Posting this for my friend. He is making the switch to synthetic next week and decided to go with Pennzoil Platinum. He just isn't sure what grade to go for. - 2.4L engine, auto - will be using the same grade all year - 80-90% city driving - winters average at about 35 degrees - summer highs of high 80's to 90's - OCI every 6 months, about 6k on oil Honda's factory fill is 5w20 on the 2.4L. So what would you say?