I am around 8,000 miles so far on the oil inside my 2AZFE engine in my 2008 xB... With Pennzoil Ultra, at 7,500 OCI I had plenty of additive left. This is my first time using the Toyota oil and wondering what type of mileage I can expect. Will I be good up to 10,000 on this engine? I may not make it that high before I change it before winter, but just for peace of mind now. Driving is about 1/2 freeway and 1/2 city. I plan to test the oil when I drain to see how it does, or if I want to go back to Pennzoil Ultra which performed amazing in my engine. Thanks!