Situation No. 1
You really do not like to haul your grain too far, but you need to make some room in your on-farm storage for the new harvest, and the price you can get for your old crop is 10 cents higher about 100 miles away. You push the pencil, and it would be profitable to put some wheels under it.
On your third trip from the elevator back to the farm, you get detoured. There was an accident that closed the two-lane road. Being low on fuel, you stop at an unfamiliar small truck stop to fill the saddle tanks. They only have B-20, and you fill up and hit the road.
All is well until the next day when you are about one-quarter of the way into the second fuel tank, and the engine starts to act up. "Oh no," you say to yourself, "a tow home or road call will eat up all the extra profit made by selling to this elevator."
The truck manages to limp home, barely. The next morning after sleeping on it, you decide to pull the fuel filter and water separator. The fuel filter is plugged with sludge. In the shop, there was an extra filter, so you change it, and the engine runs fine.
You resume hauling grain but are worried about a repeat of the event. At the elevator, you bring it up to a couple of guys, and this is their opinion:
- Farmer A knows the truck stop and says the tanks are less than 6 months old, so they must have got a load of dirty fuel.
- Farmer B told you the B-20 has a cleaning effect and loosened up all the sludge in your saddle tanks and put it into the filter.
- Farmer C just said he does not know what happened, but you should never use B-20 unless the truck maker says so.
- Farmer D has no idea, but chimes in that is why he never hauls grain too far.
Situation No. 2
You know many vehicles over the past number of years say flex fuel on them and can use higher-ethanol-content gasoline. You do not understand what that means beyond the obvious.
Since you sell some of your corn to an ethanol plant, you feel it is time to learn about flex-fuel engines. You ask some of your friends, and they each have an opinion. Which farmer is the most correct?
- Farmer A says with a flex-fuel system, you can use gasoline with ethanol content up to E-85. He says it is accomplished by using special head gaskets in the engine.
- Farmer B agrees with Farmer A regarding E-85 but says it is not the head gaskets, but unique fuel lines along with a sensor to determine the ethanol content in the gas.
- Farmer C agrees with Farmer B but says there is more to it than fuel lines and a sensor. The engine control computer needs to alter the injector pulse width (opening) along with the ignition timing to accommodate higher proportions of ethanol.
- Farmer D says he does not give a hoot! In the late 1970s, he put gasohol in his VW Bug and burned up the engine.
Answers
Situation No.1: Farmer B is the most correct. I say this because any blend of biodiesel has a cleansing effect and will loosen deposits in the tank and the complete fuel system. Though some of the sludge may have come from the truck stop tank, the fact that they are new would mean the tanks did not have a high level of deposits. The grain truck is older, so it has the natural formation of sludge in the saddle tanks if the farmer used untreated fuel. That is why it took a day or so for the filter to plug.
Situation No. 2: Farmer C is correct. A flex-fuel engine needs to compensate for the lower energy density and different flame speed with ethanol. The same engine in non-flex-fuel form may have different fuel lines, larger injectors, a means to determine the ethanol content of the fuel and a unique calibration in the engine controller. The fuel delivery and ignition timing are different for high levels of ethanol in gasoline.
