We're not getting 99.9 mpg ! Just sayin... :) !

Ok, hear me out...

(Caution: unnessary, academic, or fun exercise ahead - feel free to bail out if you are not a total math person, ultra-realist/literalist, or grammarian..)

Soo..., FWIW,
We don't really ever get 99.9 mpg.

I see people saying this on PC.com...and yeah, that's fun to say. I say it too..
It's a very cool feel-good statement.
I like saying it myself, when people are in the car and I want to use a handy way to demonstrate the prius concept --hey, look i'm getting 99.9 mpg down this hill.. Pretty cool! Love it.

But actually, there are more than one way to look at it.

Here are a few choices:

1. The dashboard says I'm getting 99.9 mpg.
yeah, whatever ! read on.

OR:

2. In that exact moment, I'm getting 'infinite' miles per gallon. or..umm.. 1 mile per 0 gallons.

i.e. for demonstration purposes:
If I go down a 1 mile hill in neutral:

I'm getting 1 mile per 0 gallons.

Which means: 1/0 = infinite miles per gallon.

Or, as I'd rather say in the real world:

1 mile per 0 gallons.


3. If I look at the 'trip', it could be 100 miles per gallon

On a two mile trip,
if the first mile was 50 mpg,
then that long down hill,
that's 2 miles traveled, using 1/50th of a gallon (during the first mile)
doing the math that's....
100 miles per gallon.

Or, if you don't manage things tightly, maybe 45 mpg for the first mile?
That's:
90 mpg.

Still not 99.9 mpg..

4. Or, using something more akin to apples to apples...like, an energy flow diagram or something:

If I'm on a flat section
And accelerate and then go into neutral..

or climb a hill, neutral it down and coast on the flat other side

Whatever those are I'll guess it averages to 40-60 mpg, since that's the average for most prii..

I'll say...50 mpg (of course!) lol


ok, that's all I've got.


So..

Besides the mpg gauge on the dashboard, I've got:

- 1 mile per 0 gallons
- Infinite miles per gallon (lol)
- 100 miles per gallon,
- 90 miles per gallon
and
- the keeper, 50 mpg.

None of those are 99.9 mpg!

 

We have a winnah !!

Oh..umm..yes. you are correct.