Pennzoil 'Oil finder site' recommends their 5w30 PU. Ford manual says only 5w20. The Boss302 and Trac pac cars are spec'd with 5w50 for the same motor. Any ideas as to any issues with Ford over warranty coverage? I want to use the best oil for my garage queen. I wonder if my dealer will put 5w30 in if I bring them the oil? I guess I can ask. Or I will just do my own changes again. I just want the Ford dealer records to show history of my services.