I have owned my 1986 190E 2.3-16 since it was new, and it now has 210,000 plus miles, and is being driven by my 17 year old son. I told him at about age 3 he could have the car when he turned 16. Well, there are very few things he listened to that came from Dad over the years but he did remember that line, and held me to it.
The point is, I have used Redline MTL in that car, and all my other manual transmissioned Mercedes-Benz vehicles (the 1982 240D now has 290,000 or so miles on it) since the first fluid change. I have been very satisfied with the results. I also use Redline Shockproof lube for the differential, also with very good results.
I have used the early formulations of Mobil 1, Castrol Syntek 5W-50, Mobil 1 15W-50, Mobil 1 0W-40, and now use Mobil Delvac 1 5W-40 synthetic oils in all my cars. I find the Delvac 1 superior for leaving the least dirt and discoloration on the inside of the engine, lowest oil consumption and great cold starting in my Diesels.
Good luck, and enjoy the car, it is a unique bit of machinery. Jim
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)