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June 2002 Hydrogen-Boost Newsletter

Saturn SL1 Tests:  61.6 mpg, 27.6:1 air/fuel mix

    I have put over 4000 miles on my 1996 Saturn SL1, 5-speed since I bought it.  Usually when I purchase a vehicle I will do a baseline mileage test and immediately install the Hydrogen-Boost system.  Because of this I have been unable to test new devices on the market that may influence mileage.  This time I decided to add the other devices first and install the Hydrogen-Boost last. 
    My baseline test drive was a trip from Boston, where I purchased the vehicle, to Glens Falls, New York, a 240 mile drive.  I tested at 70 mile per hour cruise and achieved 40 mpg stock.  This compared exactly to the EPA published highway mileage figure so I used the EPA published city mileage figure for my city baseline. 
    My first modifications were to install a Condensator and a Power Cube obtained from Bruce McBurney.  My next test drive was a trip to Plattsburgh, NY at 70 mph cruise on which I also got the same 40 mpg.  On my return trip I traveled at 55 mpg cruise and achieved 47 mpg.  I concluded that improvements were achieved by either device, but for protection of the engine I left the Condensator installed. 
Since the Power Cube was not designed for increased mileage but for increased power I tested it for power.  With the Power Cube disconnected by removing the fuse, I ran eight acceleration tests from 20 to 60 mph in 5th gear, and eight acceleration tests from 10 to 40 mpg in 2nd gear.  After throwing out the fastest and slowest times for each scenario I averaged the remaining times and got something like the following: 21.6 seconds for 20-60, and 8.6 for 10-40mph.  Then replaced the fuse to the Power Cube and repeated the acceleration tests.  My averages were within .04 seconds of the baseline tests so I concluded that no increase in power was caused by the Power Cube. 
    Next I installed a Trasko spin on “by-pass” oil filter and 0w30 synthetic oil, and pumped up the tires to 50 psi.  Very little change in fuel mileage was noticed.  Adding the XCEL Plus engine treatment also cause little increase in mileage. 
    Then I installed the Fuel Enhancer sold by Trasko and found absolutely no increase in mileage as expected.
    Then I added the fuel heater I sell for the Hydrogen-Boost system and achieved 50 mpg at 55 mph highway.  I also achieved 50 mpg in the city by applying all the driving techniques in the Hydrogen-Boost manual except shutting down the engine during coasting. 
    After three tanks full I decided to finally add the hydrogen generator and go for a real improvement test.  You have to remember that with a fuel heater on an EFI equipped vehicle with a return fuel line, the fuel in the tank gets warm and causes thermal expansion.  I noticed this on all of my previous test vehicles.  Usually the thermal expansion, on a short (43 miles) test drive, would cause a .2 to .3 gallon discrepancy in the amount of fuel used, if I started with a cold tank full and ended with a warm tank full.  This discrepancy could be countered by filling when the tank was warm and almost full and do repeated tests, filling after each 43 mile test.  Also I could start with a cold tank and let the tank cool overnight before refilling to counter the need for adjustment, however care would have to be taken to insure that the outside air temperature at the time of the original filling for the test was the same as the temperature the next day when the tank was refilled.  Sometimes I had to refill on a cold morning, which caused a need for a thermal contraction adjustment.   Only when the test was done with a cold tank and ended with a warm tank did I have to make a substantial adjustment for thermal expansion of the fuel.
    After installing the Hydrogen-Boost gas generator I did a few tests and achieved a best result of 57.5 mpg at 55 mph cruise, and 50 mpg at 70 mph cruise.  I installed and properly adjusted an EFIE (electronic fuel injection enhancer) from Eagle Research, a vacuum gage, and my water mist system and did another test at 55 mph cruise, achieving 61.6 mpg.  During the last two test drives I noted the vacuum setting at each steady cruising speed and used these for some calculations. 
    Noting that on the test drive the intake vacuum hovered around 16 inches of mercury (standard pressure is about 30 inches), and the tachometer read about 1920 RPM, I used the following calculations to figure the air to fuel ratio during the test drive:

1 gallon X .9167 mi X 4 quarts X 1 liter     X 760 grams = 41.1 grams fuel per minute
61.6 mi      I minute     1 gallon   1.1 quarts    1 liter

