Looking to add a little HP and Torque when towing 26' TT with my '00 2500 Auto 3. 54. Went to local shop to ask about Edge EZ I've seen advertised. They didn't have one but had a BD PNP. Said BD owns EDGE now and PNP is actually a little better. Plugged one in for a test drive and was impressed with added umph. I did feel a little shudder when mashing pedal to change lanes. Technician seems to feel Torque Converter is going out. Any ideas, suggestions or comments? Also, any feedback on Amsol Synthetic vs Rotella T?