Recently purchase a high mileage Honda Fit (110,000+}. I noticed the owner has been using 5w-30 for the last several oil changes. Was wondering if I should go ahead and switch to a 0w-20 now? Or maybe a 5w-20? I have used Mobil 1 in our Acura and it would be nice to not have to have too many oils in my stash. Any recommendations are appreciated.