Oh, that's right- I was thinking of the MB 229.51 spec that did allow for 40 weight. So there's essentially no daylight at all between the 5w30 and 0w30 507 oils in the Florida climate. Most of the new cars now use 0w20. That must really set some old geezers pants on fire, lol.I repeat, there isn't a 40 weight 507 oil. The spec doesn't allow it.
5w40 was never approved for these engines...because no 5w40 is 507 spec....so the difference between 0w30 and 5w30 is little to nothing. This is not a issue at allI guess after some discussion here the old system of grading oil's effectiveness has changed and a 5-40w oil recommeded is now 0-30w. I am not concerned about the 0W because I live in a constant mild to hot climate,but the upper end of 30W vs 40W is enough protection when towing or high speed driving at 90 degrees. Something goes wrong long past warranty and it's on you to foot the bill. Sounds normal these days.