If you care anything about your engine, and are looking to keep it for 100,000 plus miles, you will use Mobile 1 or Amsoil, and use their high capacity filter. There have been many stupid things said in this post and many misunderstandings about synthetic oil. I'm not a mercedes expert, and still learning about my car. I do know something about lubricants, and shade tree mechanics can say whatever, but I've seen enough engines in my lifetime, and enough teardowns to know that either of those two brands is what you need to be using. Everything else is just not as good. I can say this as someone who worked at a major powertrain plant and have seen it all after teardowns. If you want to use conventional motor oil, your engine seals will get harder faster! FACT. Hard seals leak oil. Changing over to a synthetic will not cause the problem, the problem was already created by conventional motor oil. Ask yourself this......why do they go longer between oil changes in europe? why are we suckers for the 3000 mile oil change? why are we still wasting time with conventional oil????? The oil companies want to sell oil. simple. Any lubricant expert will tell you, change to mobile 1 or Amsoil, and you can go longer between oil changes, especially with the better oil filters. (the problem with americans are ....that we are too lazy to check oil between changes, so we have to change it every 3000, otherwise can you imagine all the lock-ups from running out of oil!!!!!) And!!!! If you really want to talk oil filters, cut them open guys. You will see what a piece of crap FRAM builds. Quit using all the crap and change over to Mobile 1 or Amsoil.