Originally Posted by Benz Mondi

Our cars were designed for R-12 and works best with R-12. Keep using R-12 for as long as you can. R-134 doesn't cool as effectively as R-12. It's a poor substitute for an R-12 system. Conversion is a lot more work and expense that you think. You'll also need to replace the hoses, since the R-134 molecules are smaller than R-12. Otherwise, you'll have leaks and need to re-charge next year, I'm told.