Potential Parking by the Numbers

[PaleMelanesian]

Some coworkers asked me about Potential Parking, so I did some testing and calculating.

The parking lot at work slopes up from the building about 250 ft, with about a 20 ft rise over that distance. I've been parking at the extreme far uphill end, and they noticed me walking all the way out there. The exit I use is there at the top.


Comparing that to circling the lot until I've lost all momentum, and creeping into a space right in front of the building:

8.7 miles - the route I drove that day.
65 mpg - an average daily commute on that route.

400 ft - Extra distance if I loop the parking lot and park at the bottom.
250 ft - Extra distance to climb back to the top of the lot.

20 mpg - climb from the bottom to the top of the parking lot. (250 ft)
infinite mpg - looping the parking lot to park at the bottom. (400 ft)

65 mpg / 17.4 miles - Daily round trip if I park at the top.
64.86 mpg / 17.53 mi - Daily round trip if I park at the bottom.

.2677 gal - fuel used if I park at the top.
.2698 gal - fuel used if I park at the bottom.

Potential Parking at the top saves 0.8% fuel for the day.
Parking at the top save 0.2% mpg for the day, but over 0.6% shorter distance, giving the same 0.8% difference.

[xcel]

Hi Andrew:

___Another Hypermiling metric locked down to the fractions of an ounce of fuel saved. Nice job

___Good Luck

___Wayne

[lnmcmahan]

Originally Posted by PaleMelanesian

Potential Parking at the top saves 0.8% fuel for the day.
Parking at the top save 0.2% mpg for the day, but over 0.6% shorter distance, giving the same 0.8% difference.

Statistically speaking:
This is what I would call statistically insignificant. repeat the experiment a couple hundred time, run a chi-squared distribution, and post again! :=-)

That said, I still believe your results would be borne out by the "hard evicence".

Larry

[VekTor]

From these numbers, should I conclude that you might actually lose out on the deal if you had to go the same distance extra to get to the potential point in your lot (lengthening total trip instead of shortening it)?

[xcel]

Hi VekTor:

___You adjust your entry speed so the potential you gain takes away from the kinetic you supplied earlier via the gasoline engine. Once you know your entry speeds, you will work it so that you are < 1 mph when you reach the most opportune (read maximum potential) parking spot while just breaching the crest so that you are facing downhill in a Face-Out.

___Good Luck

___Wayne

[bomber991]

PP: Potential Parking : When entering a parking lot of any description, seek out the highest spot in said parking area. What this encompasses is looking for the highest elevation (Potential) and usually FAS’ing to bleed off speed so you DWB into said spot. On egress, you have a downhill slope to help you accelerate in a Fas or with ICE-On thus increasing your overall average FE . Pros, decreased fuel consumption and usually easier egress as you are usually in the back of the mall, grocery store, whatever. Cons, usually farther from the store entrance and thus a longer walk.

Ok, I still don't quite understand the point of PP. It sounds like you FAS the car, and keep coasting until it stops, and then that's where you park.

But it seems like cheating to me. Myself I just park in the back so I don't have to waste time searching for parking spots, and also to avoid door dents.

Now the reason it seems like cheating, is that you're just rolling around the parking lot for no real reason in particular. I mean it's just adding extra distance on your odometer that's not really required. It increases your MPG but it would seem to me if you just hit the brakes and park somewhere quick instead that the fuel consumed would still be the same, and isn't that what matters the most?

[Right Lane Cruiser]

I think you missed it by a little. PP is the practice of putting your vehicle where it will have the most kinetic potential energy to help you get going later. This means avoiding the need to back out (low, inefficient gear and an extra stop) and finding high spots so that you can get some gravity assist. I like to park in such a manner that I can just let the car roll out of the slot unpowered. Failing that, I at least make sure I can just pull straight out.

Face out parking is also safer as you have a much better view of what is in the path of intended travel. You will never run over a child if you are pulling foward and attentive while it is very easy to not see a child when backing up (due to poor visibility).

[ATL]

Originally Posted by Right Lane Cruiser

You will never run over a child if you are pulling foward and attentive while it is very easy to not see a child when backing up (due to poor visibility).

Sean, you sound like a dad

[Right Lane Cruiser]

Originally Posted by ATL

Sean, you sound like a dad

[PaleMelanesian]

In my case, PP means I park in the first spot as I come into the lot. Continuing across the parking lot is downhill. It boosts my numbers for the incoming trip, but I lose on the departure, more than what I gain coming in.