[EPHIOS]

Well, you can switch back-and-forth between conventional (factory-fill) and synthetic. They are fully compatible. I have contacted Pennzoil, Castrol, Valvoline and Mobil 1, via email, about their compatibilities. I don't know why you are not getting better MPGs with synthetic oil. I did get about 2 MPG better, after switching to synthetic. The main reason why I switched to synthetic is that I wanted to my engine to last longer. Conventional oil will suffice, however. My recommendation, stick with SYNTHETIC! My xB2's engine runs noticeably smoother.

 

[EPHIOS]

In my pov, I Mobil 1 oil filter is great, but they are too expensive. I use Purolator PureOne, it costs more than twice as less. Stay-off the "orange cans". I mean Frams.

 

[EPHIOS]

Fram USED to make great filters . . .
Back in the 1950s and 60s.

Now, they are pretty much crap.

I agree. If you ever open a Fram filter, the materials and the way they are constructed is horrible. I guess this is the result of mass marketing.