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#97 of 116 Re: VW [alp8]
Sep 14, 2006 (2:37 pm)
"Reliability should play a role in the "green-ness" of a car"
I'd say "longevity".
Some very reliable cars get worn out very quickly, and some unrelaible cars will run forever if you swap a part or two a year.
#98 of 116 life cycle analysis
Sep 14, 2006 (3:19 pm)
no question this is a complicated area
I know midcow was kidding, but there are very real complexities in this field (yes, it is a "field")
the longevity issue is an interesting one, since you'll burn more fuel in your car over its life than was used to manufacture the car (including all the materials and components in the car). I assumed otherwise, but I was edumacated on that issue.
in fact, longevity may be a bad thing - we ain't doing anyone any favors driving a 25-year old Bronco that gets 13 mpg, are we?
maybe what you guys are saying is that we can't possibly know which car is greener - it's too complicated - so we shouldn't discuss it
I can buy that
#99 of 116 Re: life cycle analysis [alp8]
Sep 14, 2006 (9:06 pm)
No--but it is a really complex problem.
What if a car makes more pollution during its operation but lasts twice as long? Will there be less pollution than running a cleaner vehicle but having to build and dispose of another one?
How do you compare a car that makes less pollution while driving versus a car that makes less pollution during its manufacture and disposal, if lifetimes are similar?
How do you compare a car that uses less of a highly refined fuel, fuel that took more energy to produce, and caused more pollution during its manufacture?
That's why i think it's pointless to attack VW. Depending on the coefficients, a VW TDI may or may not be "greener" than a similar hybrid.
And i think we ought to agree that both a TDI and an insight are a step forward from a suburban.
We care about the environment right? Not an attachment to one particular technology?
#100 of 116 Re: life cycle analysis [dhanley]
Sep 15, 2006 (7:52 am)
That ashes-to-ashes study tried to do just that, but they made a very bad assumption - that all cars last the same number of miles - I think it was 100k or so. That's far too little for most cars.
I'd like to see that study done using the actual average life of a car. They can get the registration data from RL Polk.
Then rate the cars on the amount of energy they use per year.
#101 of 116 Re: life cycle analysis [ateixeira]
Sep 15, 2006 (10:11 am)
Yeah--honestly, i'm quite skeptical of the ashes-to-ashes study.
I don't see how some cars that are so similar can have such different numbers. For example, a crossfire rated 1/3 the energy cost of a SLK. However, a crossfire is just a reskinned SLK.
I also have a hard time believing that an h2 can be so energy efficient compared to, say, an impala. Maybe there's some old machining tools for which the cost has been amortized for a long time, but there's just so much more steel/rubber/plastic being both produced and disposed of in the end. Never mind the fuel economy...
#102 of 116 Re: life cycle analysis [dhanley]
Sep 15, 2006 (10:13 am)
yes, I agree - I wasn't bashing VW's diesel, I was bashing VW, generally
I am not an anti-diesel guy, provided the air emissions are acceptable. And I am not saying that VW's TDI emissions are NOT acceptable. I haven't analyzed it that much.
#103 of 116 Re: life cycle analysis [ateixeira]
Sep 15, 2006 (10:20 am)
the ashes to ashes study is the best effort thus far, that I know of
I like the approach, though there are certainly valid criticisms of it, such as the one you mentioned.
am not sure what the "best" way to do it is - mpg is clearly not the only relevant factor.
we do need to keep in mind that air emissions may be a more critical factor for some (i.e. those that live in severely polluted air basins) than for others
and you'll always have the debate from the guy who is anti-nuke that a car produced using nuclear energy (electricity from a nuke plant) is less "green" than one from a natural gas fired plant, for example
I think using the 100k parameter is not a bad one. Am sure it could be improved, of course.
as an aside, I do not "judge" anyone based on the car they drive. Even if you do judge people for anything, you have to keep in mind that the guy driving 90 miles/day in a Civic Hybrid is hurting the environment more than the women drving 5 miles/day in her Volvo XC90 getting 15 mpg and then hopping the local train.
I get 22 mpg, but I also invested 20 grand in a solar array for my rooftop. Am I bad for the environment because I'm not getting 30 mpg? I'd feel a lot worse if I lived 45 miles from work getting 30 mpg than I do getting 22 mpg living 15 miles from work. My choice of where to live and work has enviro consequences. So it isn't JUST about your car's mpg.
But we all know that.
#104 of 116 Re: life cycle analysis [dhanley]
Sep 15, 2006 (10:21 am)
I assumed the SLK had nifty aluminum and other high-tech materials in it, to keep the weight down. Less so with the Crossfire.
#105 of 116 Re: life cycle analysis [alp8]
Sep 15, 2006 (12:47 pm)
"I assumed the SLK had nifty aluminum and other high-tech materials in it, to keep the weight down. Less so with the Crossfire."
Could be--but i think the shell of the cars is steel in both cases, and it's pretty much just a reskin.
Even so, three times?!?
Agree with pretty much everything else. I don't drive to work at all, with gas usage being a big reason.
#106 of 116 Re: life cycle analysis [dhanley]
Sep 15, 2006 (1:39 pm)
nice work!!! (not driving to work)
I bet your stress level is 50% of the average commuter, too
yeah, 3X seems a bit much. It certainly makes you wonder about the analysis. I wonder if it's stupid stuff like the MB (DC) showrooms are all new and spiffy whereas the Chrysler showrooms are old