# 2 stroke lawnmower = 40 idling cars?
**URL:** https://boards.straightdope.com/t/2-stroke-lawnmower-40-idling-cars/246002
**Category:** Factual Questions
**Created:** [May 19, 2004, 6:26pm UTC](https://boards.straightdope.com/t/2-stroke-lawnmower-40-idling-cars/246002 "2004-05-19T18:26:19Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@emacknight](https://boards.straightdope.com/u/emacknight)
#### Post date: [May 19, 2004, 6:26pm UTC](https://boards.straightdope.com/t/2-stroke-lawnmower-40-idling-cars/246002/1 "2004-05-19T18:26:19Z")
I was listening to an environmentalist on the radio the other day. She was pushing to get people to trade in their 2 stroke lawnmowers for more enviro-friendly 4 stroke. That’s all well and good, but she made the above comment:
“A 2 stroke lawnmower running for an hour produces as much pollution as 40 new cars idling.”
Is there any truth to this statement? Seems a bit extreme. I’m aware of the problems with 2 stroke engineers, but is it really THAT bad?
---
### Author:  [@Munch](https://boards.straightdope.com/u/Munch)
#### Post date: [May 19, 2004, 6:31pm UTC](https://boards.straightdope.com/t/2-stroke-lawnmower-40-idling-cars/246002/2 "2004-05-19T18:31:26Z")
The fact that she wasn’t pushing one of the new electric mowers that are out lends evidence to her being a complete moron.
---
### Author:  [@Rick](https://boards.straightdope.com/u/Rick)
#### Post date: [May 19, 2004, 7:25pm UTC](https://boards.straightdope.com/t/2-stroke-lawnmower-40-idling-cars/246002/3 "2004-05-19T19:25:18Z")
While I have not seen the tailpipe emissions from a two stroke engine, I can tell you that
A) They are **way** dirtier than 4 stroke motors
B) The main culprit is excess hydrocarbons due to the oil being mixed into the gas
C) No emission controls on a lawnmower
on the other hand, cars are getting cleaner all the time. We have cars out there now that emit almost 0 PPM hydrocarbons. Now admittedly there are a lot more parts per million passing through a car engine than a lawnmower (look at the size of the tailpipes) but the lawnmower is probably putting out between 2,000 and 5,000 PPM (SWAG based on what I know about engines) a new car might be putting out -3 - 5 PPM. Yes, you can see negative PPM of hydrocarbons, dirty incoming air, and a very good converter.
My question is who sells 2 stroke lawnmowers? I don’t think I have ever seen one in the last 20 years or more. Chainsaws, weed whackers, leaf blowers sure, lawnmowers nope.
I have also been told by emission engineers that current cars are so much cleaner than older cars that a current production car driving @ 60mph puts less junk into the air than a car from the 60’s did when parked.
---
### Author:  [@JerH](https://boards.straightdope.com/u/JerH)
#### Post date: [May 20, 2004, 1:45pm UTC](https://boards.straightdope.com/t/2-stroke-lawnmower-40-idling-cars/246002/4 "2004-05-20T13:45:10Z")
Most lawnmowers these days use 4-cycle engines; still dirtier than car engines, but cleaner than 2-cycle. A lot of smaller equipment (chainsaws, trimmers, leaf blowers) still use 2-stroke engines. I remember a similar statistic being bandied about in the mid-late 1990s (when I had a job in the power equipment industry), and upon further examination their statistic was based on running an older engine at full throttle for the entire time - which isn’t really how the equipment is used.
---
### Author:  [@Shoeless](https://boards.straightdope.com/u/Shoeless)
#### Post date: [May 20, 2004, 1:50pm UTC](https://boards.straightdope.com/t/2-stroke-lawnmower-40-idling-cars/246002/5 "2004-05-20T13:50:01Z")
AFAIK, Lawn Boy still makes 2-cycle lawnmowers.