Is all of this high millage motor oil stuff really necessary? I mean isnt a good bottle of you choice good enough for the job? I`ve got over 100k on my RX and am not even considering high millage stuff.
I decided to try Maxlife because my old Dakota was leaking. After 2 oil changes it has virtually stopped leaking. So I think it depends on whether or not you have a reason to try the high mileage stuff.
I use MaxLife in most of our vehicles just because it's good oil. None of them have issues that require a high mileage oil, and a few of them don't even have "high miles". High mileage oil just has higher concentrations of cleaners and seal conditioners than regular oil, that stuff is good for your engine so why not use an oil that has more? I think its kind of preventive maintenance. And MaxLife returns stellar UOAs time after time.
Maxlife can help with leaks and it does protect engine internals better. But it is also manufactured to the thicker side of the given viscosity, which can affect your MPG. I didn't have any leaks but I used it for about 30,000 miles then used Napa HM for 10,000 miles. I noticed my truck was a bit sluggish on HM oil. My truck runs a bit faster and my MPG went up a couple miles too when I switched back to Napa conventional 10W30.
Maxlife is a great oil but there are trade-offs in gas mileage and performance. It is also not rated energy conserving by the API.
HM oils aren't for everybody. If everything you're doing is working out for you. Don't change it. Simple case of "if it ain't broke, don't fix it". HM oils are definitely great for cars that don't have a good or clear maintenance history.