As I said, most any premium oil IF CHANGED OFTEN ENOUGH will have good long term results.

I started using Delo in my diesels about 15 years or so ago. The universal grade oils such as this have much more detergent type additives to deal with the soot present in diesel engines. The oil also, however, has the highest gas engine rating available so I started using it in my gas engines as well. It keeps gas engines squeeky clean inside.

There is a common oil test that is done and the score is called Total Base Number (TBN) Delo has a very high TBN.

In my climate, 15W40 works well year round. In your climate using a lighter oil in the Winter might be warranted.

madbach300e,

The 124 car does not have a vacuum controlled heater valve. It is totally electric receiving its signal from the CCU. A vacuum problem can, however, cause the fresh air door to remain open. This will result in elevated vent temp but not HOT air out the vent.

Have a great day,

Have a great day,