Smog rating of the 991.2
05-03-2018, 01:25 PM
#32
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05-03-2018, 01:32 PM
#33
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What is the relationship between smog and mpg? Is there any? Any correlation? Thank you.
05-03-2018, 01:57 PM
#34
Pro
8.89 × 10-3 metric tons CO2/gallon gasoline × 11,443 VMT car/truck average × 1/22.0 miles per gallon car/truck average × 1 CO2, CH4, and N2O/0.989 CO2 = 4.67 metric tons CO2E/vehicle /year
05-03-2018, 02:13 PM
#35
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Thread Starter
A car can have a decent mpg rating but may emit lots of other pollutants not scrubbed by the catalysts. Like diesel engines. Even with gasoline engines, not necessarily correlated.
05-03-2018, 02:29 PM
#36
Is this what you are referring to? The number from 1-10?
05-03-2018, 02:30 PM
#37
05-03-2018, 02:35 PM
#38
RL Community Team
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Why is this a thread? I seriously don't understand. If you didn't like the emissions rating, why did you buy the car? I'm being serious when I ask that question.
05-03-2018, 02:35 PM
#39
Ok
I get it now I think. Since we're comparing sports cars to an SUV, the sports car is arguably more of a contributor to smog as it is a low carrying capacity vehicle. Seems like the EPA is trying to promote car pooling.
A Tahoe, tho stupid inefficient, is technically more efficient because you could carry more people with it than a Porsche ...
I get it now I think. Since we're comparing sports cars to an SUV, the sports car is arguably more of a contributor to smog as it is a low carrying capacity vehicle. Seems like the EPA is trying to promote car pooling.
A Tahoe, tho stupid inefficient, is technically more efficient because you could carry more people with it than a Porsche ...
05-03-2018, 02:36 PM
#40
RL Community Team
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Originally Posted by STG
Why do I need a car without an engine?
05-03-2018, 02:36 PM
#41
Still getting rids of cats. That back pressure needs to be reduced...
05-03-2018, 02:37 PM
#42
Pro
https://www.ucsusa.org/clean-vehicle...n#.WutCJmIpCaM
A car can have a decent mpg rating but may emit lots of other pollutants not scrubbed by the catalysts. Like diesel engines. Even with gasoline engines, not necessarily correlated.
Yes, you are correct that MPG ratings are not an absolute measure of emissions, however, the conversion of a gallon of gasoline into energy (heat) and gasses is an absolute. There is a correlation between the many gases and PM emitted by vehicles across the MPG spectrum, you just have to allow for some deviances based on external factors not related to the engine itself (e.g. emissions control equipment).
05-03-2018, 02:39 PM
#43
MPG testing is done in a controlled environment and this is really laid bare when it comes to forced induction engines that emit 5-6x the tested rate for pollutants when put under load (boost). This is what is driving the EU to overhaul their emissions regulations, to bring them in line with US regulations. EU emissions regs focused on CO2 and CO, and this favored solutions that enhanced fuel economy (backstory: climate change and reducing the dependence on Russian and Middle Eastern oil). US regulators built the regulatory regime around NOx and PM to combat the health effects of smog. Then we had dieselgate... which forced the EU to admit that a fuel economy focus and a testing regime that relied on test beds rather than real-world conditions were ripe for abuse. The EU is now refocused on NOx and CO2 with a phased rollout of real-world testing for compliance (I think 2021 is the final date). This means Euro6 is dead and fuel economy above all else is taking a back seat. It also means the downsizing of engines is coming to an end with manufacturers across the globe ditching their smallest displacement (sub-1.6 liter) engines that relied heavily on turbos.
Yes, you are correct that MPG ratings are not an absolute measure of emissions, however, the conversion of a gallon of gasoline into energy (heat) and gasses is an absolute. There is a correlation between the many gases and PM emitted by vehicles across the MPG spectrum, you just have to allow for some deviances based on external factors not related to the engine itself (e.g. emissions control equipment).
Yes, you are correct that MPG ratings are not an absolute measure of emissions, however, the conversion of a gallon of gasoline into energy (heat) and gasses is an absolute. There is a correlation between the many gases and PM emitted by vehicles across the MPG spectrum, you just have to allow for some deviances based on external factors not related to the engine itself (e.g. emissions control equipment).
This!
It's a controlled test. Can't be applied to real life directly (if ever). But, it's done in a laboratory, with scientists, and computers, and shiny things, and lab coats....so it's gotta be legit
05-03-2018, 05:16 PM
#45
Burning Brakes
MPG testing is done in a controlled environment and this is really laid bare when it comes to forced induction engines that emit 5-6x the tested rate for pollutants when put under load (boost). This is what is driving the EU to overhaul their emissions regulations, to bring them in line with US regulations. EU emissions regs focused on CO2 and CO, and this favored solutions that enhanced fuel economy (backstory: climate change and reducing the dependence on Russian and Middle Eastern oil). US regulators built the regulatory regime around NOx and PM to combat the health effects of smog. Then we had dieselgate... which forced the EU to admit that a fuel economy focus and a testing regime that relied on test beds rather than real-world conditions were ripe for abuse. The EU is now refocused on NOx and CO2 with a phased rollout of real-world testing for compliance (I think 2021 is the final date). This means Euro6 is dead and fuel economy above all else is taking a back seat. It also means the downsizing of engines is coming to an end with manufacturers across the globe ditching their smallest displacement (sub-1.6 liter) engines that relied heavily on turbos.
Yes, you are correct that MPG ratings are not an absolute measure of emissions, however, the conversion of a gallon of gasoline into energy (heat) and gasses is an absolute. There is a correlation between the many gases and PM emitted by vehicles across the MPG spectrum, you just have to allow for some deviances based on external factors not related to the engine itself (e.g. emissions control equipment).
Yes, you are correct that MPG ratings are not an absolute measure of emissions, however, the conversion of a gallon of gasoline into energy (heat) and gasses is an absolute. There is a correlation between the many gases and PM emitted by vehicles across the MPG spectrum, you just have to allow for some deviances based on external factors not related to the engine itself (e.g. emissions control equipment).
In contrast, the European fuel economy and emissions test have been garbage for years. Even as the Europeans criticize the Americans for polluting the earth, our testing protocols are substantially more rigorous than theirs.
The downsized turbo strategy also works very well on BMW and Mercedes models, though not so much on the really tiny turbos .For example a Chevy Malibu with the 1.5-liter turbo engine is in the boost way more often than a 991.2 in comparable driving. After all, the Chevy's engine is half as big and the car weighs several hundred pounds more.
As to the emissions, the CO2 emissions are directly proportional to the fuel used and there's no way to reduce them with after-treatment. However, the smog emissions, HC, CO, and NOx are limited to the same level across the board. A Ford F150 can emit no more than a FIAT 500. That's only possible because of the extraordinary effectiveness of modern catalysts. Same goes for particulates. There's an absolute limit per mile regardless of the size of the engine or the weight of the vehicle.