If you check out Neuton Mowers, they're these battery-powered lawn mowers. I get the whole non-polluting, lower noise thing. But their comparison chart leaves something to be desired on the honesty scale.
Take a look at the graphic from their front page:
Two things strike me as a bit odd. I currently have one of these "Old" mowers. Notice that they characterize my mower as "Heavy." They don't say how heavy, but I'd estimate mine between 40 and 50 pounds. Then notice that their mower is "Only" 69 pounds. There is no way my old skool mower is 69 pounds. It's obvious why they just said "Heavy," because if they gave a typical number or an average, they couldn't compare favorably.
The other thing they say is that the Neuton makes "less than half the noise." Now, noise is traditionally measured in decibels, and lawnmowers are typically estimated around 90 decibels. The decibel scale is a logarithmic one, which always makes it a bit unintuitive. Now, half of 90 dB would be 45, but they say it's "less than half." Refrigerators humming are estimated at 40 dB. I find it hard to believe that this thing is somewhere around as loud as a refrigerator humming.
Finally, there's the fallacy of "emissions-free." Nothing is emissions free. At best we can say it does not directly emit pollutants after you purchase it. However, consider how many pollutants were generated to produce it in the first place. Compare that to the traditional mower and they probably compare more or less equally. While Neuton mowers may be zero emissions when operating, they are not zero pollution. Your coal-fired electric plant provides the electricity that charges the batteries. And some day some really awful chemicals in the batteries have to be disposed of carefully when it has reached the end of its life. So zero emissions, yes. Zero pollution, no.