I switched to Syntec 5w20 in my TL. I had been using Motorcraft 5w20 SynBlend, which is a very very good oil. As soon as I turned the key, the valvetrain was significantly quieter. I won't get MPG numbers until next week. I'm back at a client in downtown Houston and have been taking the bus. Thus far, I like it. It may be an underrated oil. I know some here don't like Syntec because of Castrol's marketing blunders of the past and present. It has no impact on how well the oil runs and I have to say, I'm truly impressed.