I don't necessarily believe there is no CFC/ozone connection, but I do find it "interesting" that NASA triumphantly announced CFC levels are down and the hole is measurably smaller literally just a few months after a study in Nature showed Chinese factories have been cranking out CFCs at levels that nearly wiped out everything the west did to eliminate them (80% of 1987 levels, where we "should" have been near 0% for something like 10 years now). Something doesn't add up. But global warming is like religion and politics, you'll never convince anyone who disagrees with you, regardless of your position.
The sad truth is that the change is based upon fuel economy... and not because either refrigerant actually has anything to do with fuel economy.
The marketing-friendly explanation for the switch is because R134a is considered a greenhouse gas, but that is not the ozone layer problem (real or not). Refrigerants are assigned a "global warming potential" (GWP) and a separate ozone depletion potential (ODP) rating. Lower GWP is better and is based on CO2 which has GWP of 1. R134a was rated 1430 where as R1234yf is rated as just 1, the same as pure CO2. Good old R12 was rated at 2400, and in the earliest days of commercially-available refrigerants there was R11 which is way up there at 4000. GWP is not the same as ozone depletion potential (ODP), so the change wasn't related to that. R12 is the baseline for ODP at 1.0, but both R134a and R1234yf are rated 0.0.
However, there is no mandate to use it. It's measurably less efficient, it costs more, it's harder and more expensive to work with, it's harder on the equipment, and for extra bonus points, it's mildly flammable (to the point both SAE and CARB are pushing to prohibit availability to the public). So why would any auto-manufacturer bother?
Because the EPA gives CAFE CO2 credits for R1234yf.
The credit is 13.8 grams/mi for cars and 17.2 grams/mile for trucks. The LGZ Colorado is rated by the EPA at 9.2 tons of CO2 per year assuming 15,000 miles, which is 562.45 grams/mile, so we endure shitty AC for a 3% bump to the truck's CAFE rating.
I have a secret theory that the hippies keep pushing increasingly worse refrigerants because they like BO.
2017 Colorado LT V6 CCSB 2WD • mfg date 11-16 • Belltech 999SP 3/4 drop • Raceline 927M Mamba HD 20x9 wheels • all LED lighting inside and out • DRL relocation harness • LineX • Lomax Tri-Fold aluminum tonneau • de-badged • bowtie blackout • painted pinch-weld & window trim • power tailgate lock • Pedal Commander • Katzkin leather • tint • Kicker amp/sub
Last edited by MV10; 09-14-2018 at 10:20 AM.