5 ms·

I find this hard to believe. I remember mowing the lawn for my parents, powering my ridealong lawn mower with a few gallons of gas for an hour or two (or maybe

by mjfl 5y ago

I find this hard to believe. I remember mowing the lawn for my parents, powering my ridealong lawn mower with a few gallons of gas for an hour or two (or maybe 30 minutes, I don't remember how long it took me). My car, at best, would drive for an hour on a few gallons of gas. So about the same amount of time. What gives?

jacobolus 5y ago
This is emissions of miscellaneous hydrocarbons, NO, NO₂, and CO. Not CO₂. If you add a catalytic converter etc. you could cut most of it. But then the engine would be much bulkier and more expensive.
- dane-pgp 5y ago
  > NO, NO₂, and CO. Not CO₂. I can't decide if that's a triple negative or a quadruple negative.
grecy 5y ago
The 2 stroke leaf blower is literally burning oil to run, so the emissions are much, much worse. (that's how 2 stroke engines work). Also note your ride on mower (and other small IC things) don't have catalytic converters or anything at all to manage emissions, so the stuff coming out the exhaust is multiple orders of magnitudes worse - especially for the user who is standing right there breathing it in. It isn't just about gallons consumed per hour, it's about what comes out the exhaust.
maxerickson 5y ago
The test is measuring emissions, not efficiency. From the link: The Results During the FTP 75 test, exhaust gas from the vehicle's tailpipe is captured and analyzed by laboratory-grade equipment that's so expensive it makes the Kentucky Derby look like the Pinewood Derby. This lab equipment measures all kinds of compounds coming out of the tailpipe but the three we will focus on are those with which EPA and CARB are primarily concerned, namely, non-methane hydrocarbons (NMHC), oxides of nitrogen (NOx) and carbon monoxide (CO). (then there's a table listing the results...)
magicalhippo 5y ago
Well two-stroke burns the oil as well, so that should be a big difference right there. The car should also have a more efficient combustion, due to all the electronics, along with a catalytic converter to meet the emission requirements. Note they talk about hydrocarbon emissions, not just CO2.
Misdicorl 5y ago
Your car has a good engine (mostly because it's regulated). Your lawnmower has the cheapest possible engine that will spin a blade. The cheap two cycle engine does exhaust and injection in the same cycle. Inevitably a large fraction of the injected fuel is also exhausted. How that tired back to green house gases I'm not totally sure, but it's certainly very bad for your lung health to breathe it!
dragonwriter 5y ago
Cars, among other things that have been mentioned, have catalytic converters.
- dredmorbius 5y ago
  And four-stroke engines, and a separate oil manifold rather than a fuel-oil mix.
caconym_ 5y ago
The typical small two-stroke engine has two big problems that cause hilariously bad emissions: 1) The lubricating oil is mixed into the fuel and burned in the combustion cycle. The combustion products of this oil are not clean. 2) They combine exhaust and intake into a single "stroke", i.e. the downstroke after ignition, which can result in unburnt aerosolized fuel escaping with the exhaust. Additionally, fuel injection systems can typically achieve better emissions than carburetors can. AFAIK small two-strokes (and some four-strokes like small outboard motors, etc.) are largely the last bastion of carburetors in engines manufactured today.

by mjfl 5y ago

jacobolus 5y ago

This is emissions of miscellaneous hydrocarbons, NO, NO₂, and CO. Not CO₂. If you add a catalytic converter etc. you could cut most of it. But then the engine would be much bulkier and more expensive.

dane-pgp 5y ago
> NO, NO₂, and CO. Not CO₂. I can't decide if that's a triple negative or a quadruple negative.

grecy 5y ago

The 2 stroke leaf blower is literally burning oil to run, so the emissions are much, much worse. (that's how 2 stroke engines work). Also note your ride on mower (and other small IC things) don't have catalytic converters or anything at all to manage emissions, so the stuff coming out the exhaust is multiple orders of magnitudes worse - especially for the user who is standing right there breathing it in. It isn't just about gallons consumed per hour, it's about what comes out the exhaust.

maxerickson 5y ago

The test is measuring emissions, not efficiency. From the link: The Results During the FTP 75 test, exhaust gas from the vehicle's tailpipe is captured and analyzed by laboratory-grade equipment that's so expensive it makes the Kentucky Derby look like the Pinewood Derby. This lab equipment measures all kinds of compounds coming out of the tailpipe but the three we will focus on are those with which EPA and CARB are primarily concerned, namely, non-methane hydrocarbons (NMHC), oxides of nitrogen (NOx) and carbon monoxide (CO). (then there's a table listing the results...)

magicalhippo 5y ago

Well two-stroke burns the oil as well, so that should be a big difference right there. The car should also have a more efficient combustion, due to all the electronics, along with a catalytic converter to meet the emission requirements. Note they talk about hydrocarbon emissions, not just CO2.

Misdicorl 5y ago

Your car has a good engine (mostly because it's regulated). Your lawnmower has the cheapest possible engine that will spin a blade. The cheap two cycle engine does exhaust and injection in the same cycle. Inevitably a large fraction of the injected fuel is also exhausted. How that tired back to green house gases I'm not totally sure, but it's certainly very bad for your lung health to breathe it!

dragonwriter 5y ago

Cars, among other things that have been mentioned, have catalytic converters.

dredmorbius 5y ago
And four-stroke engines, and a separate oil manifold rather than a fuel-oil mix.

caconym_ 5y ago

The typical small two-stroke engine has two big problems that cause hilariously bad emissions: 1) The lubricating oil is mixed into the fuel and burned in the combustion cycle. The combustion products of this oil are not clean. 2) They combine exhaust and intake into a single "stroke", i.e. the downstroke after ignition, which can result in unburnt aerosolized fuel escaping with the exhaust. Additionally, fuel injection systems can typically achieve better emissions than carburetors can. AFAIK small two-strokes (and some four-strokes like small outboard motors, etc.) are largely the last bastion of carburetors in engines manufactured today.