Random Thought of the Day
 

While parking my car today in a big lot with several available spaces I had a random thought and wanted to see if it holds any water (even a smidgen of truth will convince me I haven't gone totally bonkers).

When driving in reverse (i.e. backing out of a parking space ordriveway) does the odometer actually run backwards and decrease in total mileage (even .001 of a mile when you backup)?

And if the odometer does run backwards would it be beneficial to MPG to always park so your car can pull forward out of a parking space rather than backing out of a parking space (even if it saves .001 of a mile when you pull forward out of the space)?

Alot of times in big parking lots you can pull into a space and go through that space into another space (allowing your car to pull out forward the next time you get in).

Obviously, I would not expect any substantial MPG savings if this is true but when random questions arise then random answers are needed.

Welcome to my brain after working an 18 hour shift! :eek:

The answer my Friend is
It depends.
I have not worked on a car, ever, that ran the Odo backward.
Newer cars, 1996 & up usually, the Odo runs forward all the time. Even when you back up.
Try backing down your street in the middle of the night sometime. You will see that the Speedo registers road speed and the Odo goes up .1 mile.
Older cars, cable and gear driven stuff, the Odo stops and the Speedo stop when you reverse.
No loss of miles but no gain either.
You are not crazy.
I am sure others were waiting for you to ask.
Schultz.

In any case, it wouldn't change your actual mpg at all, just add another bit of inaccuracy to the computation.

Regardless of what the odometer does, you'll find that "pull-through" parking (vs. reversing out) is recommended in the 100+ Hypermiling Tips .

Didn't anybody see Ferris Bueller's Day Off? :D

That's exactly what I was going to say!

I did see Ferris Bueller's Day Off, and unfortunately the movie is accurate, miles will not come off the od without you actually messing with the od and rolling it back yourself. Which is not recommended. But backing out of a parking spot is not recommended simply because you use more gas to back up and then drive forward than you would if you just pulled out of a spot.