I went out for a pretty hard drive this morning (see
My idea of a relaxing Sunday morning drive) and my oil temp never went above 240. And I was driving WOT for a good bit too. Within a couple of days of bringing my car home, I put a bottle of Redline Water Wetter in my radiator. Part of me wonders if that's helping my oil temps at all. I have no baseline to compare it against though, seeing how I put it in so early. Maybe some of you guys who have been seeing oil temp problems could try it and see if you notice any difference? It's supposed to reduce coolant temps by as much as 30 degrees. It comes in a 12oz bottle and is available at any AutoZone. What I do is wait for the car to cool down, then pour it directly into the radiator. You'll want to use a battery acid filler (or siphon) to suck up 12 oz of the coolant that's already in the radiator first before pouring in the Water Wetter.
I figure it's worth a shot, and I'd be interested to see if it makes a difference for anyone.
Red Line Oil: Coolants and Others