Gas experiment

[bwilson4web]

Hi folks,

PROGRESS REPORT:

Have you ever tried to run a Prius dry? I have and the first time, it is not fun:

* 'low fuel warning' - ran 136.4 miles @56.0 MPG, four days, city, from flashing start to end
* last tank to dry - 598.7 miles

Do not try this unless you have a way to clear your engine and hybrid ECU error codes. When I finally ran out of gas, my speed dropped below 42 mph but I still had electric mode. I simply drove a couple of hundred yards to pull into a parking lot. I have no interest in measuring traction battery range since I don't have a 'spare' traction battery or portable traction battery charger.

I reset the engine and hybrid ECU codes and then put one gallon of Shell 87, bought in Huntsville AL, into the tank. The car started instantly and I drove directly to the Shell station and added four gallons. The fuel indicator came up to four bars. I then refilled the one gallon can with Texico 87 octane.

Soon I'll do a Brindley Mountain 'hill climb' test at 55 mph and compare the results to the earlier 'low-cost gas' data. At this rate, it should take about a week per brand.

Bob Wilson
03 Prius, NHW11

SHELL:
5 gallons -> 266.4 miles
'flashing low gas' to 'engine quit no gas' -> 75.7 miles @56.1
did not need to clear codes as the other errors went away after adding one gallon. Only 'flashing' remained.

CONOCO:

[tripp]

Bob, you so crazy! Good stuff. I'm interested to see what you find out.

[hobbit]

Do you think you could have restarted after putting your gallon in
but *without* clearing the codes? I'm still trying to get the real
story [for both NHW11 and NHW20] on whether a few reboots will clear
that condition, or if someone really needs to take a scantool to it.
.
_H*

[bestmapman]

How many miles did you travel after the last pip started to flash?

[bwilson4web]

This is preliminary data using some Costco gas, mountain climbing data from September of last year. This is not a definitive report but just PRELIMINARY data:


Differences included: (1) 5W-30 (Costco) vs 0W-20 (Shell), (2) 80F (Costco) vs 60F (Shell). I'll have to repeat the Costco gas test.

Bob Wilson

[bwilson4web]

<div class='quotetop'>QUOTE(hobbit @ Apr 13 2007, 05:26 PM) [snapback]422997[/snapback]</div>

Do you think you could have restarted after putting your gallon in
but *without* clearing the codes? I'm still trying to get the real
story [for both NHW11 and NHW20] on whether a few reboots will clear
that condition, or if someone really needs to take a scantool to it.
[/b]

I'll do it on at the end of this tank. I'll add the extra gallon and then try three restarts. If that clears the indicators and everything else works fine, we'll be good to go. If not, I can clear the remaining code(s).

Bob Wilson

[hill]

You could have read a few other thread on P.C. & save your self a lot of grief. The search tool is a wonderful thing. And my favorite Cliche of all time: Historians say that the only thing folks ever learn from history is that folks NEVER learn anything from history.


But I try to learn.

[bwilson4web]

<div class='quotetop'>QUOTE(hill @ Apr 14 2007, 06:13 PM) [snapback]423387[/snapback]</div>

You could have read a few other thread on P.C. & save your self a lot of grief. The search tool is a wonderful thing. And my favorite Cliche of all time: Historians say that the only thing folks ever learn from history is that folks NEVER learn anything from history.
But I try to learn.
[/b]

The only grief was trying to make sense of both the search results before and after this experiment started. There are a lot of testimonials without evidence of a well defined methodology. Now if you have a particular URL or search term that provides either a table of brands and their energy content or a graph of brands and energy content, please post it.

In the meanwhile, I'll continue my survey of Huntsville AL gasoline brands. The methodology is straight forward and I enjoy answering question and addressing concerns. Once I've mapped the gasoline energy range, I'll send samples from the highest and lowest gasolines to a lab. This will quantify my results and support an accurate calculation of engine efficiency. It will also let me calculate the cost/mile of the different brands.

Bob Wilson