2005 Ford Mustang GT - 4.6L (bought it new)
Changed at 375,000 miles on Oct 26th, 2019
Pennzoil 5W-30, 100% of it's life - (NOT synthetic)
For the last 100K it has been the high mileage 5W-30 blend.
Fram - Tuff Gard this time (I use Fram 90% of the time)
Oil is changed EVERY 5000 miles
I'll change it again at Thanksgiving and put it away for the winter.
No burning no leaking.
Had to replace the timing chain tensioners at 300K and the inside of the engine looked brand new. No wax build up what so ever.