My 2008 CVPI is also a former federal fleet car. It came from Santa Fe, although I don't know what agency owned it. It's the best car I've ever driven. Loves highway miles, which is 90% of what I drive. Had 117K when I bought it almost three years ago. Has 155K now. Running 10K mile OCI's, it loses less than 1/2 quart of oil.
It runs much quieter on PUP 5W/30 than Napa syn-blend 5W/20. Perhaps because of Pennzoil's formula, or perhaps because of the heavier weight.
But it gets about 5% better MPG on Kendall's GT-1 Max Full Synthetic in 10W/30. My driving routine, traffic, tire pressure, air-conditioner use, etc. is the same, day in, day out, with little variation. The only variable that changed to account for the improved MPG is the Kendall oil, and it was noticeable from the first full fill-up after I changed the oil. I averaged 20.5-21 MPG with PUP. I average 22-23 MPG with Kendall.
I've been using Wix filters but might switch to something else next oil change since 10K might be pushing the life of that filter a bit.
I second the above poster who suggested replacing the other fluids as well. I replaced the tranny pan with one that has a drain plug to make it easier to drain and fill the tranny fluid.
HTH!