I wouldnt do it. Not because of any other reason then. I couldnt leave oil in my engine or tranny or axles, that long. Ya it will mix, conventional synthetic, what ever. To me, It doesnt matter what those people that market there product say. Foreign auto mfg use creative marketing tools, then people actually believe them. I giess if your going to change it every 5000 miles, go ahead. 10000 miles or more. Good luck