You ought to find local lab with one of these:

http://www.parrinst.com/default.cfm?page_id=174

DAS

 

Good idea. I sent them an e-mail asking if they can recommend someone.

I then used Google and found at least two US labs that appear to offer this service. I've sent them e-mail inquiries. This can give us a short 'test list' if it is affordable.

Bob Wilson

 

When I was a Management student at U of M, we did a lot of "real business case studies", among other things, there were several gas station/company examples. One in particular was about how the companies share their distribution methods. That is, Amaco gas may fill up a Shell station, while Marathon gas may fill up an Amaco station, and so forth. They do this to save costs on delivering the fuel to the stations, and since they all have to meet the same US fuel grades, they work out deals to make sure they're all even to their accountants. So, the fuel you get may not be the same, even if you fill up at only one station for years.

That would definately make things more fun in trying to determine if a particular stations gas delivers better MPGs.

 

Hi Ray,

I just joined this forum tonight and read your thread with great interest. I bought a new '07 in January and I have 4K on it now. I decided I would train it to like the cheapest crap gasoline I could find. My 1st tank was around 37.5 mpg. I used Arco and some non-major brand gas and finally pushed tyhe mpg up to 41-ish, but I couldn't get above that.

My last 2 tanks were Mobile and the mpg was slipping, 40 mpg, then 39 mpg. My driving is fairly consistent, as I mostly use it for commuting during the week over the same 60-mile course (30 miles each way).

Coincidently, about a week ago, I filled up with Shell. After about 20 miles, I noticed the mpg rising. I'm about 150 miles into the tank and I'm averaging 46+ mpg! Each day I commute, it gets noticeably better mpg.

I'm in southern California, so weather isn't much of a factor. Anyway, I just thought I should let you know you're not crazy and I don't think you're an agent for Shell --- just a nice guy sharing good information --- even if it isn't a full blown scientific study. I'm attempting to do the same thing, but I'm not sure why. I'd hate to see everyone suddenly buying Shell and bringing it to Shell's attention that their gas gives the best mileage. Once the secret's out, they'll boost their prices. So let's just quietly close this thread and keep ourselves happy.

 

PROGRESS REPORT:

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

COSTCO

• 'low fuel warning' - 136.4 miles @56.0 MPG, four days, city
• last tank to dry - 598.7 miles

SHELL

• 'low fuel warning' - 75.7 miles @56.1 MPG, two days, city
• 5 gallons to dry - 266.4 miles
• display codes cleared while adding one gallon, no need to manually clear the codes

CONOCO

• 'low fuel warning' - 81.0 miles @58.4 MPG, two days, city
• 5 gallons to dry - 259.7 miles
• call display codes cleared by themselves, no problem

BP

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.

Tonight, 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, I should take about a week per brand.

Questions? Concerns? Comments?

Bob Wilson

 

bwilson4web — My only comment would be that there's a possibility that the additives that Shell (and other "Top Tier" gasoline manufacturers) are touting for cleaning the fuel injectors and intake valves might be the reason for any FE improvement. If so, then it might take more than just 5 gallons of the new gasoline to show the improvement, and similarly, quite a while before any fouling from going back to another gasoline would have reached the stage of reducing FE again. Your test should, however, show whether the performances of the gasolines are significantly different, provided that any fouling-related changes aren't affecting the results. You should have a better idea about any such effects after a few weeks of experiments.

Stan

 

136 miles after low fuel warning? Wow... . Is that low fuel warning when it begins blinking the last notch on the meter? If so that means I could pretty much make it to San Diego on a blinking notch... .

 

IMO shell is pupular in asia there is possibilities they use shell to test the prius and calibrate it.

 

I would recommend getting a one gallon fuel can you can keep in the back. Having a 50 mile range after running out gives a lot of options.

Bob Wilson

 

Hi folks,

I had some handy data from September 2006 using Costco gas that I could use for a preliminary comparison with my April 2007 Shell gas test. That was a different grade of oil, 0W-30 versus current 0W-20, and about 20F warmer. However, I wanted to get a rough idea of what we're likely to see:


This is not definitive data and likely to change when I repeat the Costco gas test. However, it is enough to show there is some, detectable difference. But I can't tell if it is oil grade or winter/summer blend or temperature, ~60F Shell and ~80F Costco.

Bob Wilson