^^Looks clean. I have never used Pennzoil personally but I have seen sludge issues from it, but I have learned that there is usually more to the story, such as someone did not change oil at very good intervals pertaining to use of motor. Overheat, yada, yada, yada.....
I would recommend as stated earlier for a conventional oil to use Valvoline. Winter time I run 5w30 and summertime a 10w30. Keep track of your intervals, I am pretty old school and change oil at 3000 or base it off of use. If I am at 2500 miles before next oil change but I know I have a high load situation coming up I will just do an oil change.
I have switched both of my vehicles over to mobile 1 synthetic and I run a half quart of marvels oil mixed with them. This seems to helps with any sludging build up. I only go 4000 before oil changes with that. My experiences and history with hp and motors will not allow me to ever go for the high mileage oil changes. A lot of those high mileage ratings from OEM's is to show a low maintenance cost to the consumer.
Running a good quality fuel will also help keep oil temps down, no you will not be able to see this unless you get an oil temp gauge, but what you are doing is allowing the combustion chamber to burn a little cooler and piston to not be as hot, therefore the transfer of heat to the oil from piston is less. I'm done rambling.
Cam-shaft.
