Lawn Mower Fuel Brand Experiment

[n0rt0npr0]

I located the CLOSEST Chevron! It's 165 miles away in Amsterdam, Ohio. I'm up for road trips but not the expense of that long a drive. Donations appreciated...lol, cuz I'm crazy enough to go get it:P

The nearest 76 is 63 miles away in Howell, Mi.

[krousdb]

Originally Posted by Compaq888

well this blows. Some of use can't really use this because we have different gas stations. I only use Chevron and shell because all the mechanics we've been to recommend it.

First things first. Lets prove that there is a statistically significant difference between several fuels. Then lets worry about testing the different brands. Since gasoline generally travels through a pipeline to get to different parts of the country, any difference would be in the additives that are mixed in at the terminals.

Another thing to consider.... Right about now, there is a change from the winter blend to the summer blend of fuel, 112,500 BTU to 114,500 BTU. You need to be sure that you are testing the same blends or your results will be inaccurate. There is also a change from MTBE to RFG? Lots of variables here with the boutique blends. Driving to another state to get a particular brand of fuel might result in a different blend. So in addition to testing Shell, BP, Chevron, etc, we also must state winter or summer blend, RFG, CBG, etc...

[krousdb]

Originally Posted by n0rt0npr0

Yes, gravity clears the whole fuel line and stalls the mower out for the next run. All the way down to the last drop of fuel.

And there were many constants during this round. I may have to get a normal measuring cup to truly measure 200ml out on a perfectly level surface, rather than this inverted cup to get any closer consistancy.

There are no leaks and with no wind this round, no measurable evaporation.

You might want to try one of those syrnge like things for measuring medicine for children. I have a 50ml one. Also, are you running at idle or low or high throttle?

[Compaq888]

krousdb is right you might be using winter bland for one gas and summer gas for another brand. You might want to wait a month till everybody uses summer gas.

[n0rt0npr0]

I did consider that but I doubt 2000 btu is statistically significant inside of a 200ml run.

Also, this area uses massive amounts of gasoline. Our public transportation system is one of the worst (smallest) in the country. We are slow to switch to the more expensive summer blend. They won't allow that to come around until May 1st. AND my impression from last year is right before labor day weekend will they release it to the stations. This can be proven upon request.

MTBE? They've talked about that here. Since the 80's there has not even been a chance of it here though. MTBE is an oxygenate as is ethanol, current states with cities using an oxygenate are: Texas, Colorado, Montana, Utah, Alaska, Oregon, California, Nevada, Arizona, Minnesota and Washington. No RFG either here.

The mower is on "fixed" full/high throttle. I never move it, and its zip tied in place.

I aquired a 60ml syringe. Retesting using that for the sole measuring.

[krousdb]

I guess maybe Matt can tell us if 2000 BTU, approx 2% is statistically significant. I was thinking that if one brand consistantly showed a 2% increase in run time over the others that it would be significant. I am expecting no difference.

But it sounds like you have the winter blend so your results will be interesting. Are you retesting with 200 ml or with 60 ml? Good idea with the zip tie.

[n0rt0npr0]

Thanks for the syringe idea, I am testing now and have some very close times. I must be very very close to 200ml this time around.

Yes, staying with 200ml for all the runs. Thanks for the ziptie comment.

My last test will be over in 30 minutes(its 2:45 now), and five minutes later I will post the results.

[krousdb]

Originally Posted by n0rt0npr0

My last test will be over in 30 minutes(its 2:45 now), and five minutes later I will post the results.

The suspense is killing me! What brand is next?

[n0rt0npr0]

Okay first, Mobil is the fuel to be tested next.

Again, I took aproximately 15 minutes between runs to restart.

The constants in this round are:
-Three 200ml runs (warm runs)
-Barometric Pressure remained statisticly constant at 29.35in - 29.37in
-No measurable windspeed on first two runs, change listed on third
-Same Shell Gasoline as first run

Run #1
-Length: 22:00.00 minutes
-Temp remained within 46°F
-Humidity was 38%

Run #2
-Length: 22:17.00 minutes
-Temp remained within 46°F
-Humidity: 38%

Run #3
-Length: 21:49.00 minutes
-Temp remained within 47°F
-Humidity: 37%
-2.33mph average windspeed

[krousdb]

OK, but does 21.49 mean 21 minutes 49 seconds or 21.49 minutes?