I haven't had any problems with synthetic's. I use both Royal Purple and Mobil 1. When Mobil 1 first came out there was alot of complaints of gasket leakage, which I also found, but they put in some additives that have seemed to cure that. In my daily drivers I use Rotella and synthetics in the trans. Joe ************************************** See what's free at http://www.aol.com. [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.