As many have stated (in the back log) in the every so often A/C refrigerant debate, "don't change from R-12 because R-134 is less efficient and will not work as well." Well, I can speak from experience as my DeLorean has been converted to R-134. The system works very well. I have to even turn the system down as it becomes too cold at times. Both R-12 and R-134 are viable products. If the system is working properly, why bother change. However, if the owner wishes to change the system to R-134, after the initial cost (about $150 for me), you shouldn't have any other concerns. Many of the comparisons of how well the 134 works have been made based on experiences on other car types. The DeLorean cockpit is very small and therefore has a smaller volume to cool than most other car types. Maybe in vehicles that have a large volume to cool, the efficiency of the 134 would be an important issue, but in the DeLorean (at least mine), the temp. is as cool as you want it to be. You know what everybody says about opinions... Sean Howley VIN#2345 > It is possible to convert the DeLorean system (which is an off the shelf GM air conditioner) to R134, but you will wind up with a higher failure rate of components (due to the high pressure) and probably a less effective air conditioner.>