SAE rep: “Mercedes-Benz is full of it!”
Wayne Gerdes - CleanMPG
- Oct. 20, 2012
Mercedes Benz electrical motor plant in Berlin. It is but one way they are going to try and meet the CAFÉ standards… But not with the latest all-new environmentally friendly refrigerant.
Mercedes-Benz wishes to continue using R134a refrigerant in passenger cars as the upcoming all-new “environmentally friendly
” R1234yf refrigerant incurs too much risk according to its own internal testing.
Daimler provided SAE with findings from an internal investigation which raises questions on the safe usage of the new internationally recognized R1234yf refrigerant.
Up to now, the climate-friendly chemical was set to be used worldwide in the automotive industry and was extensively tested as both environmentally benign and accident safe. This was determined by numerous laboratory and crash tests carried out by international vehicle manufacturers and independent institutions.
Despite multiple confirmations of non-critical results, Daimler carried out a series of additional tests on the new refrigerant as part of a new real-life test scenario developed in-house which goes above and beyond the legally prescribed requirements.
Speaking with an individual working for SAE and who was personally involved in the new refrigerant standard and testing said in no uncertain term that Mercedes internal testing was far beyond any testing criteria anyone had ever conceived and the subsequent risks were out to 14 digits behind the decimal point.
“Having R1234yf refrigerant ignite under the hood after an accident is statistically about as remote getting killed in an elevator.”
In Mercedes test scenario, the refrigerant is dynamically dispersed at high pressure near to hot components of the test vehicle's exhaust system. This corresponds to a serious head-on collision in which the refrigerant line is severed and the reproducible results demonstrate that refrigerant which is otherwise difficult to ignite under laboratory conditions can indeed prove to be flammable in a hot engine compartment. Similar tests of the current R134a refrigerant did not result in ignition.
Due to their findings, Mercedes-Benz states they will not use this chemical refrigerant in its products. The company therefore wishes to continue to use the proven and safe R134a refrigerant in its vehicles.
Daimler has already informed the relevant authorities of these facts and will also make the results of the investigation available to all relevant associations as well as to other vehicle manufacturers.
This is the refrigerant that was supposed to provide a large portion of the 3 to 5 mpg increase in CAFÉ per the 2025 mandate.
Air Conditioning Improvement Credits
As proposed, EPA is establishing that the maximum total A/C credits available for cars will be 18.8 grams/mile CO2-equivalent and 24.4 grams/mile for trucks CO2-equivalent. The approaches used to calculate these credits for direct and indirect A/C improvement (i.e., improvements to A/C leakage (including substitution of low GHG refrigerant) and A/C efficiency) are generally consistent with those of the MYs 2012-2016 program, although there are several revisions. Most notably, a new test for A/C efficiency, optional under the GHG program starting in MY 2014, will be used exclusively in MY 2017 and beyond. This credit flexibility is required by EPCA/EISA further broken down by 5.0 and 7.2 g/mi respectively for car and truck A/C efficiency credits, and 13.8 and 17.2 g/mi respectively for car and truck alternative refrigerant credits.
All told, this is an easy 3 to 5 MPG gimme.
If I find the Mercedes release at some point in the future, I will be sure to post it back to this story.