I haven't broke in a DL on Amsoil,but have converted rather quickly.Have swapped after a gallon. I did start my new DA 100 out on Amsoil sabre with a 80 to 1 mix. kept good watch on the engine temp and cannister temp. broke it in in the air. I don't think it's necessary to take it down to 40-1. Talked with Amsoil engineer and he said a mix of 400-1 wouldnt cause damage to an engine. I wouldn't try this though.