1920 rev X 14” Hg intake pressure  X  2 liter displacement = 896 liters air per minute
1 minute     30” Hg standard pressure   2 revs/intake stroke    

Then we can make a small adjustment to the total volume of the air to adjust for the portion of the fuel that evaporates in the intake, which contributes to the manifold absolute pressure.  Assuming that 1/4 of the fuel evaporated in the intake we calculate:

41.1g X 1 X 1 liter(density of evaporated fuel) = 1.713 liters evap. fuel in the intake/min
fuel        4     6 grams

subtracting 896-1.713= 894.287 liters STP air
multiplying by the density of air 1.27 g/liter X 894.287 liters = 1135.7 grams air/minute

dividing the air per minute by the fuel per minute 1135.7/41.1 = 27.6 to 1 air to fuel ratio

    This air/fuel mixture seemed quite lean to me and I hesitated to even report it, but then I checked the files at the supercarbs egroup at Yahoo, and found that for gasoline the best stochiometric ratio was 1.76% which translates to a 56.8 to 1 ratio.  So even though the normal air/fuel ration for an EFI equipped vehicle is 14.5 to 1, a 27.6 to 1 is not really impossible.  However comparing the 27.6/1 ratio with the perfect case 56.8/1 ratio reported in the files at supercarbs, it is obvious that there is still much room for improvement before we get our engines to be totally efficient.  Comparing these ratios leads me to believe that the mileage of the Saturn could be increased to over 100 mpg under perfect conditions and modifications
I will have to admit that the mixture during my test drive was leaner than what most people would call comfortable, because a slight to moderate depression of the accelerator would cause a hesitation of the smooth acceleration of the vehicle.  But when real acceleration was needed I could depress the accelerator further and the ECU would kick into default mode, giving me all the smooth acceleration I needed, of course at the expense of fuel mileage.  I will likely not run the mixture quite so lean because this is an aluminum engine and I don’t know how it might affect the valve seats. 
Note:  Further examination of the above calculations of air/fuel ratio reveals a flaw in the logic of the calculations.  Though the vacuum reading of the vacuum gauge attached to the intake manifold was relatively accurate, it does not give us an accurate measurement of the vacuum or absolute pressure in the combustion chamber at the bottom of the intake stroke.  Since the piston is sucking the low pressure intake air into the cylinder, the actual absolute pressure in the cylinder would be somewhat lower that the calculations reveal.  Therefore, the actual air/fuel ratio is likely somewhat lower than the 27.6/1 that the calculations bore. 

Conclusions:  The following devices made no difference in fuel mileage:
    Power Cube (not advertised to improve mileage)
    Condensator (likely to improve mileage on older or worn out vehicles)
    Trasko Enhancer (not likely to improve mileage on any vehicle)
    Trasko Filter (not advertised to improve mileage)
The following components made a minor improvement in fuel mileage.
    XCEL PLUS engine treatment
    0W30 Synthetic Motor Oil
    50 psi air pressure in the tires
The following components in conjunction made major improvements in fuel mileage
    Fuel heater
    Hydrogen-Boost hydrogen gas generator
    EFIE device from Eagle Research
    Water Mist system
The following component was not installed
    0W30 motor oil in the manual transmission (the Saturn comes with light weight automatic transmission fluid in the manual transmission)

Improvements achieved over EPA reported mileage/baseline tested mileage:
    Highway (70 mph):  50 mpg, 25% improvement before EFIE and water mist
    Highway (55 mph)  61.6 mpg, 54% improvement
    City  50 mpg, 72.4% improvement before EFIE and water mist

I expect that further tests with the EFIE and water mist will achieve 55mpg at 70 mph, and 55 mpg in the city.  This would represent a 37.5% increase at 70 mph and a 90% increase in the city.  When full implementation of the driving tips in the Hydrogen-Boost operator’s manual are used in the city (including shutting off the engine during coasting) I expect to achieve at least 61.5 mpg for a 112% increase over the EPA reported city mileage figure.  The reported and expected results are consistent with every other vehicle I have tested with the Hydrogen-Boost system except the automatic transmission equipped Dodge Dakota, which was sold before development of the full system.  A later longer test drive (250 miles) on the hilly back roads of New York and Vermont yielded an average mileage of 55.0 mpg. 

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