I have a 99 camry V6. I bought it when it had 158K miles on it and now it has 186K.
I have used only Valvoline Maxlife Synthentic blend 5W-30 for the past 30K miles.
I did an oil change this past weekend and used Synpower 5w-30 with the O'Rielly rebate going on. I was a bit skeptical about using a synthetic first for this high mileage but the car didn't consume any oil for the past 30K miles so I decided to try the full synthetic. About 275 miles since oil change and so far so good. No smoke or burnt smell. Smooth (probably a bit "peppy" than maxlife, but could be perception with the new oil). The gas tank does seem to like the Synpower better as it's got a bit more fuel left in it than otherwise with Maxlife. No change in driving habits, routes, weather, AC use etc. I am only at half tank at this point and seem to be 15 to 20 miles ahead than usual. In hindsight, based on the overall (percieved??) behaviour now and the seemingly higher mpg (I will know for sure in a few days), the maxlife did seem to be a bit more viscous/heavy than the synpower.
I will update on the MPG and the effects (if any) of "full synthetic" on this high mileage car.
BTW, Pennzoil just introduced a new formulation in conventional dino oil line. The 10w-30 High Mileage is GF-5 compatible now. It's at walmart. I picked up a 5qt jug of that one too, but decided to try the synpower first. If the Synpower "leaks", I will try the pennzoil 10w-30 high mileage new formula.
Hope this helps.
