I recently picked up a nice 2003 F150 Heritage with a 5.4L, and 71k miles. The previous owner had oil changes done at the local dealer, who used Motorcraft 5w20 synthetic blend oil. I've put 3k miles on it so far.
About halfway through the 3k I've put on it, after an 8 hour trip to trailer a motorcycle home that I bought, I had to add a half quart. Then at 3k, I added about .25 qt. There is no smoking, no smoke / oil smell to the exhaust, and no oily film when I hold my hand in the exhaust gases.
1) Could anyone tell me if this should be considered normal or problematic?
2) Also, I'd like to switch to Pennzoil when I do the next oil change. Is there any issue of switching from synthetic blend to regular Pennzoil? I've heard in the past that it is not recommended to switch back and forth from full synthetic to regular oil, but I'm not sure if this is an issue to consider here.
3) If I do switch to Pennzoil, should I stay with 5w20, or considering the consumption I'm seeing, possibly move to 5w30, or 5w40, or possibly the High Mileage formulation?
Any suggestions would be greatly appreciated.