(I have run Mobil 1 of 15w50 and now 5w40 (dealer) changed every 5k since 60k miles)

IMO, if you change oil every 5K then you don't need to use Mobil 1 , especially with MB engine where oil reservoir is 7.5 qts. I've used Mobil 1 because I am too lazy to get under my car so I've changed oil every 10K... for several yrs now, and no problem at all . Save your money