With as many miles as I'm driving now, 400+ a week, I'm thinking of switching to Mobil 1 Extended Performance. Since I burn 1qt every 4-5k, I'd probably top off with my stash of Mobil Super Syn. With AAP deal, I can get the 5.1qts and a Mobil 1 filter for about the same price as PP with a P1 filter, Mobil 1 Extended Performance about $2-3 more but I can go longer. Since the car only take 4.5qts I'd only use probably 1qt of mobil super syn during the OC. I'd run the first run of Mobil 1 Extended Performance to 10k and do a used oil analysis and then go from there for my next OCI. Thoughts on my new plan?