E85 is a poor financial decision, period. E85 saves you about 10% per gallon, but the energy content is about 25% less than E10. So while the cost per gallon is less, the cost per mile (or per hour) is about 12% higher.
Oil and water don’t mix, but ethanol and water do mix which is why ethanol sitting in an unused engine can cause rust to form if there is any water dissolved in the ethanol.
nd_n8, I think it’s likely that E85 would make the problems you described worse, not better. It has a deteriorating effect on rubber fuel lines and it attracts water. If you’re leaving a mower out thin the weather, E85 is not a good idea there at all. You asked what modifications would be needed. At a minimum, I’d replace the rubber fuel line with steel, and advance the timing a little.
You do have a point about the huge quantities of gasoline being burned by all the lawn equipment out there. Certainly one could argue that it’s unnecessary. But, worse than the mere quantity of fuel, it’s the way that the fuel is delivered and burned. Compared to automobile fuel, a much larger fraction of lawnmower fuel gets spilled on the ground. Personally, I can’t remember EVER successfully putting fuel into a gas mower without spilling at least some of the fuel. And I challenge anyone to take an empty gas can to the station, fill it up, and bring it home and store it in the garage, without spilling any of it or letting the fumes escape. And then there’s the fact that lawn equipment doesn’t burn gas as cleanly as cars do. If lawnmowers had to pass the same emissions tests that cars do, they’d fail miserably. And don’t get me started on two-stroke engines.
Some people will argue that E85 itself is a bad idea. I disagree with that assessment. But even if you’re convinced that it makes sense to replace fossil fuels with renewables, I’m afraid that this small improvement still wouldn’t make up for the emissions problem.
That’s why I switched to an electric lawnmower, one with an 80-foot extension cord, no battery. It never spills any fuel onto the ground. And, here in Oregon, over half of its power comes from renewable sources. I’m also looking for ways to reduce the amount of my yard which requires mowing. Some of my neighbors have planted their yards with shrubs in such a way that there is nothing left to mow.
This also applies to marine engines, classic cars, and anything else that doesn’t consume fuel on a regular basis. When the ethanol in the fuel mixes with humidity in the atmosphere, over time it creates stale acidic garbage that will chew up aluminum and other parts in your engine.
Ethanol fuel (E10, E15, E85) was created by the mid western corn growing states through powerful lobbying. It has nothing to do with making us energy independent as it takes more energy to produce it than it gives off.
You may be able to find a gas station near you that sells pure gasoline by going here: www.pure-gas.org It’s worth the extra money to keep your lawn equipment in tip top shape.