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Location: East of Seattle since 1992, 615' Elevation, Zone 8b - originally from SF Bay Area
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Whatever the accurate number might be, I would expect that it's going up with the popularity of the turbocharged engine. Forced induction means a lot more air going into the burning of the fuel. Even on naturally aspirated engines the idea of "more air=more power" has made the cold air induction system or more free-flowing air filters like K & N popular. My F150 5.0 V8 is 385 horsepower, but the little 2.7 V6 gets almost as much (325) thanks to the two turbos sucking air.
Whatever the accurate number might be, I would expect that it's going up with the popularity of the turbocharged engine. Forced induction means a lot more air going into the burning of the fuel....
Relative to atmospheric composition both the CO2 and the oxygen are minuscule amounts. While the amount of oxygen consumed is irrelevant the concern of course is CO2 is a greenhouse gas and really the only gas that should be a discussion here since even that minuscule amount will play a role in global warming. Throwing out the oxygen amounts is either because the OP is misinformed or simply trying to prey on peoples lack of knowledge. A turbocharger increases efficiency reducing fuel consumption, lowering fuel consumption lowers CO2 emissions.
Relative to atmospheric composition both the CO2 and the oxygen are minuscule amounts. While the amount of oxygen consumed is irrelevant the concern of course is CO2 is a greenhouse gas and really the only gas that should be a discussion here since even that minuscule amount will play a role in global warming.
The entire discussion of oxygen consumption is a mildly interesting scientific diversion, since O2 is not "consumed" the way hydrocarbon fuels are. Any nearby tree produces the stuff by the ton.
It's also 20% of the atmosphere, which isn't "miniscule" on most scales.
I think too many people got hung up on the wrong end of the op. That a gallon of gas adds about 17 pounds of CO2 to the atmosphere is the critical point... and while the O2 was there and will come back courtesy of the local dandelion patch, the carbon is essentially a new introduction to the ecosphere.
In case you weren't aware, it consumes approximately 20 pounds of oxygen and produces about 17 pounds of CO2. Yeah, I'd rather be walking too.
Every person emits the equivalent of approximately two tons of carbon dioxide a year from the time food is produced to when the human body excretes it, representing more than 20 percent of total yearly emissions. That is what a study by researchers in Spain says, confirming for the first time that human excrement contributes to water pollution, primarily with nitrogen and phosphorus.
In one day, the average person breathes out around 500 litres of the greenhouse gas CO2 – which amounts to around 1kg in mass. This doesn’t sound much until you take into account the fact that the world’s population is around 6.8 billion, collectively breathing out around 2500 million tonnes of the stuff each year – which is around 7 per cent of the annual CO2 tonnage churned out by the burning of fossil fuel around the world.
A turbocharger increases efficiency reducing fuel consumption, lowering fuel consumption lowers CO2 emissions.
This may be true in diesels, but it's far from that straightforward in gasoline engines.
While a turbocharger does increase volumetric efficiency, this is not remotely the same thing as fuel efficiency. Rather, it's a measure of how much air you're able to stuff into a cylinder. You can get numbers greater than 100% because (obviously) a turbocharger is a compressor.
Diesels get increased fuel economy and power from turbos for a variety of reasons, but this is not universally true of gasoline engines - most in fact, get worse fuel economy, for the following reasons:
1) A gas engine with a turbo, all else being equal, will have a lower static compression ratio than one that's naturally aspirated. When you're off boost, you have a lower compression ratio, which reduces efficiency.
2) Because of the increased volumetric efficiency, turbocharged cylinders run a lot hotter. Intercoolers help, but most turbocharged engines either (or both) pull timing or run rich. Both of these reduce efficiency and hurt fuel economy while on boost. It's possible to build a turbocharged engine which doesn't need to pull timing or run rich, but there are other design sacrifices for making this happen.
You can't just slap a turbo on an engine and expect better economy. You probably will get worse economy even with a good tune with economy as the focus. To have any chance, you need to design the engine around it, and even then most economy benefits will not be there vs an equally sized NA engine, but rather, will be there when compared with an otherwise larger engine that was needed to produce the same power.
This may be true in diesels, but it's far from that straightforward in gasoline engines.
While a turbocharger does increase volumetric efficiency, this is not remotely the same thing as fuel efficiency. Rather, it's a measure of how much air you're able to stuff into a cylinder. You can get numbers greater than 100% because (obviously) a turbocharger is a compressor.
Diesels get increased fuel economy and power from turbos for a variety of reasons, but this is not universally true of gasoline engines - most in fact, get worse fuel economy, for the following reasons:
1) A gas engine with a turbo, all else being equal, will have a lower static compression ratio than one that's naturally aspirated. When you're off boost, you have a lower compression ratio, which reduces efficiency.
2) Because of the increased volumetric efficiency, turbocharged cylinders run a lot hotter. Intercoolers help, but most turbocharged engines either (or both) pull timing or run rich. Both of these reduce efficiency and hurt fuel economy while on boost. It's possible to build a turbocharged engine which doesn't need to pull timing or run rich, but there are other design sacrifices for making this happen.
You can't just slap a turbo on an engine and expect better economy. You probably will get worse economy even with a good tune with economy as the focus. To have any chance, you need to design the engine around it, and even then most economy benefits will not be there vs an equally sized NA engine, but rather, will be there when compared with an otherwise larger engine that was needed to produce the same power.
Well only a moron would slap a turbo on an engine and expect better efficiency.
The use of turbos and superchargers to increase efficiency is by installation of a smaller engine with the same power output. Smaller engines are lighter reducing rolling resistance, permitting other weight savings, and reduces internal losses in the engine.This increases overall efficiency.
Even at a facile level suppose a 3.6L 300 hp engine is replaced with a 2.0L 300hp turbo, a 3.6L is probably running at 500-600lbs, the 2.0L 300-350lbs so a 200lb weight saving (10% for a 1t vehicle), for zero power loss. That doesn't include reduced weights of other components (suspension, brakes) because of the reduced weight of the engine.
Of course. This wasn't clear in the post I quoted.
Downsizing also doesn't work below a certain point. The new 4 cylinder turbo Silverado gets lower economy than its competitors' v6 offerings, suggesting they may have downsized too far and the engine is more often operating outside of its most efficient range - every engine has a window of load and rpm in which they're most efficient.
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Damn. I had plans after that. No point in recycling now, I guess.
