<VV> MPG Hystery

[Bruce Schug]

On Aug 24, 2005, at 8:53 AM, <tkalp at cox.net> wrote:

> Ron,
>
> I am guessing you never have participated in a Corvair Econorun.  The 
> difference isn't the evil, cheating Corvair drivers . . . the rules 
> are quite different.  I navigated for the winning car at the Iowa Mini 
> Econorun 42.9 mpg out of a 61 80 hp PG sedan . . . and we didn't use 
> every opportunity to save gas.
>
> A major factor was that we left topped off to the top of the filler 
> neck.  When we finished the officials filled the car until the pump 
> clicked off, which gave us an extra pint of gas.

*SNIP*

It pains me to hear that this was done at a convention economy run. 
This is not an acceptable way to fill the tank at an economy run. I 
have no confidence that every pump will shut off at the same point in 
every fuel filler neck. Some tanks have kinks in return hoses or other 
strange things going on with them. I just don't believe this will work. 
The CORSA Economy Run rules read as follows:

3.8(ref. 2.6) The following techniques shall be employed to ensure 
accuracy of results:
(a) All competitors shall have the same start point and the same finish 
point.
(b) All competitors shall start with a full tank of gas.
(c) The gas tank shall be filled to the same level on all vehicles at 
the end of the economy run. To ensure a consistent fill-up level for 
each car, the following procedure/conditions shall be followed for each 
class: • The same person, only, shall top off all gas tanks to the same 
point. • One gasoline pump, only, shall be used. • Each vehicle shall 
be stopped at the same location. • Each vehicle shall be filled from 
the same side of the gas pump. • Nobody shall be allowed in the vehicle 
during fill-up. • The quantity of gasoline used to fill a competitor’s 
tank shall be recorded. • Because of the different grades of gas 
required by Corvairs, it is highly recommended that premium gasoline be 
used to fill all vehicles.
(d) The most accurate method of measuring gas consumption shall be used 
during fill up. Depending on the style of pump, this could be “gallons” 
directly in the case of the newer digital pumps, or “cost” in the case 
of the older, analog pumps which is then converted to gallons based on 
posted cost per gallon.
(e) Because of the difficulty in reading some LCD pump digits in 
sunlight, care should be taken as to the best side of the pump to use 
if recording of gas used is done by observation rather than printed 
output.

I'm sorry to hear that these rules have been interpreted as allowing 
the automatic shut off to determine when the tank is full. That was not 
the intent of the rules.

The proper way to fill the tank is for one person - the same person - 
to fill all of the tanks of all the vehicles in the same class. This 
person is assisted by another person. The "filler" carefully inserts 
the fuel nozzle into the filler neck and begins filling slowly, to be 
sure all the air escapes without causing a "burp". The assistant tells 
the filler when he may be getting near full - actually when the fuel 
may be starting to come up the filler neck - based on how much fuel has 
been pumped into the tank. All this time the filler must be working in 
the shade with a good flashlight so he can see the fuel level when it 
comes up the filler neck. If there is too much light, the filler should 
have a piece of cardboard or a hood or something to shade his view 
(held by the assistant). He should be holding the fuel nozzle with one 
hand and the flashlight with the other, carefully watching the fuel 
level. Once he sees it coming up the filler neck, he goes very slowly, 
making sure all the air has escaped and the fuel level has settled. 
Finally, he chooses a point on the inside of the filler neck which he 
can clearly see. This point will be the same in all filler necks. I 
suggest the top of the neck, just before fuel starts to overflow. When 
the fuel lever reaches that point, he stops. The assistant records the 
quantity of fuel.

I know that sounds like a time consuming, painstaking way to do this, 
but it is the only way I've seen to get consistent, accurate fill ups. 
If you were in an economy run and this wasn't done, it was done wrong. 
If you ran an economy run and you didn't do it like this, you did it 
wrong. And if you used the automatic shut off - SHAME ON YOU!!!

Our club has had an annual economy run for years. After a few, you 
learn what works and what doesn't. I suspect some putting on a 
convention have never put on an economy run before. This is too bad.

Finally, I can get upper 40's in about any economy run I enter. Not bad 
for a 2,760 pound 140 with a 280 cam. And I'll tell you, it's not done 
driving like you have an egg under the accelerator. If you think that 
is the way to optimize fuel economy, you should study some books on 
internal combustion engine theory.

Bruce

Bruce W. Schug
CORSA South Carolina
Greenville, SC
bwschug at charter.net

CORSA member since 1981

'67 Monza. "67AC140"