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Old 06-17-2008, 10:55 PM   #10 (permalink)
ConnClark
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Join Date: Jun 2008
Location: Richland,WA
Posts: 967

Das Schlepper Frog - '85 Mercedes Benz 300SD
90 day: 23.23 mpg (US)

Gentoo320 - '04 Mercedes C320 4Matic
90 day: 22.44 mpg (US)
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Quote:
Originally Posted by gteclass View Post
This is typical naysayer logic... The percentage of the additive is not what is important, it is the vapor pressure and surface tension of the mixture of gasoline and acetone that gives the boost in efficiency. The drop below the baseline was probably because it takes a full tank on most cars for the computer to adjust the fuel trims for new gas. This is also why most people get best mileage out of the gas station they always go to. Not because the gas is necessarily better, but because the car is used to that particular gas.
ummmm... gasoline has a surface tension of about 21 ergs/cm^2 and acetone has a surface tension of about 23.7 ergs/cm^2 . If you could please post a link to some scientific produced table of the surface tension of acetone and gasoline solutions please feel free to do so.

By claiming that acetone lowers the surface tension I assume you are trying to say that acetone makes the fuel atomize more completely and thus burn more completely? Seeing that most cars burn 98% of their fuel how does burning 2% more fuel translate into into a 4mpg boost unless your car gets 200 mpg? It can't cause the fuel to burn faster because you would end up with a knock and that would cause shock waves to bounce around in the combustion chamber scrubbing heat from the gases to the walls lowering efficiency. What exact mechanism causes this claimed boost in efficiency?

Car computers adjust a cars operating parameters fairly quickly. Want proof? Try changing out a faulty O2 sensor. It doesn't take a full tank of gas for the computer to adjust to this. The car runs better immediately.

Lets say that it does take a full tank of gas for a car's computer to adjust things. That would mean that trikkonceptz alternating tanks of acetone laced and pure gas would be a total wash.

Quote:
Really bad advice, topping off a tank in this way is extremely bad for your evap system. Please just fill up until it clicks once. If you record your mileage at every fill up and the ammount of gallons it took to get there the resulting average fuel economy will be accurate. Each individual mileage reading between fill ups will vary no matter what you do, but the average of your readings will be accurate when you look at a few fillups.
I agree that there is truth to this statement. However in trikkonceptz's tests he was doing one tank with acetone laced fuel and the next tank without. There is no way to get a running average when testing in this matter. The only way to get an accurate reading is to drain the tank completely and then refill it or top the tank completely off with the former method being better than the latter.

Quote:
For one thing, maybe his wife does drive around with her foot in it. And are you going by the old epa estimates for your car or the new ones. Not to mention, 80s cars are MORE efficient than todays pieces of junk. Trust me also, getting 5% better mileage on a V8 truck with todays emmissions and safety standards without any hypermiling techniques is a serious gain.
In my mileage log calculation I use the new epa estimates however I just fixed the front suspension and had an alignment. I will also have new tires before I top off next and the last tank was about 80% city driving. The old epa estimate for my car is 22mpg the current one is 19mpg.

but lets see how my car stacks up to a new one.

1985 Mercedes 300SD California emissions
3.0L turbo diesel
118 hp @ 4,350 rpm
177 lb-ft @ 2,400 rpm
new epa estimate 19mpg city 20mpg hwy 19 combined
http://www.fueleconomy.gov/feg/2008c...olumn=1&id=339

2008 Mercedes Benz E320 Bluetech
3.0L turbo diesel
210hp @ 3,800 rpm
400 lb-ft @ 1,600 - 2,400 rpm
23mpg city 32mpg hwy 26 combined

http://www.fueleconomy.gov/feg/2008s...E320%20Bluetec

I think new cars are more powerful and more efficient despite tougher emissions controls and more restrictive emissions devices. They are cleaner too
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