15w50 too thick?
Thread Starter
Member
Joined: Jun 2013
Posts: 115
Likes: 0
From: Tijuana Mexico
99 E320 W210
15w50 too thick?
i just put synthetic 5w40 chevron delo in my e320 a few weeks ago runs great. looking in the service booklet that came with my car, I noticed the mb dealer put 15w50 Castrol when the car only had like 40,000 miles!! whats up with that is it ok to use thick *** oil like that on our cars? sometimes I think thicker oil would be best because my car has high miles 225000 and I drive it hard<!-- google_ad_section_end --> 
Senior Member
Joined: Jan 2010
Posts: 301
Likes: 23
1997 E300D
If you look at the recommended oil chart Mercedes sends with their cars you will see that 50 weight oil is fine so long as the temperature where you live does not get low enough to be a problem with the cold rating,15W in your example. Heavy oil protects well but you will sacrifice some fuel efficiency due to the power needed to move the thicker oil.
