I noticed on the wifes Toyota Camry 06-V6 with 160,000 miles that it is just now starting to use some oil say a quart every 7,000 miles and that it is seeping out of one of the valve covers. Not that a quart every 7K is much but im thinking about a High millage oil? this car has had a diet of PP or Shell Full synthetic all its life. If I do switch to a HM oil is the Penzoil HM a good one? or is there another I should look at?