every fuel reduction technique known.

Which is why the competition is 'to bring a 100-mpg car to market.' I am
assuming the vehicle has to carry at least 2 people (4 would be more
useful)
and of course has to meet all safety regulations. That makes a big
difference between the somewhat meaningless fuel economy competitions
that
Brian notes, and something useful for the driving public. The Honda
Insight
nominally gets 70 mpg, so it would seem that the goal is not out of
reach,
but then again you don't see many Insights driving around -- can be a
scary
sight to see one surrounded by H2 Hummers! ;-)

Rick

***************************
Richard W. Tarara
Professor of Physics
Saint Mary's College
Notre Dame, IN
rtarara@saintmarys.edu
******************************
Free Physics Software
PC & Mac
www.saintmarys.edu/~rtarara/software.html
*******************************

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l