OEM fluid is Esso LT71141. I'm ready to change fluid/filter and my indy mechanic uses Pentosin ATF1. From what I can find out it's a full synthetic, whereas the LT71141 is semi-synthetic. I'd like to switch to full synthetic. Was going to use the new formula Mobil 1 ATF but for some reason we only get the original formula in Canada. Car is a 1999 740iL. Thanks.