6/04         GASOLINE VS. DIESEL

Your generator could be fueled by gasoline, propane, or natural gas, but it really should  be fueled by diesel. 

 

As a backup fuel 

GASOLINE:

  To any one that has cleaned a carburetor on an old tractor or mower that the fuel has gone rancid in.  They know the smell and residue left by old gasoline.  They also know that the engine won't run well if at at all on the bad fuel.  As a matter of fact that is why you have the carburetor in pieces on the wife's pizza pan.  One must look at some properties of gasoline and how it is made.  A gasoline engine does not burn liquid gas in the cylinder it burns gas in a gaseous state.  By the time the fuel gets to the cylinder it has vaporized.  So. Gasoline is designed to evaporate easily which does not lend it's self to long term  storage.   Gasoline is a complex mixture of many aromatic solvents like naphtha, benzene, and octane as well as very light hydrocarbon compounds. The molecular structure is highly engineered to burn stably under compression and not detonate.  In past years this was  accomplished with the use of methyl ethyl lead but with the removal of lead from gasoline  it must be done with a cocktail of synthetic additives. The decomposition of these  additives  and the  loss of the aromatics leads to a fuel that is less than desirable to store.  Two other reasons are that Gasoline manufactures  change formulas in moderate  climates from summer to winter fuel.  So if  you buy summer fuel that has less aromatics  and must use it in winter than the engine is not going to run properly. Likewise if you ran winter fuel  with lots of aromatics in summer the engine can vapor lock  or detonate. 

. Summer fuel has less aromatics and will not work well at 40' and below it won't evaporate.  Winter fuel has lot's of aromatics and in summer  can lead to vapor lock of fuel systems.  The last and final reason gasoline is not a good fuel to be stored is that it is VERY FLAMMABLE. It can be ignited with any spark. And it's evaporative properties make it's fumes  vary dangerous. fumes of gasoline are flammable and explosive if properly mixed with air.  There have been many fires and a explosions set off by pilot lights,  furnaces and light switches.   It has been said that under the right situation a gallon of gas has the explosive potential of 8 sticks of  dynamite.  Where's that can I keep for the lawn mower? 

 

DIESEL:

 Diesel fuel, or fuel oil or #2  is a direct result of petroleum distillation it comes off the cracking tower above the light oils and below the solvents. # 2 fuel oil is what we commonly call diesel.   It is slightly heavier than kerosene and jet fuel  yet lighter than vegetable oil. instead of octane rating which is a scale for gasoline for resistance to detonation. diesel has what is known as the c tane rating  which is a indication of it's ability to ignite in the cylinder under compression. Diesel because it is an oily fuel with no high solvents  to evaporate  is a very stable fuel.  Diesel can be stored for many years with little degradation. Diesel produces little in the way of fumes and is fairly safe around  small sources of ignition if stored and contained properly. As a fuel for back up power generation it is one of the best and because diesel engines by nature burn less fuel per hp. less will have to be stored incase of or  handled during a power outage.  On thing I must mention about diesel fuel is a microorganisms will live in diesel that is stored for more than a year but there are several products on the market one is called BIO-GUARD it will keep this at bay for years. Diesels are a little different than gas engines in that they have no sparkplug to foul. They have no Ignition to go bad or get wet.  That is why you see the Hummers that the army uses running almost all the way submerged in water.   As a matter of fact they put snorkels on the air intakes and they run with the engine completely submerged. Try this with you lawnmower or "small bloc Chevy".  I don't know  how many have cleaned your motor on your car  and had to work to get the engine running again because the ignition is wet. It is sort of a pain .

 

PROPANE/NAT. GAS

Propane has some high merit as a back up power generator fuel as it is contained in cylinders and tanks. if the container leaks the gas goes in to the atmosphere and not on the ground.  This would require cleanup and contact with the nice EPA  agents, fines and other niceties.  Propane have two draw backs they have less BTUs per pound than gasoline and more will be required than gasoline or diesel if a long duration is required.   Another problem with propane is that it is heaver than air. If it escapes from a tank or a pipe it can easily fill a basement or depression in the ground and be ignited by the smallest spark,

Natural gas:  Natural gas may  not work after an earth quake as supply lines mat  be disrupted or turned off till inspected. 

 

Consumer Generators:

     For short runs and RV ing consumer generators are fine.  As  a matter of fact I own a Honda 1000w  for short outages and charging my camper batt. I like it it is silent, light  and compact.

BUT what if there is a serious outage and you have to be a week or two with out power?  Will the Honda hold up or produce enough to pump your water? Mine Wont it does not have 220v.  How much gas do you normally keep? Is it still good and for the right season?  A week can be a long time without power.   

     What about off grid living with a consumer generator? Let's see  Aluminum pistons, aluminum cylinders , No replaceable  main bearings, no replaceable rod bearings. How long can this live?  and what do I do when it fails.  What it is designed to do, Throw it away and buy another  at a big flashy price.

 

What got me working on this subject 

I bought a portable welder with 20 kw  power on it.  It was great on the farm for repairs and such but the  day came when  we lost our power for the first time after a freak wind storm.  I was not sure I had to the answer to my problem.  It ran my lights, fridge, freezer, pump and pellet stoves but it burned  2 1/2 of gasoline per hour regardless of load.    2 1/2 .gal./hr =60gal/24 hrs  or at least 30 gal for 12 hr  or 15gal  for 6hr.   This is gasoline at $1.65 or $99.00 per day  I think you see my point. It got a little cold  between generator runs ( abut 4 hr per day to keep freezer and water going)

HOW MUCH  GAS DO YOU KEEP ON HAND ?? or do you want to go get? especially if the road may not be clear. 

Diesel engines by nature are more efficient than gas engines.  The fuel has more btu.s per lb  than gas.  This all spells better fuel economy.  On the lister type engines it has be said it will run on 1/8gal/kw/hr =5gal. at 8hrs with 5kw output.

 Now on that cold  dark and stormy night  when the lights go out and you grab a flash light and go out in the garage  and get out the generator that you used the last time the lights went out.  You unscrew the fuel cap and you smell that old familiar smell of bad gas. Enough said.  

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