Interesting thread. Have any of you tried these new oils on the market from Castrol, Valveline, Quaker State, etc. that say they are for high mileage engines and help reduce oil burning/leaking? I tried the 10w-40 High Mileage Oil in my 93 850 and she seems to burn less oil on the highway now. My 1800 has low mileage, but it's all original so the seals are probably all dried out. 20W/50, from my experience, gives a slight hit in performance because it's so heavy. I've only used it in the past in motors that leak or burn oil. Is there any other reason to go with it?

I've got a leak in my trans that I'm going to have a closer look at this weekend. Not sure if it's the trans or O/D, but it's a slow leak. Any ideas what seals to look at first? Could it just be the seal on the O/D bottom plate?