3 ms·

I think the 40 km/l is unrealistic -- that's 95 mpg. Your average car is apparently(?) under a quarter of that, 22 mpg [3]. Although I feel like this is probabl

I think the 40 km/l is unrealistic -- that's 95 mpg. Your average car is apparently(?) under a quarter of that, 22 mpg [3]. Although I feel like this is probably a low-ball (possibly old) figure? My guess would've been like 30 mpg, but I don't know how much of the population has a new car. The source I had was [1] which said a plane emits ~0.9 tons of CO2/person/round-trip, whereas the average car emits ~4.6 tons/year [2]. At 1.7 persons/car [3] that's 2.7 tons CO2/person/year. Now interestingly, I can't seem to see a source for the 0.9-ton figure; I do see some other sites [4] that claim a one-way flight of that distance emits 2.8 tons, which is a 6x difference... I'm not sure which one is accurate. But there's another site [5] quoting a similar figure to the 0.9 tons. So funny enough I'm kinda back where I'm started... not sure what the right figure is to even 5x... [1] https://www.nytimes.com/2017/07/27/climate/airplane-pollution-global-warming.html https://www.nytimes.com/2017/07/27/climate/airplane-pollutio... [2] https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-typical-passenger-vehicle https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-t... [3] https://www.fhwa.dot.gov/tpm/guidance/avo_factors.pdf https://www.fhwa.dot.gov/tpm/guidance/avo_factors.pdf [4] https://content.sierraclub.org/outings/carbon-offsets https://content.sierraclub.org/outings/carbon-offsets [5] https://www.smithsonianmag.com/travel/if-you-travel-and-care-about-environment-you-should-buy-carbon-offsets-180952222/ https://www.smithsonianmag.com/travel/if-you-travel-and-care...

pbhjpbhj 7y ago
>My guess would've been like 30 mpg, but I don't know how much of the population has a new car. // I just ditched a 15yo 7 seater (Opel/Vauxhall Zafira) with engine troubles (burning a lot of oil - maybe a piston compression problem; leaking exhaust manifold), and having a roofbox, and it was still doing 34mpg (UK; that's 15km/l) with primarily short journeys. Newer cars must do 40mpg as a minimum, surely?
- bzbarsky 7y ago
  Newer cars tend to be larger and heavier than older cars, which does not help fuel efficiency. For the US specifically, https://www.nytimes.com/interactive/2018/04/03/climate/us-fuel-economy.html https://www.nytimes.com/interactive/2018/04/03/climate/us-fu... says that in 2016 new "cars and light trucks (i.e. SUVs)" in the US average 24.7 mpg. Based on the charts, restricting to just cars gives you something like 36mpg in the US in 2016. Note that the EU number is much higher at ~46mpg, likely due to the cars being on average smaller. Though I'm not sure what to make of the fact that the charts seem to show both cars _and_ light trucks at above 25mpg for the US in 2016; hard to reconcile that with the 24.7 number. Also see the note about how SUVs and vans are considered "cars" in the EU but "light trucks" in the US... Anyway, the upshot is that it's certainly possible to get something that will get you over 40mpg, but the average is below that even for new vehicles, in the US.

pbhjpbhj 7y ago

>My guess would've been like 30 mpg, but I don't know how much of the population has a new car. // I just ditched a 15yo 7 seater (Opel/Vauxhall Zafira) with engine troubles (burning a lot of oil - maybe a piston compression problem; leaking exhaust manifold), and having a roofbox, and it was still doing 34mpg (UK; that's 15km/l) with primarily short journeys. Newer cars must do 40mpg as a minimum, surely?

bzbarsky 7y ago
Newer cars tend to be larger and heavier than older cars, which does not help fuel efficiency. For the US specifically, https://www.nytimes.com/interactive/2018/04/03/climate/us-fuel-economy.html https://www.nytimes.com/interactive/2018/04/03/climate/us-fu... says that in 2016 new "cars and light trucks (i.e. SUVs)" in the US average 24.7 mpg. Based on the charts, restricting to just cars gives you something like 36mpg in the US in 2016. Note that the EU number is much higher at ~46mpg, likely due to the cars being on average smaller. Though I'm not sure what to make of the fact that the charts seem to show both cars _and_ light trucks at above 25mpg for the US in 2016; hard to reconcile that with the 24.7 number. Also see the note about how SUVs and vans are considered "cars" in the EU but "light trucks" in the US... Anyway, the upshot is that it's certainly possible to get something that will get you over 40mpg, but the average is below that even for new vehicles, in the US.