Originally Posted by zeng
Originally Posted by loneryder
229.5 is for gas engine and should be used with a fleece filter for the service reminder system. 229.51/52 is for diesels and their exhaust treatment systems. You can run a 229.51/52 oil in a gasser but your service reminder will not be accurate. Also if you run longer oci's on the 229.51/52 in a gasser you will experience sludging. MB actually experienced this and stopped using .51/52 in gassers.
For years the 3.5 engines came with and used 5w-40 syn oil. They only recently went to 5w-30 for CAFE reasons.
Use whatever 229.5 oil you want but I would stay away from .51/52 oils in your car.
Not trying to argue with you, as I wasn't sure on why sludging being caused by use of 229.51 oils in MB gasoline engines calling for 229.5 when both the specs qualify under similar M 271 Sludge Test specifications ?
Would appreciate if you could provide links describing circumstances leading to stated sludging phenomenon.
There are MB gasoline engines allowing use of 229.5, 229.51 AND 229.52 (as opposed to OP's manuals ),in this regards would inaccuracy of service reminder arises and its mechanisms, other than differences in SaPS levels ?
I don't have any technical links to provide. Basically a story from my Indy MB shop. The man's father spent a career with MB and was an investigator with them the last few yrs of his career, then started this shop 18 yrs ago. They follow MB's recommendations (except 10k oci) and use all MB parts. When the .51 low saps oils came out, dealers had a problem with putting the correct oil in the correct car. Since Mobil 1 said on the label that it could be used in gas engines, they started using the .51 oil in all cars. This Indy shop started seeing sludged engines coming in when the service reminder came on. They called Mobil oil who sent reps in to see them. They were very defensive of the oil. They told him they wanted him to come to HQ (in No. Va. at the time) and talk about it. Never happened. He felt that they were covering things up. After that visit, dealers were told to stop using .51 oil in the gassers. He knows that because the dealers told him. Some on here have said that it has something to do with the gasoline in N America. You can use .51 oil in gas engines. You just can't go 10k miles on it.