Not for long my man. Article and govenrment websiteCamaro wrote:QUOTE (Camaro @ Mar 1 2014, 09:34 AM) Gasoline tax is amongst the most regressive tax possible. In America a car is pretty much necessary in most places. We DO have gas tax, it is highly regressive and hurts the poor the most.
And I reiterate, that displacement tax is asinine. Tax based on the estimated fuel consumption like we do in the US. (if it gets worse than X mpg, it is hit with the gas guzzler tax). Of course, our tax is pointless because the only cars that hit gas guzzler are expensive sports cars.
Ok lets get the cards on the table. The current US government policy on MPG is so $#@!ing convoluted and based on spurious math it boggles the mind.
I'd like to congratualte the poo flinging goofballs who came up with the 2012-2016 regualtion based on vehicle footprint. That team would win the pants on the head stupid award but sadly several other teams have them beat hands down. In secomd place to wear the pants is eMPG... words escape me on this one other than to wonder if it was wild eyed do-gooder incompetency or bribery. *drum roll* The group that gets to wear the pants on the head is the energy credit based on green house gases vs mpg group. To be fair to the others the winners they started with the other's gross incompetence/nefarious contributions but oh how they ran with it.
Electric cars, as we have learned (hopefully) are pretty energy inefficient when you look at the total picture and criminally so in all climates that are not temperate, get a doubler for fleet mpg. Hybrids *sighs* uses a mechanical engine to generate electricity to drive an electric motor meant to reduce green house gases is a cruel joke. Even in electric mode they are penalized by hauling the mechincal bits so are always less efficient that even electric cars.
Conclusion: The twofer multiplier given to electric/hybrid cars will drive more onto the roads which means WORSE levels of greenhouse gas produciton in all but a few locations in the US
GWP numbers for refrigerants are, to say the least, highly controversial but let's take them at face value for a split second. Car companies are in two camps now between R123(4yf) and CO2 for their new refrigerants. Ok split seccond over even the IPCC calls GWP guess work. The magazine article, well written and informed btw, did $#@! up by saying either new working fluid based system is more efficient. I will not bore you with the details for brevity sake just state that the paper is obviously slanted to minimizing the efficincy loses of going to a R123(4(yf(ez)) system... super heat setting, compressor operting range, the use of an IHX, and a 70.4% confidence. However lets take 10% worse efficiency at face value.
This paper on CO2 vs r134a has the details but performance is about 50% worse for a CO2 vs. r134a at even moderate rpms (3000 RPM). It is instructional to note that they published 1000 rpm numbers with a straight face. Your compressor generally operates above 3000 rpm and 1000 rpm is stall speed of the engine (compressor pulley ratios are not 1:1)... the higher the rpm the worse the comparison becomes between the two systems. I will say the numbers are surprising to me and I think the delta is to high based on experience. No matter what R134a > R1234yf > CO2 the deltas are open to manipulation.
Alrighty then now that we can see that all other refrigerants will absolutely cause more CO2 emissions we need to evaluate the contributions of the refrigerant itself to the enivirnoment as well. We will assume that all of the working fluids eventually leak into the atmosphere. The charges of an AC system vary wildly but lets use 22oz which is typicallish of one of the great big passenger trucks. R134a has a GWP of 1300, R1234yf is 8 (if memory serves me), and CO2 as the baseline is one.
R134a charge 22oz
R1234yf charge is typically a bit higher but lests say they are the same
CO2 charge is higher (so much that a leak into the passenger compartment is a safety concern) but lets use 22 as well
Im stacking the deck against 134a in a nutshell. We can twiddle the dials to death but for the sake of discussion
22*28.3*1300/1000 = 810.5 kgs of CO2 penalty for using r134a vs CO2
22*28.3*(1300/8)/1000 = 101.3 kg of CO2 penalty for usin r134 vs r1234yf
22*28.3*8/1000 = 5kg of CO2 penalty for using r1234yf vs CO2
ok than now we need to look at how much CO2 is made by burning a gallon of gas/diesel
8.9kg/gal for gasoline 10.2kg for diesel (diesel makes more CO2 than gasoline however it tends to get higher mpg)
So anything more than 91 gallons extra gas burned for the AC means don't do it for CO2 and 11.4 gallons of gas for r1234 the same
50000 miles equivalent AC on (it is always working just not as much until the temp drops below 35F... dehumidification is why... so we need to gin up an equivalent)
r1234yf is 10% less efficient and CO2 50% less efficient
What mpg increase do you need to overcome the efficienct penalty vs the net CO2 improvement due to wroking fluids green house gas contibution in CO2?
The penalty in miles is 333.33 and 3000 r1234 and CO2 respectively
you need approx 29.2 and 33.3 mpg respectively to switch.
Note: The more you use AC the less likely it will be a benefit to switch and those CO2 efficiency numbers are probably high.
oops to many numbers at once redid mpg and it shows it isn't as bad as I thought for CO2... the statement about CO2 for europe is because teh German car companies are driving it is still true fwiw
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