What could cause a decrease in oil consumption?

[SoNic67]

Isn't the BMW LL-01 basically a 0W-40 oil? No wonder that the oil consumption with 5W-30 was higher...

 

[MCompact]

Originally Posted by SoNic67
Isn't the BMW LL-01 basically a 0W-40 oil? No wonder that the oil consumption with 5W-30 was higher...


LL-01 oils can be 0W-30(FE), 5W-30, 5W-40, or 0W-40.

 

[kschachn]

Originally Posted by MCompact
LL-01 oils can be 0W-30(FE), 5W-30, 5W-40, or 0W-40.

Yes but all Longlife-01 approved oils have a minimum HTHS of 3.5 which puts them within scatter of each other. LL-01FE is a different matter and non-FE LL-01 oils can also be 0W-30. It sounds as though your shop used an ILSAC 5W-30.

 

[DGXR]

This happens sometimes when an engine is known for getting stuck rings if maintenance isn't always kept up. (I'm not saying your engine is known for this, I'm just saying it happens.) When the maintenance is stepped up and/or higher quality oils are used, it takes some time but the stuck ring sometimes gets freed, eventually. When it happens, most often it's when the vehicle changes hands to a more conscientious owner such as yourself.

 

[Triple_Se7en]

C2 Stop Leak worked in my daughter's former Alero. Two treatments in two 3K OCIs. Cut her consumption 60-70%.