Well we've racked up 5k for the first time on Pennzoil Platinum on the wife's 2006 Suzuki Aerio 2.3L. I remember reading that some folks were saying they had usage issues. We used it from 25k-30k(so far) and the car has not used 1 drop of PP. Stuck with the OEM suggestion of 5w30. Running a regular white Purolator if anyone is wondering. MPG's do seem to be doing better even though it's hard to say it's the PP. But the car has always averaged about 26-27mpg/tank. Lately it's averaging 28-29mpg/tank. Has not dropped below 28 which is impressive. Since new I've been running whatever 5-30 dino was on sale w/5k changes. Think we might stick with the PP and do 7,5k intervals as the book calls for 5k-7,500 intervals.