Greener Mowers

AN ENVIRONMENTALLY FRIENDLY MOWER
A customer recently sent me a letter after reading an article in "National Wildlife" that featured the picture of a smoking mower and quoted that "one mower used weekly during the growing season pollutes as much as 43 late-model cars". I decided to do some research to better understand and communicate the issue.

Emissions from engines are primarily caused by incomplete (in-efficient) burning of fuel and fuel additives. Two primary reasons for an efficient or in-efficient engine include; 1) engine design and 2) engine condition.

Emissions and Engine Design - Some engines are more efficient and less polluting due to their design. The worst polluting are 2-cycle designs that require the mixing of oil with gas, as the engine has no internal oil source. As of 2004, no more of these mowers are produced for sale in the USA. Chainsaws and trimmers still use this style of engine as it is very light-weight, but the manufacturers have changed the oil additive to less polluting formulas. Further, the engines have been "leaned" to use a lesser amount of oil. The current mixtures are 50 parts fuel to 1 part oil. 4-cycle engines are generally less polluting than 2-cycle designs, but other features such as over-head-valve (OHV) technology further increase efficiency, and decrease the emissions.

"Air index" tags identify the "greener" mowers. The EPA is driving the changes in small engine emissions. Every mower sold today must have an "air index" tag attached to the engine. The air index shows the polluting measure of that engine on a scale of 0 to 10 relative to other engines in its class. 0 is the best and 10 the worst. Manufacturers are financially penalized by the EPA for combined sales of engines that exceed their "air index" goals.

By 2011, a new "phase" of EPA regulations will be in place holding the manufacturers to even stricter standards. You will see a variety of design changes soon to begin meeting the new codes.

Emissions and Engine Condition - The second big (probably bigger) pollution cause is from out-of-tune mowers. Clogged air filters, fouled spark plugs, old gas and dull blades all contribute to an in-efficiently running mower. The amount of unburned gas being spewed into the air can be substantial from something as simple as a dirty air filter. Perhaps it was an out-of-tune, or older mower they used for the "National Wildlife" article?

To go "green" try the following EPA suggestions:

1. Avoid Spilling Gasoline!
2. Maintain Your Equipment - Keep your equipment tuned and sharp
3. Buy Mowers with Low "Air Index" Numbers or Alternative Fuels
4. Use Manual Equipment, with no engine.
5. Reduce Mowing Time - Try low-maintenance grasses or smaller lawns
6. Recycle Old Equipment - Do not use old, inefficient equipment