I'm not too impressed with Brad Penn oil. I've found it to break down pretty quickly when oil temps start reaching 260-270*
Here's a cut from an old OSO post.
I'll share my experiences with Brad Penn oil.
Up until last summer (2005) I had been running Pennzoil 20-50 (engine builders recommendation) I change my oil every 10 hrs and it seemed to work pretty well, no oil pressure issues, oil temps @230 after an occasional hard run 260 (measured before the cooler)
Toward the end of last season I had switched to Brad Penn 20-50 and was not very impressed to say the least. In June I trailered over to Lake Winnipesaukee for Laconia weekend.I had just done a fresh oil change for the trip. We did a lot of boating the first couple days. After three days of running Brad Penn (8 hrs run time) I noticed a loss of oil pressure. My boat normally runs about 60 lbs after warm up while cruising. We were cruising along at no more than 4000 rpm when I noticed the oil pressure dropping. It dropped to 40 lbs, then 30 lbs, I backed down to 3500 and pressure dropped to 20 lbs.
I thought It was engine trouble and stopped for a while. Upon restart, oil pressure returned to normal, 60 psi but soon dropped back to 20 after temps warmed up to normal.
It appears that the Brad Penn oil was all done at 8 hrs and was breaking down at less than 220 degrees oil temp.
I've since changed to Mobil 1 (V-Twin) and all has been fine since. The Mobil oil seems to be pretty consistent, no pressure fluctuations at all and more oil pressure.
Take it for what it's worth, just my personal experience.
Kurt