I've a problem with this.This article
contains this statement.
"A gas mower creates as much pollution as running eight cars. We saved 22,000 car miles in pollution in our first year,"
Hmmm. If we figure 25MPG as average, that's 880 gallons of gasoline. I wonder what the fuel consumption per hour is for a typical lawnmower at full throttle? (That's how most of them are run when cutting grass.)
From that we could calculate how many hours the boys would have to run their two push mowers to save 880 gallons of gas. That's for "more than two dozen" clients in their first year. Their available working time would be constrained by sleep, eating and during the school year, school time and doing homework.
The only scientifically proper* way to directly compare mower VS car pollution is to determine how much and what types of chemical compounds each produces per gallon of gasoline burned. That of course includes any evaporation from the tank. Do any of these small engines have a method for running evaporative emissions into the combustion chamber?
If the comparison is time based, the eight cars "win" the pollution contest because they'll definitely burn more per time unit.
*OK, there are other ways, but that's the simplest. Even then the fuel use per time unit of the cars could have an effect.
P.S. Don't bother attempting to question the kids about their stuff. Their father screens their e-mail and calls any questions or presentations of contradictory data a 'diatribe' and says you are wrong. (I expect he intercepted plenty of e-mails after that article.) He replied with a couple of URLs they got their information from, one on maintaining your mower (good advice) and one about how small engines are worse polluters than cars. I was simply suggesting to the teens what they could research to conduct their own scientific investigation instead of relying on other people's info. It'd be a project they could use for their Eagle Scout qualifications.
August 1st, 2nd, 3rd, 2014
"I am a machine. I am a weapon of war. I am a destroyer of life in the service of life, the sword and shield of my human creators." Bolo Invincibilus
, Mark XXIII, Model B (Experimental) 0075-NKE "Nike".