I was browsing through Walmart and Meijer the other day and noticed Quaker State Ultimate, Mobil Super Synthetic, Meijer Full Synthetic, and Supertech Full Synthetic are all 20 bucks or less for 5 quart jugs. I'm thinking about making the switch from Mobil Super 5000 that I get for 12 bucks. I change the Mobil Super 5000 every 5000 miles along with a new Motorcraft filter. I'm looking to get 10k+ if I make the switch. Is it worth it er no?